It is critical to identify high-risk groups among children with COVID-19 from low-income and middle-income countries (LMICs) to facilitate the optimum use of health system resources. The study aims to describe the severity and mortality of different clinical phenotypes of COVID-19 in a large cohort of children admitted to tertiary care hospitals in India. Children aged 0–19 years with evidence of SARS-CoV-2 infection (real time polymerase chain reaction or rapid antigen test positive) or exposure (anti-SARS-CoV-2 antibody, or history of contact with SARS-CoV-2) were enrolled in the study, between January 2021 and March 2022 across five tertiary hospitals in India. All study participants enrolled prospectively and retrospectively were followed up for three months after discharge. COVID-19 was classified into severe (Multisystem Inflammatory Syndrome in Children (MIS-C), severe acute COVID-19, ‘unclassified’) or non-severe disease. The mortality rates were estimated in different phenotypes. Among 2468 eligible children enrolled, 2148 were hospitalised. Signs of illness were present in 1688 (79%) children with 1090 (65%) having severe disease. High mortality was reported in MIS-C (18.6%), severe acute COVID-19 (13.3%) and the unclassified severe COVID-19 disease (12.3%). Mortality remained high (17.5%) when modified MIS-C criteria was used. Non-severe COVID-19 disease had 14.1% mortality when associated with comorbidity. Our findings have important public health implications for low resource settings. The high mortality underscores the need for better preparedness for timely diagnosis and management of COVID-19. Children with associated comorbidity or coinfections are a vulnerable group and need special attention. MIS-C requires context specific diagnostic criteria for low resource settings. It is important to evaluate the clinical, epidemiological and health system-related risk factors associated with severe COVID-19 and mortality in children from LMICs. Department of Biotechnology, Govt of India and Department of Maternal, Child and Adolescent Health and Aging, WHO, Geneva, Switzerland.

The inability to predict the evolution of the COVID-19 epidemic hampered abilities to respond to the crisis effectively. The cycle threshold (Ct) from the standard SARS-CoV-2 quantitative reverse transcription-PCR (RT-qPCR) clinical assay is inversely proportional to the amount of SARS-CoV-2 RNA in the sample. We were interested to see if population Ct values could predict future increases in COVID-19 cases as well as subgroups that would be more likely to be affected. This information would have been extremely helpful early in the COVID-19 epidemic. We therefore conducted a retrospective analysis of demographic data and Ct values from 2,076,887 nasopharyngeal swab RT-qPCR tests that were performed at a single diagnostic laboratory in the Czech Republic from April 2020 to April 2022 and from 221,671 tests that were performed as a part of a mandatory school surveillance testing program from March 2021 to March 2022. We found that Ct values could be helpful predictive tools in the real-time management of viral epidemics. First, early measurement of Ct values would have indicated the low viral load in children, equivalent viral load in males and females, and higher viral load in older individuals. Second, rising or falling median Ct values and differences in Ct distribution indicated changes in the transmission in the population. Third, monitoring Ct values and positivity rates would have provided early evidence as to whether prevention measures are effective. Health system authorities should thus consider collecting weekly median Ct values of positively tested samples from major diagnostic laboratories for regional epidemic surveillance.

Coronavirus disease 2019 (COVID-19) is a major global health concern. In contrast to adults, the course of the disease has been observed to be mild or even asymptomatic in children. It is therefore both clinically and epidemiologically important to measure the seroprevalence in children and adolescents to discern the overall morbidity of the disease and to compare these findings with similar data collected globally. We conducted a cross-sectional study between March and July of 2022 at the Children Clinical University Hospital in Riga, Latvia, to evaluate the seroprevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Participants aged 0 to 18 years were enrolled during hospitalization for reasons other than COVID-19. The levels of SARS-CoV-2 spike protein and nucleocapsid antibodies were measured in blood samples. The possibility of transplacental antibody transport was evaluated by directly interviewing the mothers of participants aged 18 months and younger. Various demographic and epidemiological risk factors and their association with seroprevalence were analyzed. Positive SARS-CoV-2 nucleocapsid antibodies were designated the main criterion for seropositivity. Of 200 enrolled children, 173 were found to be seropositive, resulting in an overall seroprevalence of 86.5%. The highest seroprevalence was detected in children and adolescents aged 12 to 18 years. With the progression of the COVID-19 pandemic, the seroprevalence in children has increased significantly. We found that almost 1-third of seropositive children in our study population were unaware of being previously infected with SARS-CoV-2 due to an asymptomatic course of the disease. Our study findings pertaining to high seropositivity among children and adolescents might be beneficial for public authorities to adapt epidemiological strategies and prevention measures. The high seroprevalence rate reported here and in many other populations around the world suggests that COVID-19 will likely become one of the many seasonal viral infections.

Objective To compare concussion rates (CRs) over one academic year in high school athletes with and without a COVID-19 infection prior to concussion. Methods Illness and concussion were prospectively reported for male and female high school athletes across six states over one academic year in the Players Health Rehab surveillance system. Concussion was truncated to 60 days following recovery and return to sport from COVID-19. CRs were estimated per 1000 athletes per academic year and stratified by those who tested positive for COVID-19 infection (with COVID-19) and those who did not (no COVID-19). Poisson regression analyses estimated rate ratio (RR) of concussion controlling for state, gender and an offset of the log athlete participation (with COVID-19 and no COVID-19). Results Of 72 522 athletes, 430 COVID-19 infections and 1273 concussions were reported. The CR was greater in athletes who reported COVID-19 (CR=74.4/1000 athletes/year, 95% CI 49.6 to 99.3) compared with those who did not (CR=17.2, 95% CI 16.3 to 18.2). Athletes with recent COVID-19 had a threefold higher rate of concussion (RR=3.1, 95% CI 2.0 to 4.7). Conclusion Athletes returning from COVID-19 had higher CRs than those who did not experience COVID-19. This may be related to ongoing COVID-19 sequelae or deconditioning related to reduced training and competition load during the illness and when returning to sport. Further research is needed to understand the association of recent COVID-19 infection and concussion in order to inform preventive strategies.

