Change in covid-19 risk over time following vaccination with CoronaVac: test negative case-control study
Year: 2022
Type: article
Study design: Observational Study
Abstract: Objective To estimate the change in odds of covid-19 over time following primary series completion of the inactivated whole virus vaccine CoronaVac (Sinovac Biotech) in São Paulo State, Brazil. Design Test negative case-control study. Setting Community testing for covid-19 in São Paulo State, Brazil. Participants Adults aged ≥18 years who were residents of São Paulo state, had received two doses of CoronaVac, did not have a laboratory confirmed SARS-CoV-2 infection before vaccination, and underwent reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 from 17 January to 14 December 2021. Cases were matched to test negative controls by age (in 5 year bands), municipality of residence, healthcare worker status, and epidemiological week of RT-PCR test. Main outcome measures RT-PCR confirmed symptomatic covid-19 and associated hospital admissions and deaths. Conditional logistic regression was adjusted for sex, number of covid-19 associated comorbidities, race, and previous acute respiratory illness. Results From 202 741 eligible people, 52 170 cases with symptomatic covid-19 and 69 115 test negative controls with covid-19 symptoms were formed into 43 257 matched sets. Adjusted odds ratios of symptomatic covid-19 increased with time since completion of the vaccination series. The increase in odds was greater in younger people and among healthcare workers, although sensitivity analyses suggested that this was in part due to bias. In addition, the adjusted odds ratios of covid-19 related hospital admission or death significantly increased with time compared with the odds 14-41 days after series completion: from 1.25 (95% confidence interval 1.04 to 1.51) at 70-97 days up to 1.94 (1.41 to 2.67) from 182 days onwards. Conclusions Significant increases in the risk of moderate and severe covid-19 outcomes occurred three months after primary vaccination with CoronaVac among people aged 65 and older. These findings provide supportive evidence for the implementation of vaccine boosters in these populations who received this inactivated vaccine. Studies of waning should include analyses designed to uncover common biases.
Source: BMJ
Authors: Matt D.T. Hitchings, Otavio T. Ranzani, Margaret L. Lind, Murilo Dorion, Tatiana Lang D’Agostini, Regiane Cardoso de Paula, Olivia Ferreira Pereira de Paula, Edlaine Faria de Moura Villela, Mario Sergio Scaramuzzini Torres, Silvano Barbosa de Oliveira, Wade Schulz, Maria Almiron, Rodrigo Said, Roberto Dias de Oliveira, Patricia Vieira da Silva, Wildo Navegantes de Araújo, Jean Carlo Gorinchteyn, Natalie E. Dean, Jason R. Andrews, Derek A.T. Cummings, Albert I. Ko, Julio Croda
Institutions: University of Florida Health, University of Florida, Universidade de São Paulo, Barcelona Institute for Global Health, Instituto do Coração - HCFMUSP, Yale University, Secretaria da Saúde, Universidade de Brasília, Pan American Health Organization (Brasil), Universidade Estadual de Mato Grosso do Sul, Universidade Federal de Mato Grosso do Sul, Emory University, Stanford University, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Fiocruz Mato Grosso do Sul
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Funders: Centres de Recerca de Catalunya, Generalitat de Catalunya, Ministerio de Ciencia e Innovación, Fundação Oswaldo Cruz, National Institutes of Health, Pan American Health Organization, Instituto de Salud Carlos III, National Institute of Allergy and Infectious Diseases, National Center for Advancing Translational Sciences
OpenAlex ID: W4282595455