Dataset Information

Effectiveness of mRNA-BNT162b2, mRNA-1273, and ChAdOx1 nCoV-19 vaccines against COVID-19 in healthcare workers: an observational study using surveillance data.

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.

SUBMITTER: Paris C

PROVIDER: S-EPMC8275842 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Background Both BNT162b2 (Pfizer–BioNTech) and ChAdOx1 nCoV-19 (Oxford–AstraZeneca) vaccines have shown high efficacy against COVID-19 in randomized controlled trials. However, their comparative effectiveness against COVID-19 is unclear in the real world. We evaluated the comparative effectiveness of the BNT162b2 and ChAdOx1 nCoV-19 vaccines against COVID-19 in the UK general population. Methods We emulated a target trial using IQVIA Medical Research Database (IMRD), an electronic primary care database from the UK (2021). We included 1,311,075 participants, consisting of 637,549 men and 673,526 women age≥18 years, who received vaccination with BNT162b2 or ChAdOx1 nCoV-19 between January 1 and August 31, 2021. The outcomes consisted of confirmed diagnosis of SARS-CoV-2 infection, hospitalisation for COVID-19 and death from COVID-19 in the IMRD. We performed a cox-proportional hazard model to compare the risk of each outcome variable between the two vaccines adjusting for potential confounders with time-stratified overlap weighting of propensity score (PS). Results During a mean of 6.7 months of follow-up, 20,070 confirmed SARS-CoV-2 infection occurred in individuals who received BNT162b2 vaccine (PS weighted incidence rate: 3.65 per 1000 person-months), and 31,611 SARS-CoV-2 infection occurred in those who received ChAdOx1 nCoV-19 vaccine (PS weighted incidence rate: 5.25 per 1000 person-months). The time-stratified PS weighted rate difference of SARS-CoV-2 infection for BNT162b2 group vs. ChAdOx1 nCoV-19 group was -1.60 per 1000 person-months (95% confidence interval [CI]: -1.76 to -1.43 per 1000 person-months), and the hazard ratio was 0.69 (95% CI: 0.68 to 0.71). The results were similar across the stratum of sex, age (<65 and ≥65 years), and study periods (i.e., alpha-variant predominance period and delta-variant predominance period). The PS weighted incidence of hospitalisation for COVID-19 was also lower in the BNT162b2 vaccine group than that in the ChAdOx1 vaccine group (RD: -0.09, 95%CI: -0.13 to -0.05 per 1000 person-months; HR: 0.65, 95%CI: 0.57 to 0.74). No significant difference in the risk of death from COVID-19 was observed between the two comparison groups. Conclusions In this population-based study, the BNT162b2 vaccine appears to be more efficacious than the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2 infection and hospitalisation for COVID-19 but not death from COVID-19. Supplementary Information The online version contains supplementary material available at 10.1186/s12916-023-02795-w.