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: Breakthrough infection; Hospital employees; Postvaccination infection; Severe acute respiratory syndrome coronavirus 2; Vector-based vaccine; mRNA-based vaccine.
【저자키워드】 severe acute respiratory syndrome coronavirus 2, Breakthrough infection, Hospital employees, Postvaccination infection, Vector-based vaccine, mRNA-based vaccine., 【초록키워드】 COVID-19, coronavirus disease, severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, Coronavirus disease 2019, Vaccine, coronavirus, vaccination, vaccine doses, Hospitalization, B.1.351, hospital, variant, Infection, Delta, B.1.617.2, severe acute respiratory syndrome Coronavirus, delta variant, SARS-CoV-2 vaccine, cohort study, Antigen, RNA, vaccine dose, BNT162b2, Viral load, B.1.1.7, mRNA, death, breakthrough infections, Beta, Breakthrough infection, virus variants, Alpha variant, incidence, Beta variant, ChAdOx1, ChAdOx1-S, retrospective, administration, dose, Vector-based vaccine, Vaccination Status, Observational cohort study, acute respiratory syndrome, Participants, follow-up period, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, second dose, hazard ratio, first dose, demographic data, specimen, positive PCR test, hazard ratios, positive PCR, retrospective observational cohort study, mRNA-based vaccine, postvaccination, Administered, effective, defined, not differ, respiratory specimen, reported, analysed, 【제목키워드】 coronavirus, vaccination, hospital, Infection, Care, acute respiratory syndrome,