World Journal of Vaccines
ISSN / EISSN : 2160-5815 / 2160-5823
Current Publisher: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 131
Latest articles in this journal
World Journal of Vaccines, Volume 11, pp 1-6; doi:10.4236/wjv.2021.111001
Introduction: The COVID 19 pandemic has prompted the world to implement drastic prevention methods based on limiting population movements that have an impact on public health policies such as vaccination. The objective of this work was to evaluate the impact of these prevention measures on routine vaccination in hospitals since the advent of the pandemic in Senegal. Methodology: This is a retrospective cross-sectional study carried out in August 2020 in the vaccination unit of the Abass NDAO hospital centre. We compared data from the vaccination unit during the period from March to August of the last three years (2018, 2019 and 2020). The parameter studied was the number of vaccine doses administered for the different periods according to the expanded programme of immunization. Results: For the vaccines administered in the sixth week in April, the number of doses was 36 in 2018, 29 in 2019 and 15 in 2020, i.e. a 50% drop compared to March. In July the number of doses administered was 40 in 2018, 35 in 2019 and 15 in 2020, a reduction of 42% compared to 2019. Conclusion: Measures to fight this pandemic should not make us forget routine vaccination, especially in our resource-constrained countries. It is essential to continue vaccination for children and to identify children who have missed vaccine doses for catch-up.
World Journal of Vaccines, Volume 10, pp 55-75; doi:10.4236/wjv.2020.104005
World Journal of Vaccines, Volume 10, pp 17-31; doi:10.4236/wjv.2020.101002
The significant function of Toll-like receptors (TLR) is the detection of microbes by host guard cells that guide to the innate immune responses and to the successive adaptive. The current study patterns of TLR2, TLR3 and TLR9 expressing antigen presenting cells (APCs) in blood of mice after colonization with L. plantarum NC8 strain were assessed. The power of L. plantarum on serum innate cytokine and TLR responses stimulated by recombinant NC8-pSIP409-pgsA-VP6-DCpep, NC8-pSIP409-pgsA-VP7-DCpep and NC8-pSIP409-pgsA were also assessed. We confirmed that L. plantarum NC8 stimulated powerful TLR2 expressing APC responses in blood Recombinant strain stimulated a TLR3 response in spleen, and TLR9 responses were stimulated in blood or in spleen. Recombinant NC8-pSIP409-pgsA-VP6-DCpep, NC8-pSIP409-pgsA-VP7-DCpep on TLR2 and TLR9 expressing APC responses has a preservative outcome, reliable with the DCpep adjuvant outcome. In serum the recombinant NC8-pSIP409-pgsA-VP6-DCpep, NC8-pSIP409-pgsA-VP7-DCpep has increased the IL-4 and IFN-γ responses, except that on the TLR3 and TLR9 expressing CD14 APC responses it had an oppressive consequence in spleen and the IFN-α response in serum-stimulated by PRV. Our results give details that following PRV infection after immunization with NC8-pSIP409-pgsA-VP6-DCpep, NC8-pSIP409-pgsA-VP7-DCpep, the systemic TLR2, TLR3, and TLR9 expressing cDC and macrophage/monocyte responses.
