Effectiveness of mRNA-BNT162b2, mRNA-1273, and ChAdOx1 nCoV-19 vaccines against COVID-19 in healthcare workers: an observational study using surveillance data.
Clin Microbiol Infect
; 27(11): 1699.e5-1699.e8, 2021 Nov.
Article
in English
| MEDLINE | ID: covidwho-1506580
ABSTRACT
OBJECTIVES:
Healthcare workers (HCWs) at increased risk of coronavirus disease 2019 (COVID-19) were among the primary targets for vaccine campaigns. We aimed to estimate the protective efficacy of the first three COVID-19 vaccines available in Western Europe.METHODS:
We merged two prospective databases that systematically recorded, in our institution (a) HCWs positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by RT-PCR on nasopharyngeal samples, and (b) HCWs who received at least one dose of COVID-19 vaccine. We excluded HCWs with SARS-CoV-2 infection during the 6 months prior to the study. HCWs were categorized as non-vaccinated if they received no vaccine and until the first injection +13 days, partially vaccinated from the first injection +14 days to the second injection +13 days, and fully vaccinated thereafter.RESULTS:
Of the 8165 HCWs employed in our institution, 360 (4.4%) tested positive for SARS-CoV-2 by RT-PCR during the study period (4th January to 17th May 2021). Incidence was 9.1% (8.2-10.0) in non-vaccinated HCWs, 1.2% (0.7-1.9) after one dose of ChAdOx1 nCoV-19, 1.4% (0.6-2.3) and 0.5% (0.1-1.0) after one and two doses of mRNA BNT162b2, 0.7% (0.1-1.9) and 0% after one and two doses of mRNA-1273 (p < 0.0001). Vaccine effectiveness (Cox model) was estimated at, respectively, 86.2% (76.5-91.0), 38.2% (6.3-59.2), and 49.2% (19.1-68.1) 14 days after the first dose for ChAdOx1 nCoV-19, mRNA-1273, and mRNA-BNT162b2, and 100% (ND) and 94.6% (61.0-99.2) 14 days after the second dose for mRNA-1273 and mRNA-BNT162b2.CONCLUSIONS:
In this real-world study, the observed effectiveness of COVID-19 vaccines in HCWs was in line with the efficacy reported in pivotal randomized trials.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Health Personnel
/
COVID-19 Vaccines
/
COVID-19
Type of study:
Experimental Studies
/
Observational study
/
Prognostic study
/
Randomized controlled trials
Topics:
Vaccines
Limits:
Humans
Language:
English
Journal:
Clin Microbiol Infect
Journal subject:
Communicable Diseases
/
Microbiology
Year:
2021
Document Type:
Article
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