Protection afforded by post-infection SARS-CoV-2 vaccine doses: a cohort study in Shanghai elifesciences.org - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from elifesciences.org Daily Mail and Mail on Sunday newspapers.
Limited data are available on the effectiveness of inactivated and Ad5-nCoV COVID-19 vaccines in real-world use—especially against Omicron variants in SARS-CoV-2 infection-naïve population. A matched case-control study was conducted among people aged ≥ 3 years between 2 December 2021 and 13 May 2022. Cases were SARS-CoV-2-infected individuals, individuals with severe/critical COVID-19, or COVID-19-related deaths. Controls were selected from consecutively test-negative individuals at the same time as cases were diagnosed and were exact-matched on year-of-age, gender, birthplace, illness onset date, and residential district in ratios of 1:1 with infected individuals and 4:1 with severe/critical COVID-19 and COVID-19-related death. Additionally, two subsets were constructed to analyze separate vaccine effectiveness (VE) of inactivated vaccines (subset 1) and Ad5-vectored vaccine (subset 2) against each of the three outcomes. Our study included 612,597 documented SARS-CoV-
January 22, 2021
Coronavirus Vaccine Mechanism
Scientists around the world are working around the clock to manufacture a risk-free and effective COVID-19 vaccine. Currently, a handful of vaccines have been approved and are being provided to the public worldwide; a lot more vaccines are under development.
Vaccine development involves various steps to ensure the final product is both safe and efficient. Initially, the fundamental research is carried out, once the vaccine candidate is manufactured, preclinical animal studies are conducted in animal models. Then the vaccine enters small phase 1 studies, focusing on safety, and then larger phase 2 studies, with a focus on efficiency.