Background: Gestational SARS-CoV-2 infection can impact maternal and neonatal health. The virus has also been reported to cause newborn sensorineural hearing loss, but its consequences for the auditory system are not fully understood. Objective: The aim of this study was to evaluate the impact of maternal SARS-CoV-2 infection during pregnancy on newborn’ hearing function during the first year of life. Methods: An observational study was conducted from 1 November 2020 to 30 November 2021 at University Modena Hospital. All newborns whose mother had been infected by SARS-CoV-2 during pregnancy were enrolled and underwent audiological evaluation at birth and at 1 year of age. Results: A total of 119 neonates were born from mothers infected by SARS-CoV-2 during pregnancy. At birth, five newborns (4.2%) presented an increased threshold of ABR (Auditory Brainstem Evoked Response), but the results were confirmed only in 1.6% of cases, when repeated 1 month later, while the ABR thresholds in all other children returned to normal limits. At the 1-year follow-up, no cases of moderate or severe hearing loss were observed, while concomitant disorders of the middle ear were frequently observed. Conclusions: Maternal SARS-CoV-2 infection, regardless of the trimester in which it was contracted, appears not to induce moderate or severe hearing loss in infants. It is important to clarify the possible effect of the virus on late-onset hearing loss and future research is needed.

Objectives This systematic review aims to identify the secondary attack rates (SAR) to adults and other children when children are the index cases within household settings. Methods This literature review assessed European-based studies published in Medline and Embase between January 2020 and January 2022 that assessed the secondary transmission of SARS-CoV-2 within household settings. The inclusion criteria were based on the Population, Exposure, Outcome framework for systematic reviews. Thus, the study population was restricted to humans within the household setting in Europe (population), in contact with paediatric index cases 1–17 years old (exposure) that led to the transmission of SARS-CoV-2 reported as either an SAR or the probability of onward infection (outcome). Results Of 1819 studies originally identified, 19 met the inclusion criteria. Overall, the SAR ranged from 13% to 75% in 15 studies, while there was no evidence of secondary transmission from children to other household members in one study. Evidence indicated that asymptomatic SARS-CoV-2 index cases also have a lower SAR than those with symptoms and that younger children may have a lower SAR than adolescents (>12 years old) within household settings. Conclusions SARS-CoV-2 secondary transmission from paediatric index cases ranged from 0% to 75%, within household settings between January 2020 and January 2022, with differences noted by age and by symptomatic/asymptomatic status of the index case. Given the anticipated endemic circulation of SARS-CoV-2, continued monitoring and assessment of household transmission is necessary.

Amaç: COVID-19’un yol açtığı şiddetli klinik sonuçlara neden olan risk faktörleri yetişkin hastalarda çocuk hasta grubuna göre daha iyi tanımlanmıştır. Bu çalışmada hastanemize COVID-19 şüphesi ile başvuran ve SARS-CoV-2 testi pozitif saptanan çocuk hastalarda sosyo-demogrofik özellikler, klinik bulgular ve eşik değeri “cycle threshold” (Ct) değeri arasındaki ilişkinin değerlendirilmesi amaçlanmıştır. Yöntem: Çalışmada 1 Mayıs 2020-31 Ekim 2021 tarihleri arasında Mersin Üniversitesi Hastanesi COVID-19 laboratuvarında SARS-CoV-2 RT-qPCR testi pozitif saptanan 2971 çocuk hasta çalışmaya dahil edilmiştir. SARS-CoV-2 RT-qPCR testi, nazofarengeal ve orofarengeal sürüntü örneklerinden yapılmıştır. RT-qPCR sonucundan elde edilen Ct değerleri düşük, orta, yüksek şeklinde sınıflandırılmıştır. Bulgular: SARS-CoV-2 enfeksiyonu pozitif olan çocuk hastalarda en sık görülen semptomlar sırasıyla ateş %41.5, öksürük %28.6 ve boğaz ağrısı %24.4 olarak belirlenmiştir. SARS-CoV-2 pozitif asemptomatik ve semptomatik çocuk hastaların Ct değerleri düşüktür (<24) ve hastalar yüksek risk grubunda yer almaktadır. SARS-CoV-2 pozitif çocuklarda semptomlar ve Ct grupları arasındaki ilişki değerlendirildiğinde özellikle ateş (%43.1), halsizlik (%18.8) ve baş ağrısı (%16.3) semptomu gösteren hastaların yüksek viral yük grubunda olduğu saptanmıştır. Sonuç: Çalışmamızda yer alan temaslı hastaların çoğunun COVID-19’lu aile üyelerinden birine maruz kalması nedeniyle Ct değerinin düşük olduğu düşünülmektedir. Bundan dolayı potansiyel bulaştırıcılıkları yüksek olan bu temaslı grubunun takibi, kontrolü ve izolasyonu halk sağlığı açısından önemli bir noktadır.

Background: Asymptomatic SARS-CoV-2 infections have raised concerns for public health policies to manage epidemics. This systematic review and meta-analysis aimed to estimate the age-specific proportion of asymptomatic SARS-CoV-2 infected persons globally by year of age. Methods: We searched PubMed, Embase, medRxiv and Google Scholar on September 10, 2020, and March 1, 2021. We included studies conducted during January to December 2020, before routine vaccination against COVID-19. Because we expected the relationship between the asymptomatic proportion and age to be nonlinear, multilevel mixed-effects logistic regression (QR decomposition) with a restricted cubic spline was used to model asymptomatic proportions as a function of age. Results: A total of 38 studies were included in the meta-analysis. In total, 6556 of 14,850 cases were reported as asymptomatic. The overall estimate of the proportion of people who became infected with SARS-CoV-2 and remained asymptomatic throughout infection was 44.1% (6556/14,850, 95% CI: 43.3%–45.0%). The predicted asymptomatic proportion peaked in children (36.2%, 95% CI: 26.0%–46.5%) at 13.5 years, gradually decreased by age and was lowest at 90.5 years of age (8.1%, 95% CI: 3.4%–12.7%). Conclusions: Given the high rates of asymptomatic carriage in adolescents and young adults and their active role in virus transmission in the community, heightened vigilance and public health strategies are needed among these individuals to prevent disease transmission.

