Effectiveness of an inactivated Covid-19 vaccine with homologous and heterologous boosters against Omicron in Brazil
- Ranzani, Otavio
- Hitchings, Matt D.T.
- Melo, Rosana Leite de
- França, Giovanny V.A. de
- Fernandes, Cássia de Fátima R.
- Lind, Margaret L.
- Torres, Mario Sergio Scaramuzzini
- Tsuha, Daniel Enrique
- David, Leticia C.S.
- Said, Rodrigo F.C.
- Almiron, Maria
- Oliveira, Roberto D. de
- Cummings, Derek A.T.
- Dean, Natalie E.
- Andrews, Jason R.
- Ko, Albert I.
- Croda, Julio
DOIAbstract
The effectiveness of inactivated vaccines (VE) against symptomatic and severe COVID-19 caused by omicron is unknown. We conducted a nationwide, test-negative, case-control study to estimate VE for homologous and heterologous (BNT162b2) booster doses in adults who received two doses of CoronaVac in Brazil in the Omicron context. Analyzing 1,386,544 matched-pairs, VE against symptomatic disease was 8.6% (95% CI, 5.6-11.5) and 56.8% (95% CI, 56.3-57.3) in the period 8-59 days after receiving a homologous and heterologous booster, respectively. During the same interval, VE against severe Covid-19 was 73.6% (95% CI, 63.9-80.7) and 86.0% (95% CI, 84.5-87.4) after receiving a homologous and heterologous booster, respectively. Waning against severe...
Add to ORKG