Postvaccination infections among staff of a tertiary care hospital after vaccination with severe acute respiratory syndrome coronavirus 2 vector and mRNA-based vaccines.
Clin Microbiol Infect
; 28(4): 596-601, 2022 Apr.
Article
in English
| MEDLINE | ID: covidwho-1616427
ABSTRACT
OBJECTIVES:
The identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen or RNA in respiratory specimens ≥14 days after administration of all recommended doses of authorized coronavirus disease 2019 (COVID-19) vaccines is defined as breakthrough infection. In the present investigation, mRNA and vector-based SARS-CoV-2 vaccines were analysed with respect to postvaccination infections in vaccinated hospital employees.METHODS:
A total of 8553 staff members were vaccinated with BNT162b2 (47%) or ChAdOx1-S (53%) between January and May 2021. In a retrospective observational cohort study, incidence of SARS-CoV-2 postvaccination infections was analysed in relation to demographic data, viral load, virus variants, vaccine brand and vaccination status at time of positive PCR test (fully vaccinated ≥14 days since second dose; partially vaccinated >21 days since first, but <14 days after second dose; insufficiently vaccinated <22 days since first dose).RESULTS:
Within the follow-up period, ending on 31 July 2021, person-time at risk-adjusted monthly rates for SARS-CoV-2 postvaccination infections were 0.18% (BNT162b2) and 0.57% (ChAdOx1-S) for insufficiently vaccinated, 0.34% (BNT162b2) and 0.32% (ChAdOx1-S) for partially vaccinated and 0.06% (BNT162b2) and 0.04% (ChAdOx1-S) for fully vaccinated participants. The two vaccine types did not differ with respect to hazard ratios for any of the respective postvaccination infection types. No cases of COVID-19-related hospitalizations or deaths were reported. Genotyping of positive PCR specimens revealed 42 variants of concern B.1.1.7 (Alpha variant; n = 34); B.1.351 (Beta variant; n = 2), B.1.617.2 (Delta variant; n = 6).CONCLUSIONS:
BNT162b2 and ChAdOx1-S are both effective in preventing breakthrough infections; however, it seems important, that all recommended vaccine doses are administered.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
SARS-CoV-2
/
COVID-19
Type of study:
Cohort study
/
Observational study
/
Prognostic study
Topics:
Vaccines
/
Variants
Limits:
Humans
Language:
English
Journal:
Clin Microbiol Infect
Journal subject:
Communicable Diseases
/
Microbiology
Year:
2022
Document Type:
Article
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