Background: The acceptance of vaccination against COVID-19 among parents of young children plays a significant role in controlling the current pandemic. A wide range of factors that influence vaccine hesitancy in adults has been reported worldwide, but less attention has been given to COVID-19 vaccination among children. Vaccine hesitancy is considered a major challenge in achieving herd immunity, and it is more challenging among parents as they remain deeply concerned about their child’s health. In this context, a systematic review of the current literature is inevitable to assess vaccine hesitancy among parents of young children to ensure a successful ongoing vaccination program.Method: A systematic search of peer-reviewed English literature indexed in Google Scholar, PubMed, Embase, and Web of science was performed using developed keywords between 1 January 2020 and August 2022. This systematic review included only those studies that focused on parental concerns about COVID-19 vaccines in children up to 12 years without a diagnosis of COVID-19. Following PRISMA guidelines, a total of 108 studies were included. The quality appraisal of the study was performed by Newcastle–Ottawa Scale (NOS).Results: The results of 108 studies depict that vaccine hesitancy rates differed globally with a considerably large number of factors associated with it. The highest vaccine hesitancy rates among parents were reported in a study from the USA (86.1%) and two studies from Saudi Arabia (>85%) and Turkey (89.6%). Conversely, the lowest vaccine hesitancy rates ranging from 0.69 and 2% were found in two studies from South Africa and Switzerland, respectively. The largest study (n = 227,740) was conducted in Switzerland while the smallest sample size (n = 12) was represented by a study conducted in the USA. The most commonly reported barriers to childhood vaccination were mothers’ lower education level (N = 46/108, 43%), followed by financial instability (N = 19/108, 18%), low confidence in new vaccines (N = 13/108, 12%), and unmonitored social media platforms (N = 5/108, 4.6%). These factors were significantly associated with vaccine refusal among parents. However, the potential facilitators for vaccine uptake among respondents who intended to have their children vaccinated include higher education level (N = 12/108, 11%), followed by information obtained through healthcare professionals (N = 9/108, 8.3%) and strong confidence in preventive measures taken by the government (N = 5/81, 4.6%).Conclusion: This review underscores that parents around the globe are hesitant to vaccinate their kids against COVID-19. The spectrum of factors associated with vaccine hesitancy and uptake varies across the globe. There is a dire need to address vaccine hesitancy concerns regarding the efficacy and safety of approved vaccines. Local context is inevitable to take into account while developing programs to reduce vaccine hesitancy. There is a dire need to devise strategies to address vaccine hesitancy among parents through the identification of attributing factors.

Complementing the adult seroprevalence data collected at the time of the rapid SARS-CoV-2 mass vaccination in the district of Schwaz in 2021, we set out to establish the seroprevalence of SARS-CoV-2 among the pediatric population of the district. A total of 369 children, mean age 9.9 (SD 3.4), participated in the study, answering a structured questionnaire on the history of SARS-CoV-2 infection, household contacts, symptoms and history of vaccination. We determined binding and neutralizing antibody levels using plasma samples provided. We estimated the overall prevalence of SARS-CoV-2 infection in the general pediatric population at the time of the study using the census data from Statistik Austria and daily reports of officially confirmed cases. Excluding study participants who reported a history of PCR-confirmed infection, the age-standardized seroprevalence of previously unknown SARS-CoV-2 infection among the general pediatric population of the district was 27% (95% CI: 26.1–27.8). Adding this to the officially documented cases, the true overall prevalence was 32.8% (95% CI: 31.9–33.6) in contrast to the officially documented 8.0% (95% CI: 7.5–8.5) by June 2021. This translated into a proportion of 75.7% (95% CI: 74.4–77.0) of cases being officially undocumented, suggesting a high extent of silent SARS-CoV-2 infections in the pediatric population and possibly silent transmission.

Objectives This systematic review aims to identify the secondary attack rates (SAR) to adults and other children when children are the index cases within household settings. Methods This literature review assessed European-based studies published in Medline and Embase between January 2020 and January 2022 that assessed the secondary transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within household settings. The inclusion criteria were based on the PEO framework (P-Population, E-Exposure, O-Outcome) for systematic reviews. Thus, the study population was restricted to humans within the household setting in Europe (population), in contact with pediatric index cases 1–17 years old (exposure) that led to the transmission of SARS-CoV-2 reported as either a SAR or the probability of onward infection (outcome). Results Of 1,819 studies originally identified, 25 met the inclusion criteria. Overall, the SAR ranged from 13% to 75% in 23 studies, while there was no evidence of secondary transmission from children to other household members in two studies. Evidence indicated that asymptomatic SARS-CoV-2 index cases also have a lower SAR than those with symptoms and that younger children may have a lower SAR than adolescents (>12 years old) within household settings. Conclusions SARS-CoV-2 secondary transmission from paediatric index cases ranged from 0% to 75%, within household settings between January 2020 and January 2022, with differences noted by age and by symptomatic/asymptomatic status of the index case. Given the anticipated endemic circulation of SARS-CoV-2, continued monitoring and assessment of household transmission is necessary.

The viral load of patients infected with SARS-CoV-2 varies on logarithmic scales and possibly with age. Controversial claims have been made in the literature regarding whether the viral load distribution actually depends on the age of the patients. Such a dependence would have implications for the COVID-19 spreading mechanism, the age-dependent immune system reaction, and thus for policymaking. We hereby develop a method to analyze viral-load distribution data as a function of the patients’ age within a flexible, non-parametric, hierarchical, Bayesian, and causal model. The causal nature of the developed reconstruction additionally allows to test for bias in the data. This could be due to, e.g., bias in patient-testing and data collection or systematic errors in the measurement of the viral load. We perform these tests by calculating the Bayesian evidence for each implied possible causal direction. The possibility of testing for bias in data collection and identifying causal directions can be very useful in other contexts as well. For this reason we make our model freely available. When applied to publicly available age and SARS-CoV-2 viral load data, we find a statistically significant increase in the viral load with age, but only for one of the two analyzed datasets. If we consider this dataset, and based on the current understanding of viral load’s impact on patients’ infectivity, we expect a non-negligible difference in the infectivity of different age groups. This difference is nonetheless too small to justify considering any age group as noninfectious.

The SARS-CoV-2 Delta Variant of Concern is highly transmissible and contains mutations that confer partial immune escape. The emergence of Delta in North America caused the first surge in COVID-19 cases after SARS-CoV-2 vaccines became widely available. To determine whether individuals infected despite vaccination might be capable of transmitting SARS-CoV-2, we compared RT-PCR cycle threshold (Ct) data from 20,431 test-positive anterior nasal swab specimens from fully vaccinated (n = 9,347) or unvaccinated (n = 11,084) individuals tested at a single commercial laboratory during the interval 28 June– 1 December 2021 when Delta variants were predominant. We observed no significant effect of vaccine status alone on Ct value, nor when controlling for vaccine product or sex. Testing a subset of low-Ct (<25) samples, we detected infectious virus at similar rates, and at similar titers, in specimens from vaccinated and unvaccinated individuals. These data indicate that vaccinated individuals infected with Delta variants are capable of shedding infectious SARS-CoV-2 and could play a role in spreading COVID-19.

