Effectiveness of inactive COVID-19 vaccines against severe illness in B.1.617.2 (Delta) variant-infected patients in Jiangsu, China
Preprint
- 5 September 2021
- preprint
- research article
- Published by Cold Spring Harbor Laboratory
Abstract
The SARS-CoV-2 B.1.617.2 (Delta) variant has caused a new surge in the number of COVID-19 cases. The effectiveness of vaccines against this variant is not fully understood. Using data from a recent large-scale outbreak of COVID-19 in China, we conducted a real-world study to explore the effect of inactivated vaccine immunization on the course of disease in patients infected with Delta variants. We recruited 476 confirmed cases over the age of 18, of which 42 were severe. After adjusting for age, gender, and comorbidities, patients who received two doses of inactivated vaccine (fully vaccinated) had an 88% reduced risk in progressing to the severe stage (adjusted OR: 0.12, 95% CI: 0.02- 0.45). However, this protective effect was not observed in patients who only received only one dose of the vaccine(adjusted OR: 1.11, 95% CI: 0.51- 2.36). The full immunization offered 100% protection from a severe illness among women. The effect of the vaccine was potentially affected by underlying medical conditions (OR: 0.26, 95% CI: 0.03-1.23). This is the largest real-world study confirming the effectiveness of inactive COVID-19 vaccines against severe illness in Delta variant-infected patients in Jiangsu, China.Keywords
This publication has 23 references indexed in Scilit:
- Immunological mechanisms of vaccine-induced protection against COVID-19 in humansNature Reviews Immunology, 2021
- SARS-CoV-2 Delta VOC in Scotland: demographics, risk of hospital admission, and vaccine effectivenessThe Lancet, 2021
- SARS-CoV-2 variants of concern are emerging in IndiaNature Medicine, 2021
- Effect of 2 Inactivated SARS-CoV-2 Vaccines on Symptomatic COVID-19 Infection in AdultsJAMA, 2021
- Immunogenicity and Safety of an Inactivated SARS-CoV-2 Vaccine: Preclinical StudiesVaccines, 2021
- Safety and Efficacy of the BNT162b2 mRNA Covid-19 VaccineThe New England Journal of Medicine, 2020
- Safety, tolerability, and immunogenicity of an inactivated SARS-CoV-2 vaccine in healthy adults aged 18–59 years: a randomised, double-blind, placebo-controlled, phase 1/2 clinical trialThe Lancet Infectious Diseases, 2020
- Safety and immunogenicity of the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2: a preliminary report of a phase 1/2, single-blind, randomised controlled trialThe Lancet, 2020
- Clinical Use of Short-Course and Low-Dose Corticosteroids in Patients With Non-severe COVID-19 During Pneumonia ProgressionFrontiers in Public Health, 2020
- Covid-19: risk factors for severe disease and deathBMJ, 2020