Dataset Information

Effectiveness of two COVID-19 vaccines (viral vector and inactivated viral vaccine) against SARS-CoV-2 infection in a cohort of healthcare workers.

ABSTRACT:

Objectives

We aimed to investigate real-world vaccine effectiveness (VE) for Oxford-AstraZeneca (ChAdOx1) and CoronaVac against laboratory-confirmed COVID-19 infection among healthcare workers (HCWs).

Methods

We conducted a retrospective cohort study among HCWs (aged ≥18 years) working in a private healthcare system in Brazil between January 1, 2021 and August 3, 2021. To assess VE, we calculated VE=1-RR (rate ratio), with RR determined by adjusting Poisson models with the occurrence of COVID-19 infection as the outcome, and the vaccination status as the main exploratory variable. We used the logarithmic link function and simple models adjusting for sex, age and job types.

Results

13,813 HCWs met the inclusion criteria for this analysis. 6,385 (46.2%) received the CoronaVacvaccine, 5,916 (42.8%) received the ChAdOx1 vaccine, and 1,512 (11.0%) were not vaccinated. Overall, COVID-19 infection cases happened in 6% of unvaccinated HCWs, 3% of HCWs receiving two doses of CoronaVacvaccine, and 0.7% of HCWs receiving two doses of ChAdOx1 vaccine (p-value< 0.001). In the adjusted analyses, the estimated VE was 51.3% for CoronaVac, and 88.1% for ChAdOx1 vaccine. Both vaccines reduced the number of hospitalizations, the length of hospital stay, and the need of mechanical ventilation. Nineteen SARSCoV-2 samples from nineteen HCWs were screened for mutations of interest. Eighteen out of nineteen of those samples were Gamma SARS-CoV-2 variant.

Conclusions

While both COVID-19 vaccines (viral vector and inactivated virus) can significantly prevent COVID-19 infection among HCWs, CoronaVac was much less effective. The COVID-19 vaccines were also effective even against a dominant Gamma variant.

SUBMITTER: Marra AR

PROVIDER: S-EPMC9002147 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature

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Publications

Effectiveness of two coronavirus disease 2019 (COVID-19) vaccines (viral vector and inactivated viral vaccine) against severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection in a cohort of healthcare workers.

Marra Alexandre R AR Miraglia João Luiz JL Malheiros Daniel Tavares DT Guozhang Yang Y Teich Vanessa Damazio VD da Silva Victor Elivane E Pinho João Renato Rebello JRR Cypriano Adriana A Vieira Laura Wanderly LW Polonio Miria M Ornelas Rafael Herrera RH de Oliveira Solange Miranda SM Borges Junior Flavio Araujo FA Shibata Audrey Rie Ogawa ARO Schettino Guilherme de Paula Pinto GPP de Oliveira Ketti Gleyzer KG Ferraz Santana Rúbia Anita RA de Mello Malta Fernanda F Amgarten Deyvid D Boechat Ana Laura AL Trecenti Noelly Maria Zimpel NMZ Kobayashi Takaaki T Salinas Jorge L JL Edmond Michael B MB Rizzo Luiz Vicente LV

Infection control and hospital epidemiology 20220330 1

<h4>Objective</h4>We investigated real-world vaccine effectiveness for Oxford-AstraZeneca (ChAdOx1) and CoronaVac against laboratory-confirmed severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among healthcare workers (HCWs).<h4>Methods</h4>We conducted a retrospective cohort study among HCWs (aged ≥18 years) working in a private healthcare system in Brazil between January 1, 2021 and August 3, 2021, to assess vaccine effectiveness. We calculated vaccine effectiveness as 1 - ra ...[more]

PMID: 35351217

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