Background: We analyzed the demographic, clinical, and diagnostic data of children and adolescents in Mexico, from the first case of coronavirus disease (COVID-19) to 28 February 2022. Methods: Using the open databases of the Ministry of Health and a tertiary pediatric hospital, we obtained demographic and clinical data from the beginning of the COVID-19 pandemic until 28 February 2022. In addition, quantitative reverse-transcription polymerase chain reaction outputs were used to determine the viral load, and structural protein-based serology was performed to evaluate IgG antibody levels. Results: Of the total 437,832 children and adolescents with COVID-19, 1187 died. Of these patients, 1349 were admitted to the Hospital Infantil de Mexico Federico Gómez, and 11 died. Obesity, asthma, and immunosuppression were the main comorbidities, and fever, cough, and headache were the main symptoms. In this population, many patients have a low viral load and IgG antibody levels. Conclusion: During the first 2 years of the COVID-19 pandemic in Mexico, children and adolescents had low incidence and mortality. They are a heterogeneous population, but many patients had comorbidities such as obesity, asthma, and immunosuppression; symptoms such as fever, cough, and headache; and low viral load and IgG antibodies.

Even if most of the complications due to COVID-19 are observed in the elderly, in Italy the impact of COVID-19 among young people has not been negligible. Furthermore, their contribution to SARS-CoV-2 circulation is still unclear. These reasons have driven policy makers to involve subjects aged 5 to 17 years in the COVID-19 vaccination campaign. However, the trade-off of vaccinating this age-group should be further investigated, especially in view of the rise of new immunologically evasive variants of concern (VOCs). We used regional databases to retrospectively estimate vaccine effectiveness over time of each approved vaccination schedule among children (5–11) and adolescents (12–17). Our findings suggest that COVID-19 vaccines were highly effective and their protection levels lasted longer during a period of Delta variant predominance, whereas they offered just mild to moderate levels of protection—apparently affected by a rapid waning effect—in a period of Omicron variant predominance. Considering these results, it is plausible to evaluate a reformulation of possible future COVID-19 vaccination campaigns among underage subjects. However, effectiveness against serious complications due to COVID-19, as well as indirect benefits of underage vaccinations, should first be addressed. Furthermore, vaccine effectiveness should be kept monitored, as new VOCs may arise, but also new adapted vaccines may start being administered.

Severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2 infection in children and adolescents primarily causes mild or asymptomatic coronavirus disease 2019 (COVID-19), and severe illness is mainly associated with comorbidities. However, the worldwide prevalence of COVID-19 in this population is only 1%–2%. In Mexico, the prevalence of COVID-19 in children has increased to 10%. As serology-based studies are scarce, we analyzed the clinical features and serological response (SARS-CoV-2 structural proteins) of children and adolescents who visited the Hospital Infantil de México Federico Gómez (October 2020–March 2021). The majority were 9-year-old children without comorbidities who were treated as outpatients and had mild-to-moderate illness. Children aged 6–10 years and adolescents aged 11–15 years had the maximum number of symptoms, including those with obesity. Nevertheless, children with comorbidities such as immunosuppression, leukemia, and obesity exhibited the lowest antibody response, whereas those aged 1–5 years with heart disease had the highest levels of antibodies. The SARS-CoV-2 spike receptor-binding domain-localized peptides and M and E proteins had the best antibody response. In conclusion, Mexican children and adolescents with COVID-19 represent a heterogeneous population, and comorbidities play an important role in the antibody response against SARS-CoV-2 infection.

Objective The research on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mainly consists of adult patients, leaving its impact on children understudied. This study aims to investigate the correlations between viral load, clinical course, age, and Alpha variant (B.1.1.7) in children. Methods The study was conducted on children under the age of 18 years, who were admitted to Amasya University Sabuncuoglu Serefeddin Research and Training Hospital in Turkey between February and April 2021. ΔCt values, which were obtained by real-time polymerase chain reaction (PCR), were analyzed to estimate the viral loads of the patients. Alpha variant (B.1.1.7) positivity was determined by real-time PCR. Results There was no difference between estimated viral loads of different clinical courses (p > 0.05), or between asymptomatic and symptomatic patients (p > 0.05). Viral loads were found to decrease with increasing age (p = 0.002). Also, a higher rate of symptomatic disease was found in children under the age of 4 years (p < 0.05). Alpha variant (B.1.1.7) was not found to be associated with severe disease in children (p > 0.05). Conclusion Our results demonstrate higher viral loads and symptomatic disease in children under the age of 4 years. Alpha variant (B.1.1.7) was not found to be related to disease severity. There has not been a consensus on the vaccination of the pediatric population worldwide. More studies are needed to understand the viral kinetics of SARS-CoV-2 and its severity on children to build effective vaccination strategies in children as public health restrictions are eased.

Background: SARS-CoV-2 infection is associated with a wide range of clinical manifestations and severity. Pediatric cases represent <10% of total cases, with a mortality rate below 1%. Data of correlation between SARS-CoV-2 viral load in respiratory samples and severity of disease in pediatric patients is scarce. The cycle threshold (CT) value for the detection of SARS-CoV-2 could be used as an indirect indicator of viral load in analyzed respiratory samples.Objective: The aim of this study was to describe CT values and their correlation with clinical manifestations, epidemiology and laboratory parameters in pediatric patients with confirmed COVID-19.Methods: In this observational, retrospective, analytic and single-center study we included patients under 15 years with confirmed COVID-19 by RT-PCR SARS-CoV-2 admitted to the Isidoro Iriarte Hospital (Argentina) between March 1st 2020 and April 30th 2021.Results: 485 patients were included, the distribution according to disease severity was: 84% (408 patients) presented mild disease, 12% (59 patients) moderate disease and 4% (18 patients) severe disease. Patients with moderate and severe illness had an increased hospitalization rate, prolonged hospitalization, higher frequency of comorbidities and oxygen and antibiotics use. CT values, that could be used as an indirect measure of viral load, was associated with severity of clinical manifestations and age under 12 months. No patient required admission to PICU nor mechanical ventilation. No deaths were registered.Conclusions: In this study, the viral load of SARS-CoV-2 in respiratory samples, determined by the cycle threshold, was significantly correlated with moderate to severe cases and with age.

