Duration of protection of CoronaVac plus heterologous BNT162b2 booster in the Omicron period in Brazil.
Nat Commun
; 13(1): 4154, 2022 07 18.
Article
in English
| MEDLINE | ID: covidwho-1937434
ABSTRACT
To date, no information has been published on the effectiveness of inactivated whole-virus COVID-19 vaccines plus heterologous booster against symptomatic infection and severe outcomes (hospitalization or death) during the dominance of the SARS-CoV-2 Omicron variant period. We evaluated the vaccine effectiveness (VE) of CoronaVac plus BNT162b2 booster during the period of dominance of the Omicron variant in Brazil (January to April 2022). Using a test-negative design, we analysed data for 2,471,576 individuals tested during the Omicron variant's dominant period using a nationally linked database from Brazil. Compared to unvaccinated, vaccinees maintained protection against severe outcomes, with an estimated VE of 84.1% (95% CI83.2-84.9) at more than 120 days after BNT162b2 booster. Furthermore, while we detected a high level of protection against severe outcomes for individuals up to 79 years old, waning was observed for individuals aged ≥80 years, with VE decreasing from 81.3% (95% CI77.9-84.2) at 31-60 days to 72.9% (95% CI70.6-75.1) at 120 days or more after the booster dose. However, no significant protection against symptomatic infection was observed at this time period. In conclusion, except for individuals aged ≥80 years, CoronaVac plus a BNT162b2 booster dose offered high and durable protection against severe outcomes due to Omicron.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
COVID-19 Vaccines
/
COVID-19
Type of study:
Experimental Studies
/
Observational study
Topics:
Vaccines
/
Variants
Limits:
Humans
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Nat Commun
Journal subject:
Biology
/
Science
Year:
2022
Document Type:
Article
Affiliation country:
S41467-022-31839-7
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