World Journal of Vaccines, Volume 10, pp 33-42; doi:10.4236/wjv.2020.102003
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World Journal of Vaccines, Volume 10, pp 1-16; doi:10.4236/wjv.2020.101001
Hydro-Pericardium Syndrome (HPS) is viral problem of commercial poultry caused by aviadeno virus type-4. In Pakistan the problems have been controlled by administering inactivated infected liver homogenate vaccine (ILHV). The use of liver based HPS vaccines remained potential threat for having hypersensitivity reactions in poultry. The current study was carried out to compare the serological potency of HPS ILHV to vero cell line adopted vaccine in term of anti HPS-ELISA antibody titers. 14 HPS virus vaccines were prepared based on different concentration of antigen, type of adjuvants and source of virus substrate. Total of 160 birds were divided into 16 groups each containing 10 birds. At day of 14th age each bird of every group was injected with 0.3 ml dose of respective vaccine. It was observed that HPS infected liver based vaccine having 1 × 105.6, 1 × 105.6 and 1 × 103.6 bird lethal dose 50 induced 1092.10, 875.25 and 702.2 anti-HPS ELISA antibody titer respectively. The 20, 25 and 30 doses/gm HPS infected liver vaccine induced 110.4, 1071.9 and 1037.8 anti-HPS ELISA antibody titer respectively. Montanide based tissue culture HPS vaccine showed significantly higher 1148.45 anti-HPS ELISA antibody titer to aluminium hydroxide based vaccine (137.2) (P 5.6 TCID50 is serological potent against field infection. The vaccines based on such formulation could be prepared in future for effective immuno-prophylaxis against HPS virus.
World Journal of Vaccines, Volume 10, pp 43-53; doi:10.4236/wjv.2020.103004
Background: In Nigeria Pentavalent vaccine had replaced Diphtheria-Pertussis- Tetanus [DPT] vaccine in the prevention of pertussis since 2012. Aims and Objectives: The aim of this study was to compare the anti-pertussis immunoglobin G (IgG) response of children who received DPT with those who received the pentavalent vaccine. Subjects and Methods: This study was carried out in Akpabuyo LGA of Cross River State from April to June 2016. It was a cross-sectional survey of anti-pertussis IgG levels in children aged 6 months to 5 years who received DPT and those who received pentavalent vaccine. IgG antibody levels were determined using enzyme-linked immunosorbent assay. The protective level was set at >11 DU according to manufacturer’s cut off point. Results: Seventy eight out of 230 children [33.9%] who had received DPT had protective levels of anti-pertussis IgG compared to 74 out of 192 children [38.5%] who had received pentavalent vaccine. The difference was not statistically significant [p = 0.61]. The median IgG antibody level in those who received DPT was 8.0 DU (interquartile range (IQR) 4.0 - 13.0) compared with 9.0 DU (IQR) 4.0 - 15.0 in those who received pentavalent vaccine [p = 0.18]. No single factor investigated predicted the development of protective levels of antibody in the multivariate analysis. Conclusion/Recommendation: There was no difference in the antipertussis antibody response between DPT and pentavalent vaccines recipients. Further study is needed to elucidate factors that could be responsible for low anti-pertussis antibody response in this population.
World Journal of Vaccines, Volume 9, pp 71-83; doi:10.4236/wjv.2019.93005
World Journal of Vaccines, Volume 9, pp 1-21; doi:10.4236/wjv.2019.91001
CD8+ cytotoxic T lymphocyte (CTL) exhaustion is one of the major obstacles for the effectiveness of virus control in chronic infectious diseases. We previously generated novel ovalbumin (OVA)-specific 41BBL-expressing OVA-TEXO and human immunodeficiency virus (HIV-1) Gag-specific Gag-TEXO vaccines, inducing therapeutic immunity in wild-type C57BL/6 (B6) mice, and converting CTL exhaustion in recombinant OVA-specific adenovirus AdVOVA-infected B6 (AdVOVA-B6) mice with chronic infection. IL-21 cytokine plays an important role in controlling chronic infections. Therefore, in this study, we constructed recombinant transgene IL-21-expressing AdVIL-21, and generated IL-21-expressing OVA-TEXO/IL-21 and Gag-TEXO/IL21 vaccines, or control vaccines (OVA-TEXO/Null and Gag-TEXO/Null) by infecting OVA-TEXO and Gag-TEXO cells with AdVIL-21 or the control AdVNull, lacking transgene, and assessed their effects in B6 or AdVOVA-B6 mice. We demonstrate that both OVA-TEXO/IL-21 and control OVA-TEXO/Null vaccines are capable of converting CTL exhaustion in chronic infection. However, the OVA-TEXO/IL-21 vaccine more efficiently rescues exhausted CTLs by increasing stronger CTL proliferation and effector cytokine IFN-γ expression than the control OVA-TEXO/Null vaccine in AdVOVA-B6 mice with chronic infection, though both vaccines stimulated comparable OVA-specific CTL responses and protective immunity against OVA-expressing BL6-10OVA melanoma lung metastasis in wild-type B6 mice. In vivo, the OVA-TEXO/IL-21-stimulated CTLs more efficiently up-regulate phosphorylation of mTORC1-controlled EIF4E and expression of mTORC1- regulated T-bet molecule than the control OVA-TEXO/Null-stimulated ones. Importantly, the Gag-TEXO/IL21 vaccine induces stronger Gag-specific therapeutic immunity against established Gag-expressing BL6-10Gag melanoma lung metastases than the control Gag-TEXO/Null vaccine in chronic infection. Therefore, this study should have a strong impact on developing new therapeutic vaccines for patients with chronic infections.