Purpose: School closures have been used as part of lockdown strategies to contain the spread of SARS-CoV-2, adversely affecting children’s health and education. To ensure the accessibility of educational institutions without exposing society to the risk of increased transmissions, it is essential to establish SARS-CoV-2 testing strategies that are child-friendly, scalable and implementable in a daily school routine. Self-sampling using non-invasive saliva swabs combined with pooled RT-qPCR testing (Lolli-Method) has been proven to be a sensitive method for the detection of SARS-CoV-2. Methods: We conducted a pilot project in Cologne, Germany, designed to determine the feasibility of a large-scale rollout of the Lolli-Method for testing without any additional on-site medical staff in schools. Over a period of three weeks, students from 22 schools were sampled using the Lolli-Method. At the end of the project, teachers were asked to evaluate the overall acceptance of the project. Results: We analyzed a total of 757 pooled RT-qPCRs obtained from 8,287 individual swabs and detected 7 SARS-CoV-2 infected individuals. The Lolli-Method was shown to be a feasible and accepted testing strategy whose application is only slightly disruptive to the daily school routine. Conclusion: Our observations suggest that the Lolli-Method in combination with pooled RT-qPCR can be implemented for SARS-CoV-2 surveillance in daily school routine, applicable on a large scale.

Safe and effective vaccines against SARS-CoV-2 for children are urgently needed. Here we aimed to assess the safety and immunogenicity of an inactivated COVID-19 vaccine candidate, WIBP-CorV, in participants aged 3-17 years. A randomized, double-blind, placebo-controlled, phase 1/2 clinical trial was conducted in Henan Province, China, in healthy children aged 3-17 years. 240 participants in phase 1 trial and 576 participants in phase 2 trial were randomly assigned to vaccine or control with an age de-escalation in three cohorts (3-5, 6-12 and 13-17 years) and dose-escalation in three groups (2.5, 5.0 and 10.0μg/dose), and received 3 intramuscular injections at day 0, 28, and 56. WIBP-CorV showed a promising safety profile with approximately 17% adverse reactions within 30 days after injection and no grade 3 or worse adverse events. The most common adverse reaction was injection site pain, followed by fever, which were mild and self-limiting. The geometric mean titers of neutralizing antibody ranged from 102.2 to 1065.5 in vaccinated participants at 28 days after the third vaccination, and maintained at a range of 14.3 to 218.2 at day 180 after the third vaccination. WIBP-CorV elicited significantly higher titers of neutralizing antibody in the cohort aged 3-5 years than the other two cohorts. There were no detectable antibody responses in all alum-only groups. Taken together, our data demonstrate that WIBP-CorV is safe and well tolerated at all tested doses in participants aged 3-17 years, and elicited robust humoral responses against SARS-CoV-2 lasted for at least 6 months after the third vaccination. This study is ongoing and is registered with www.chictr.org.cn, ChiCTR2000031809.

Introduction. In late 2019, a new subtype of coronavirus named severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) rapidly spread around the world, causing a global pandemic. Initially, the proportion of confirmed cases among children was relatively small, and it was believed that children were rarely infected. Subsequent observations have shown that in children and adolescents, the infection is either asymptomatic or accompanied by minimal clinical symptoms, and therefore the true incidence is under-estimated due to the low level of testing.Aim. To summarize and systematize the results of studies on the prevalence, diagnosis, clinical picture, vaccination and treatment of children with a new coronavirus infection COVID-19.Materials and methods. PubMed searched articles published up to January 15, 2022 using combinations of the following words: COVID-19, SARS-CoV-2, children, pediatrics, adolescents, infants, and school. We read the abstracts of 101 articles and selected 78 articles based on their relevance to the topics discussed. We also analyzed 3 articles on vaccination of children. A total of 89 articles were included in the review.Results. The SARS-CoV-2 positivity rate throughout the peak of the pandemic in children was low compared to adults, including those who had an acute respiratory infection. Children are not only less likely to become infected with the virus, but they also carry the infection more easily than adults. The mortality rate in children with COVID-19 was < 0.5%. In most children, infection is either asymptomatic or accompanied by an erased clinical picture. Vaccination of children and adolescents is recommended mainly to achieve herd immunity in all age groups. However, there are no convincing data on the duration of the immune response, the level of the required protective antibody titer, as well as on the long-term side effects of vaccination due to the insufficient follow-up period and the uncertainty of the immune response criteria.Conclusion. As information is accumulated on the viral load of children and adolescents, their role in the transmission of the virus, diagnostic approaches in this age group are optimized. The effectiveness of the treatment was tested on patients admitted to the hospital, and recommendations for treatment were developed. Currently, global research efforts are focused on the protection of especially vulnerable children, the prospects for total childhood vaccination, its effectiveness and safety.

Objectives: This systematic review and meta-analysis aimed to estimate the age-specific proportion of asymptomatic SARS-CoV-2 infected persons by year of age.Methods: We searched PubMed, Embase, medRxiv and Google Scholar on 10 September 2020 and 1 March 2021. We included studies conducted during January to October 2020, prior to routine vaccination against COVID-19. Since we expected the relationship between the asymptomatic proportion and age to be non-linear, multilevel mixed-effects logistic regression (QR decomposition) with a restricted cubic spline was used to model asymptomatic proportions as a function of age.Results: A total of 38 studies were included in the meta-analysis. In total, 6556 out of 14850 cases were reported as asymptomatic. The overall estimate of the proportion of people who became infected with SARS-CoV-2 and remained asymptomatic throughout infection was 44.1% (6556/14850, 95%CI 43.3%-45.0%). The asymptomatic proportion peaked in adolescents (36.2%, 95%CI 26.0%-46.5%) at 13.5 years, gradually decreased by age and was lowest at 90.5 years of age (8.1%, 95%CI 3.4%-12.7%).Conclusions: Given the high rates of asymptomatic carriage in adolescents and young adults and their active role in virus transmission in the community, heightened vigilance and public health strategies are needed among these individuals to prevent disease transmission.

Background: Understanding of the role of children in COVID-19 transmission has significant implications for school and childcare policies, as well as appropriate targeting of vaccine campaigns. The objective of this systematic review was to identify the role of children in SARS-CoV-2 transmission to other children and adults. Methods: MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, and Web of Science were electronically searched for articles published before March 31, 2021. Studies of child-to-child and child-to-adult transmission and quantified the incidence of index and resulting secondary attack rates of children and adults in schools, households, and other congregate pediatric settings were identified. All articles describing confirmed transmission of SARS-CoV-2 from a child were included. PRISMA guidelines for data abstraction were followed, with each step conducted by two reviewers. Results: 40 of 6110 articles identified met inclusion criteria. Overall, there were 0.8 secondary cases per primary index case, with a secondary attack rate of 8.4% among known contacts. The secondary attack rate was 26.4% among adult contacts versus 5.7% amongst child contacts. The pooled estimate of a contact of a pediatric index case being infected as secondary case was 0.10 (95% CI 0.03-0.25). Conclusions: Children transmit COVID-19 at a lower rate to children than to adults. Household adults are at highest risk of transmission from an infected child, more so than adults or children in other settings.

