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Effectiveness of the CoronaVac Vaccine in Prevention of Symptomatic and Progression to Severe COVID-19 in Pregnant Women in Brazil

19 Pages Posted: 12 Nov 2021

See all articles by Enny S. Paixão

Enny S. Paixão

London School of Hygiene and Tropical Medicine

Kerry LM Wong

London School of Hygiene & Tropical Medicine

Flávia Jôse O. Alves

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS)

Vinicius de Araújo Oliveira

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS)

Thiago Cerqueira-Silva

Oswaldo Cruz Foundation (FIOCRUZ) - LIB and LEITV Laboratories

Juracy Bertoldo Júnior

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS)

Tales Mota Machado

Universidade de Brasília (UnB) - Tropical Medicine Centre

Elzo Pereira Pinto Júnior

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS)

Viviane Boaventura

Federal University of Bahia (UFBA)

Gerson O. Penna

Universidade de Brasília (UnB) - Tropical Medicine Centre

Guilherme Werneck

Universidade do Estado do Rio de Janeiro (UERJ) - Instituto de Medicina Social

Laura C. Rodrigues

London School of Hygiene & Tropical Medicine

Neil Pearce

London School of Hygiene and Tropical Medicine

Mauricio Lima Barreto

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS)

Manoel Barral-Netto

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS)

More...

Abstract

Background: The effectiveness of Covid-19 inactivated vaccines in pregnant women is unknown. We estimated vaccine effectiveness (VE) of CoronaVac against symptomatic and severe Covid-19 and in preventing progression from symptomatic to severe Covid-19 in pregnant women in Brazil. 

Methods: We conducted a test-negative design study in all pregnant women aged 18 to 49 years in Brazil, linking records of negative and positive SARS-CoV-2 reverse transcription-polymerase chain reaction (RT-PCR) tests to national vaccination records. We also linked records of test positive cases with notification of severe, hospitalized or fatal Covid-19. Using logistic regression, we estimated adjusted odds and VE against symptomatic Covid-19 by comparing vaccine status in test positive (confirmed cases) to that in subjects with a negative test result. We also calculated the odds/VE against progression by comparing vaccine status in symptomatic cases to that in severe Covid-19 cases. 

Results: Of 19838 tested pregnant women, 7424 (37.4%) tested positive for Covid-19 and 588 (7.9%) had severe disease. Only 83% of pregnant women who received a first dose of CoronaVac completed the vaccination scheme. A single dose of the CoronaVac vaccine was not effective at preventing symptomatic Covid-19. Effectiveness of two doses of CoronaVac was 41% (95% CI 27.1- 52.2) against symptomatic Covid-19, 85% (95% CI 59.5-94.8) against severe Covid-19 and (75%; 95% CI 27.9- 91.2) in preventing progression to severe Covid-19 among those infected. 

Conclusion: A complete regimen of CoronaVac in pregnant women was effective in preventing symptomatic Covid-19, and highly effective against severe illness in a setting that combines high disease burden and elevated Covid-19 related maternal deaths.

Funding Information: This study is part of the VigiVac Fiocruz program, partially supported by a donation from the "Fazer o bem faz bem" program. EPS is funded by the Wellcome Trust [Grant number 213589/Z/18/Z].

Declaration of Interests: We declare no competing interests. VO, VB, MB, and MB-N are employees from Fiocruz, a federal public institution, which manufactures Vaxzevria in Brazil, through a full technology transfer agreement with AstraZeneca

Ethics Approval Statement: This study analysed de-identified data and was approved by the National Ethics committee (CONEP) (CAAE registration no. 50199321.9.0000.0040).

Suggested Citation

Paixão, Enny S. and Wong, Kerry LM and Alves, Flávia Jôse O. and de Araújo Oliveira, Vinicius and Cerqueira-Silva, Thiago and Júnior, Juracy Bertoldo and Machado, Tales Mota and Júnior, Elzo Pereira Pinto and Boaventura, Viviane and Penna, Gerson O. and Werneck, Guilherme and Rodrigues, Laura C. and Pearce, Neil and Lima Barreto, Mauricio and Barral-Netto, Manoel, Effectiveness of the CoronaVac Vaccine in Prevention of Symptomatic and Progression to Severe COVID-19 in Pregnant Women in Brazil. Available at SSRN: https://ssrn.com/abstract=3962119 or http://dx.doi.org/10.2139/ssrn.3962119

Enny S. Paixão (Contact Author)

London School of Hygiene and Tropical Medicine ( email )

United Kingdom

Kerry LM Wong

London School of Hygiene & Tropical Medicine ( email )

Keppel Street
London, WC1E 7HT
United Kingdom

Flávia Jôse O. Alves

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS) ( email )

Bahia
Brazil

Vinicius De Araújo Oliveira

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS) ( email )

Bahia
Brazil

Thiago Cerqueira-Silva

Oswaldo Cruz Foundation (FIOCRUZ) - LIB and LEITV Laboratories ( email )

Bahia
Brazil

Juracy Bertoldo Júnior

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS) ( email )

Bahia
Brazil

Tales Mota Machado

Universidade de Brasília (UnB) - Tropical Medicine Centre ( email )

Brazil

Elzo Pereira Pinto Júnior

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS)

Bahia
Brazil

Viviane Boaventura

Federal University of Bahia (UFBA) ( email )

Av. Reitor Miguel Calmon, s/n
Vale do Canela
Salvador, Bahia
Brazil

Gerson O. Penna

Universidade de Brasília (UnB) - Tropical Medicine Centre ( email )

Brazil

Guilherme Werneck

Universidade do Estado do Rio de Janeiro (UERJ) - Instituto de Medicina Social ( email )

Rua São Francisco Xavier, 524
Maracanã
Rio de Janeiro, RJ
Brazil

Laura C. Rodrigues

London School of Hygiene & Tropical Medicine ( email )

Keppel Street
London, WC1E 7HT
United Kingdom

Neil Pearce

London School of Hygiene and Tropical Medicine ( email )

United Kingdom

Mauricio Lima Barreto

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS) ( email )

Bahia
Brazil

Manoel Barral-Netto

Oswaldo Cruz Foundation (FIOCRUZ) - Center for Data and Knowledge Integration for Health (CIDACS) ( email )

Bahia
Brazil

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