World Journal of Vaccines, Volume 9, pp 49-69; doi:10.4236/wjv.2019.92004
Identifying relevant animal challenge models adds to the complexity of human vaccine development. Murine challenge models have been the most utilized animal model for Chlamydia trachomatis vaccine development. The question arises as to whether the C. trachomatis or C. muridarum pre-clinical model is optimal. We compared C. muridarum and C. trachomatis intravaginal challenge models in a combined total of seventy-five studies evaluating potential vaccine candidates. In 100% (42/42) of C. muridarum studies, mice immunized with Chlamydia elementary bodies (EB) demonstrated a significant reduction in urogenital bacterial shedding as measured by qPCR (p C. trachomatis studies. We have evaluated proposed vaccine antigens in both models and observed immunization with Chlamydia major outer membrane protein (MOMP) vaccine formulations to be protective (p C. trachomatis model, and immunization with PmpD p82 translocator domain was not protective in either model. We also observed in both models that depletion of CD4+ T-cells in MOMP-immunized mice resulted in diminished protective immunity but animals were still able to reduce the infection level. In contrast, mice immunized with live EBs by intraperitoneal route did not require CD4+ T-cells to resolve urogenital infection from intravaginal challenge in either model. Overall, we have found the C. muridarum model to be a more robust, reliable, and reproducible model for vaccine antigen discovery.
World Journal of Vaccines, Volume 9, pp 85-98; doi:10.4236/wjv.2019.94006
Background: The Maternal and Child Survival Program of United States Agency for International Development conducted a study in 2017 to assess the outcome of an initiative to strengthen Expanded Programme on Immunization (EPI) pre-service training. The pre-service training initiative was undertaken by the Ministry of Health (MOH) with support from partners in 2012-2016. The overall objective of the study was to assess the adoption and effectiveness of the initiative in the competency (knowledge, skills and attitude) of graduate nurses. Methods: The study included a conveniently selected sample of 14 pre-service training institutions, 23 field practicum sites, and 29 health facilities in western Kenya, and used quantitative and qualitative methods of data collection. Results: All pre-service training institutions were found to have adapted the WHO EPI prototype curriculum. Overall, tutors followed training method in the classroom as suggested in the curriculum, except evaluation of students’ learning lacked tests or quizzes. Students had opportunities for hands-on practical experience in the field practicum sites. Graduate nurses were found to have acquired the skills for vaccinating children. However, some pre-service training institutions lacked functional skills labs for practical learning of students. In addition, students did not receive up-to-date information on EPI program, and lacked knowledge and skills on monitoring and documentation of EPI coverage during preservice training. Conclusions: It appears that the EPI pre-service training strengthening initiatives facilitated competency-based EPI training of nurses in Kenya. However, preservice training institutions still have scope for improvement in the skills lab, hand-washing practice, providing up-to-date information, and training students on coverage monitoring and documentation.