Coronavirus Disease 2019 (COVID-19) has spread across the world, caused lockdowns, and has had serious economic and social consequences. COVID-19 manifests differently in children than adults, as children usually have a milder course of disease, mild symptoms if any, and lower fatality rates are recorded among children. SARS-CoV-2 transmission also seems to be different between children and adults. Many factors are proposed to explain the milder outcome in children, e.g., a more appropriate immune response (especially active innate response), trained immunity, a lack of immunosenescence, and the reduced prevalence of comorbidities. A better understanding of the differences in susceptibility and outcome in children compared with adults could lead to greater knowledge of risk factors for complicated COVID-19 cases and potential treatment targets. We highlight proposed reasons as to why children are less affected by COVID-19 than adults.

Background: Despite their clear lesser vulnerability to COVID-19, the extent by which children are susceptible to getting infected by SARS-CoV-2 and their capacity to transmit the infection to other people remains inadequately characterized. We aimed to evaluate the role of school reopening and the preventive strategies in place at schools in terms of overall risk for children and community transmission, by comparing transmission rates in children as detected by a COVID-19 surveillance platform in place in Catalonian Schools to the incidence at the community level. Methods and findings: Infections detected in Catalan schools during the entire first trimester of classes (September-December 2020) were analysed and compared with the ongoing community transmission and with the modelled predicted number of infections. There were 30.486 infections (2.12%) documented among the circa 1.5M pupils, with cases detected in 54.0% and 97.5% of the primary and secondary centres, respectively. During the entire first term, the proportion of “bubble groups” (stable groups of children doing activities together) that were forced to undergo confinement ranged between 1 and 5%, with scarce evidence of substantial intraschool transmission in the form of chains of infections, and with ~75% of all detected infections not leading to secondary cases. Mathematical models were also used to evaluate the effect of different parameters related to the defined preventive strategies (size of the bubble group, number of days of confinement required by contacts of an index case). The effective reproduction number inside the bubble groups in schools (R*), defined as the average number of schoolmates infected by each primary case within the bubble, was calculated, yielding a value of 0.35 for primary schools and 0.55 for secondary schools, and compared with the outcomes of the mathematical model, implying decreased transmissibility for children in the context of the applied measures. Relative homogenized monthly cumulative incidence ( rCIhom,j ) was assessed to compare the epidemiological dynamics among different age groups and this analysis suggested the limited impact of infections in school-aged children in the context of the overall community incidence. Conclusions: During the fall of 2020, SARS-CoV-2 infections and COVID-19 cases detected in Catalan schools closely mirrored the underlying community transmission from the neighbourhoods where they were set and maintaining schools open appeared to be safe irrespective of underlying community transmission. Preventive measures in place in those schools appeared to be working for the early detection and rapid containment of transmission and should be maintained for the adequate and safe functioning of normal academic and face-to-face school activities.

The impact of specific risk factors for SARS-CoV-2 infection spread was investigated among the 215 municipalities in north-eastern Italy. SARS-CoV-2 incidence was gathered fortnightly since April 1, 2020 (21 consecutive periods) to depict three indicators of virus spreading from hierarchical Bayesian maps. Eight explanatory features of the municipalities were obtained from official databases (urbanicity, population density, active population on total, hosting schools or nursing homes, proportion of commuting workers or students, and percent of > 75 years population on total). Multivariate Odds Ratios (ORs), and corresponding 95% Confidence Intervals (CIs), quantified the associations between municipality features and virus spreading. The municipalities hosting nursing homes showed an excess of positive tested cases (OR = 2.61, ever versus never, 95% CI 1.37;4.98), and displayed repeated significant excesses: OR = 5.43, 3–4 times versus 0 (95% CI 1.98;14.87) and OR = 6.10, > 5 times versus 0 (95% CI 1.60;23.30). Municipalities with an active population > 50% were linked to a unique statistical excess of cases (OR = 3.06, 1 time versus 0, 95% CI 1.43;6.57) and were inversely related to repeated statistically significant excesses (OR = 0.25, > 5 times versus 0; 95% CI 0.06;0.98). We highlighted specific municipality features that give clues about SARS-CoV-2 prevention.

This narrative review sums up data from the SARS-CoV-2-pandemia on preexisting disease/underlying conditions/comorbidities and risk factors in children for severe COVID-19 and MIS-C/PIMS-TS as well as hospitalization and mortality. Young infants and adolescents are at highest risk of hospital and PICU admission. Two or more comorbidities rather than single entities pose a risk for more severe courses of SARS-CoV-2 infection in children. Asthma and malignancy do not increase complication rates. MIS-C/PIMS-TS is not associated with any specific underlying disease.

Objectives COVID-19 (Coronavirus Disease 2019) is now a global pandemic. Although children are said to have mild symptom, their clinical features are not known well. We conducted a retrospective study during initial term of pandemic to understand the difference of clinical features including clinical symptoms and patients’ characteristics of COVID-19 children and those without COVID-19. Materials To compare clinical features between children with and without COVID-19, we collected data on children who received a COVID-19 test between March 25^th and October 31^st, 2020. All data were collected from medical records. Methods There were three groups of patients in the study sample; patients with COVID-19, patients with close COVID-19 contact and performed COVID-19 tests, and patients suspected COVID-19 but tested negative. We analyzed the clinical features of the groups. Results A total of 108 patients were included in this study, of whom 30 were patients with COVID-19, 25 were patients with close COVID-19 contact, 51 were suspected COVID-19 but tested negative, and two were excluded because they were infants born from COVID-19 mothers. The statistical analysis showed that children with COVID-19 had contact with COVID-19 patients had fewer clinical symptoms including cough and fever compared to children with a negative test of COVID-19. Sensitivity analysis showed that fever, cough, fever and/or cough could not distinguish children with COVID-19 from those without COVID-19. As conclusion, children with COVID-19 have less symptoms as fever or cough and the clinical symptoms cannot distinguish them from children with other diseases.

