Abstract
AbstractWe conducted a matched retrospective cohort study of two cohorts to estimate inactivated vaccine effectiveness (VE) and its comparative effectiveness of booster dose among older people in Shanghai. Cohort 1 consisted of a vaccinated group (≥1 dose) and an unvaccinated group (3,317,475 pairs), and cohort 2 consisted of a booster vaccinated group and a fully vaccinated group (2,084,721 pairs). The Kaplan–Meier method and Cox regression models were used to estimate risk and hazard ratios (HRs) study outcomes. For cohort 1, the overall estimated VEs of ≥1 dose of inactivated vaccine against SARS-CoV-2 infection, severe/critical Covid-19, and Covid-19 related death were 24.7% (95%CI 23.7%−25.7%), 86.6% (83.1%−89.4%), and 93.2% (88.0%−96.1%), respectively. Subset analysis showed that the booster vaccination provided greatest protection. For cohort 2, compared with full vaccination, relative VEs of booster dose against corresponding outcome were 16.3% (14.4%−17.9%), 60.5% (37.8%−74.9%), and 81.7% (17.5%−95.9%). Here we show, although under the scenario of persistent dynamic zero-Covid policy and non-pharmaceutical interventions, promoting high uptake of the full vaccination series and booster dose among older adults is critically important. Timely vaccination with the booster dose provided effective protection against Covid-19 outcomes.
Funder
Science and Technology Commission of Shanghai Municipality
Publisher
Springer Science and Business Media LLC
Subject
General Physics and Astronomy,General Biochemistry, Genetics and Molecular Biology,General Chemistry,Multidisciplinary
Reference29 articles.
1. World Health Organization. WHO Coronavirus (COVID-19) Dashboard, https://covid19.who.int/ (2022).
2. World Health Organization. COVID-19 Vaccine Tracker and Landscape, https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines (2022).
3. World Health Organization. COVID-19 Vaccines with WHO Emergency Use Listing, https://extranet.who.int/pqweb/vaccines/vaccinescovid-19-vaccine-eul-issued (2022).
4. Chemaitelly, H. et al. mRNA-1273 COVID-19 vaccine effectiveness against the B.1.1.7 and B.1.351 variants and severe COVID-19 disease in Qatar. Nat. Med. 27, 1614–1621 (2021).
5. Lopez Bernal, J. et al. Effectiveness of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines on covid-19 related symptoms, hospital admissions, and mortality in older adults in England: test negative case-control study. BMJ 373, n1088 (2021).