The reported median duration of viral shedding after infection with SARS-CoV2 is between 12 and 20 days. It is now established that infected individuals can continue to shed viral ribonucleic acid (RNA) without shedding live virus. This has implications for quarantine and infection control practices. COVID in the acute phase seems to be milder in children, and the duration of viral RNA shedding is shorter in children compared to adults. SARS-CoV-2 infections in the newborn period is rare. Little is known about the duration of viral shedding in preterm infants with vertically acquired SARS-CoV-2. 3 of the 4 preterm infants cared for at our center had prolonged shedding up to 34 days with live viral shedding not seen beyond the second week when tested in 3 of them.

Coronavirus disease 2019 (COVID-19) is usually less severe in children compared to adults. This study describes detailed clinical characteristics, treatment and outcomes of children with COVID-19 in a non-hospitalised and hospitalised setting and quantifies factors associated with admission to hospital and intensive care unit in children with SARS-CoV-2 infection on a nationwide level. Data were collected through the Swiss Paediatric Surveillance Unit from children < 18 years with confirmed SARS-CoV-2 infection. All 33 paediatric hospitals in Switzerland reported non-hospitalised and hospitalised cases from March 1 to October 31, 2020 during both pandemic peaks. In total, 678 children were included. The median age was 12.2 years (IQR 5.0–14.6), 316 (46.6%) were female and 106 (15.6%) had comorbidities. Overall, 126 (18.6%) children were hospitalised of whom 16 (12.7%) required ICU admission. Comorbidities were the only factor associated with hospital admission in a multivariable regression analysis (odds ratio 3.23, 95%CI 1.89 to 5.50;p-value < 0.01). Children with preexisting comorbidities did not require ICU admission more often. Hospitalised children more often presented with fever (96 [76.2%] vs 209 [38.1%],p-value < 0.01) and rash (16 [12.8%] vs 6 [1.1%],p-value < 0.01). Anosmia/dysgeusia was more prevalent in non-hospitalised children (73 [13.3%] vs 3 [2.4%],p-value < 0.01). In hospitalised children, oxygen treatment was required in 34 (27.0%), inotropes in nine (7.3%) and mechanical ventilation in eight (6.3%) cases. Complications were reported in 28 (4.1%) children with cardiovascular complications being most frequent (12 [1.8%]). Three deaths were recorded.Conclusion: This study confirms that COVID-19 is mostly a mild disease in children. Fever, rash and comorbidities are associated with higher admission rates. Continuous observation is necessary to further understand paediatric COVID-19, guide therapy and evaluate the necessity for vaccination in children. What is Known:• Clinical manifestations of SARS-CoV-2 infection in children vary from asymptomatic to critical disease requiring intensive care unit admission.• Most studies are based on hospitalised children only; currently, there is limited data on non-hospitalised children.What is New:• The clinical spectrum and severity of COVID-19 is influenced by age: in children less than 2 years, fever, cough and rhinorrhoea are the most common symptoms and in adolescents, fever, cough and headache are more common.• Hospitalised children more often presented with fever and rash, while anosmia/dysgeusia is more prevalent in non-hospitalised children.• Children with pre-existing comorbidities are more frequently hospitalised but do not require ICU admission more often.

Aim In this study, we aimed to contribute to the literature by sharing our experiences regarding the major spine surgeries we have applied to juvenile and adolescent patients during the Covid-19 pandemic process. Material and Methods We retrospectively evaluated a total of 26 juvenile and adolescent idiopathic scoliosis and kyphosis patients we operated within a year from April 2020, when pandemic measures were implemented in our country up to April 2021. Results Any respiratory complications or symptoms and signs of Covid-19 were not observed in our patients in the preoperative and / or postoperative period. Conclusion During this pandemic period, it was ensured that major spine deformity surgeries in juvenile and adolescent patients were successfully managed for both our patients and our healthcare personnel.

Objective: To understand which social, epidemiologic, and clinical risk factors are associated with SARS-CoV-2 infection in youth accessing care in a large, urban academic institution.Methods: We conducted a prospective cohort study with case–control analyses in youth who received testing for SARS-CoV-2 at our academic institution in Los Angeles during the first wave of the COVID-19 pandemic (March–September 2020).Results: A total of 27,976 SARS-CoV-2 assays among 11,922 youth aged 0–24 years were performed, including 475 youth with positive SARS-CoV-2 results. Positivity rate was higher among older, African American, and Hispanic/Latinx youth. Cases were more likely to be from non-English-speaking households and have safety-net insurance. Zip codes with higher proportion of Hispanic/Latinx and residents living under the poverty line were associated with increased SARS-CoV-2 cases. Youth were more likely to have positive results if tested for exposure (OR 21.5, 95% CI 14.6–32.1) or recent travel (OR 1.5, 95% CI 1.0–2.3). Students were less likely to have positive results than essential worker youth (OR 0.5, 95% CI 0.3–0.8). Patterns of symptom presentation varied significantly by age group; number of symptoms correlated significantly with age in SARS-CoV-2 cases (r = 0.030, p < 0.001). SARS-CoV-2 viral load did not vary by symptom severity, but asymptomatic youth had lower median viral load than those with symptoms (21.5 vs. 26.7, p = 0.009).Conclusions: Socioeconomic factors are important drivers of SARS-CoV-2 infection in youth. Presence of symptoms, exposure, and travel can be used to drive testing in older youth. Policies for school reopening and infection prevention should be tailored differently for elementary schools and universities.

Introduction: The incidence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections in the Belgian community is mainly estimated based on test results of patients with coronavirus disease (COVID-19)-like symptoms. The aim of this study was to investigate the evolution of the SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) positivity ratio and distribution of viral loads within a cohort of asymptomatic patients screened prior hospitalization or surgery, stratified by age category. Materials/Methods: We retrospectively studied data on SARS-CoV-2 real-time RT-PCR detection in respiratory tract samples of asymptomatic patients screened pre-hospitalization or pre-surgery in nine Belgian hospitals located in Flanders over a 12-month period (1 April 2020–31 March 2021). Results: In total, 255925 SARS-CoV-2 RT-PCR test results and 2421 positive results for which a viral load was reported, were included in this study. An unweighted overall SARS-CoV-2 real-time RT-PCR positivity ratio of 1.27% was observed with strong spatiotemporal differences. SARS-CoV-2 circulated predominantly in 80+ year old individuals across all time periods except between the first and second COVID-19 wave and in 20–30 year old individuals before the second COVID-19 wave. In contrast to the first wave, a significantly higher positivity ratio was observed for the 20–40 age group in addition to the 80+ age group compared to the other age groups during the second wave. The median viral load follows a similar temporal evolution as the positivity rate with an increase ahead of the second wave and highest viral loads observed for 80+ year old individuals. Conclusion: There was a high SARS-CoV-2 circulation among asymptomatic patients with a predominance and highest viral loads observed in the elderly. Moreover, ahead of the second COVID-19 wave an increase in median viral load was noted with the highest overall positivity ratio observed in 20–30 year old individuals, indicating they could have been the hidden drivers of this wave.

COVID-19 continues to spread throughout the world. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) is used to diagnose COVID-19, with its cycle threshold (Ct) value inversely related to the viral load. The association between Ct values and COVID-19 related outcomes has been studied in the hospital setting but less so in the community. We aimed to estimate the association between Ct values and the severity of community-diagnosed COVID-19 to provide evidence on the utility of Ct testing in this setting. This was a retrospective cohort study based on data from Israel’s largest health organization. The study population included 34,658 individuals who tested positive for COVID-19 by RT-PCR and had available Ct values between June 1^st and December 21^st, 2020. Outcomes included COVID-19 related symptoms, hospitalization, severe disease, and death. Ct values were modelled both as discrete and continuous exposures. After adjusting for known risk factors for severe COVID-19, low Ct values were associated with symptomatic disease (odds ratio [OR]: 1.51; 95% confidence interval [CI]:1.21–1.84), hospitalization (OR: 1.27; 95%CI: 1.12–1.49), severe disease (OR: 1.80; 95%CI: 1.43–2.27), and death (OR: 1.64; 95%CI: 1.06–2.59). By modelling the exposure as continuous, we noticed a dose-response relationship, with the risk gradually rising with lower Ct values. This study found a significant association between low Ct values and severe COVID-19 related outcomes, with a dose-response relationship. This suggests that Ct values could be helpful in identifying high-risk patients diagnosed in the community.

Whether all children under 12 years of age should be vaccinated against COVID-19 remains an ongoing debate. The relatively low risk posed by acute COVID-19 in children, and uncertainty about the relative harms from vaccination and disease mean that the balance of risk and benefit of vaccination in this age group is more complex. One of the key arguments for vaccinating healthy children is to protect them from long-term consequences. Other considerations include population-level factors, such as reducing community transmission, vaccine supply, cost, and the avoidance of quarantine, school closures and other lockdown measures. The emergence of new variants of concern necessitates continual re-evaluation of the risks and benefits. In this review, we do not argue for or against vaccinating children against COVID-19 but rather outline the points to consider and highlight the complexity of policy decisions on COVID-19 vaccination in this age group.

The COVID-19 pandemic caused by SARS-CoV-2 has resulted in substantial morbidity and mortality worldwide. Early public health interventions, including the closure of schools, were implemented to prevent the spread of SARS-CoV-2. However, the role of children in community SARS-CoV-2 transmission remains poorly understood as most children with SARS-CoV-2 infection are asymptomatic1 or experience mild disease.2,3 There have been few community-based studies of pediatric COVID-19 cases, and thus there are limited data on the role of children in the transmission of COVID-19.4

To the Editor The article by Chung and colleagues1 reported that SARS-CoV-2 RNA levels as determined by reverse transcription–polymerase chain reaction cycle threshold values were higher in symptomatic participants than in asymptomatic participants among both children and adults. Furthermore, no difference in the SARS-CoV-2 RNA levels was observed between children and adults.

Previously, we demonstrated an 81% reduction in pediatric Emergency Room (ER) visits in Italy during the strict lockdown due to the SARS-CoV-2 pandemic. Since May 2020, lockdown measures were relaxed until 6 November 2020, when a strict lockdown was patchily reintroduced. Our aim was to evaluate the impact of the relaxed lockdown on pediatric ER visits in Italy. We performed a retrospective multicenter study involving 14 Italian pediatric ERs. We compared total ER visits from 24 September 2020 to 6 November 2020 with those during the corresponding timeframe in 2019. We evaluated 17 ER specific diagnoses grouped in air communicable and non-air communicable diseases. We recognized four different triage categories: white, green, yellow and red. In 2020 total ER visits were reduced by 51% compared to 2019 (16,088 vs. 32,568, respectively). The decrease in air communicable diseases was significantly higher if compared to non-air communicable diseases (−64% vs. −42%, respectively). ER visits in each triage category decreased in 2020 compared to 2019, but in percentage, white and red codes remained stable, while yellow codes slightly increased and green codes slightly decreased. Our results suggest that preventive measures drastically reduced the circulation of air communicable diseases even during the reopening of social activities but to a lesser extent with regard to the strict lockdown period (March–May 2020).

Background: This study aimed to explore the association between risk perception and coronavirus disease 2019 (COVID-19) vaccine hesitancy among reproductive women in China to supplement limited studies in this area. Methods: From December 14, 2020, to January 31, 2021, an anonymous cross-sectional online survey was conducted on COVID-19 vaccine hesitancy for children among reproductive women in China. We assessed risk perception, including perceived susceptibility, severity, barriers, and benefits using the health belief model, and then classified each variable into three groups (low, moderate, and high) based on tertiles. Information on sociodemographic characteristics, health status, and knowledge of COVID-19 was also collected. The Pearson χ2-test was used to compare vaccine hesitancy among the above mentioned factors. Logistic regression models were used to calculate the adjusted odds ratio (aOR) of risk perception related to vaccine hesitancy after controlling for the above covariates. Results: Among 3,011 reproductive women, 8.44% (95%CI: 7.44. 9.43) had COVID-19 vaccine hesitancy. Vaccine hesitancy was observed more in women who lived in eastern China (11.63%), aged >45 years (12.00%), had a lower than high school education level (12.77%), and a low score on knowledge of COVID-19 (12.22%). Vaccine hesitancy was associated with lower perceived susceptibility (moderate: aOR = 1.72, 95%CI: 1.17–2.54, P = 0.0061; low: aOR = 2.44, 95%CI: 1.60–3.70, P < 0.0001), high perceived barriers (aOR = 2.86, 95%CI: 1.57–5.22, P < 0.0001), and lower perceived benefit (moderate: aOR = 3.29, 95%CI: 2.30–4.70, P < 0.0001; low: aOR = 4.59, 95%CI: 2.98–7.07, P < 0.0001), but not with perceived severity. Conclusions: Although the proportion of COVID-19 vaccine hesitancy for children among Chinese reproductive women was <1 out of 10, to improve COVID-19 vaccine hesitancy, our findings suggest that tailored public health measures are needed to increase perceived susceptibility and benefit, and decrease perceived barriers among reproductive women.