tetano
Editor, Senior Moderator
Open Forum Infect Dis
. 2023 Apr 19;10(6)
fad209.
doi: 10.1093/ofid/ofad209. eCollection 2023 Jun. Effectiveness of the Coronavirus Disease 2019 Bivalent Vaccine
Nabin K Shrestha[SUP] 1 [/SUP], Patrick C Burke[SUP] 2 [/SUP], Amy S Nowacki[SUP] 3 [/SUP], James F Simon[SUP] 4 [/SUP], Amanda Hagen[SUP] 5 [/SUP], Steven M Gordon[SUP] 1 [/SUP]
Affiliations
Background: The purpose of this study was to evaluate whether a bivalent coronavirus disease 2019 (COVID-19) vaccine protects against COVID-19.
Methods: The study included employees of Cleveland Clinic in employment when the bivalent COVID-19 vaccine first became available. Cumulative incidence of COVID-19 over the following 26 weeks was examined. Protection provided by vaccination (analyzed as a time-dependent covariate) was evaluated using Cox proportional hazards regression, with change in dominant circulating lineages over time accounted for by time-dependent coefficients. The analysis was adjusted for the pandemic phase when the last prior COVID-19 episode occurred and the number of prior vaccine doses.
Results: Among 51 017 employees, COVID-19 occurred in 4424 (8.7%) during the study. In multivariable analysis, the bivalent-vaccinated state was associated with lower risk of COVID-19 during the BA.4/5-dominant (hazard ratio, 0.71 [95% confidence interval, .63-79]) and the BQ-dominant (0.80 [.69-.94]) phases, but decreased risk was not found during the XBB-dominant phase (0.96 [.82-.1.12]). The estimated vaccine effectiveness was 29% (95% confidence interval, 21%-37%), 20% (6%-31%), and 4% (-12% to 18%), during the BA.4/5-, BQ-, and XBB-dominant phases, respectively. The risk of COVID-19 also increased with time since the most recent prior COVID-19 episode and with the number of vaccine doses previously received.
Conclusions: The bivalent COVID-19 vaccine given to working-aged adults afforded modest protection overall against COVID-19 while the BA.4/5 lineages were the dominant circulating strains, afforded less protection when the BQ lineages were dominant, and effectiveness was not demonstrated when the XBB lineages were dominant.
Keywords: COVID-19; SARS-CoV-2; bivalent vaccine; effectiveness; vaccines.
. 2023 Apr 19;10(6)
fad209.doi: 10.1093/ofid/ofad209. eCollection 2023 Jun. Effectiveness of the Coronavirus Disease 2019 Bivalent Vaccine
Nabin K Shrestha[SUP] 1 [/SUP], Patrick C Burke[SUP] 2 [/SUP], Amy S Nowacki[SUP] 3 [/SUP], James F Simon[SUP] 4 [/SUP], Amanda Hagen[SUP] 5 [/SUP], Steven M Gordon[SUP] 1 [/SUP]
Affiliations
- PMID: 37274183
- PMCID: PMC10234376
- DOI: 10.1093/ofid/ofad209
Background: The purpose of this study was to evaluate whether a bivalent coronavirus disease 2019 (COVID-19) vaccine protects against COVID-19.
Methods: The study included employees of Cleveland Clinic in employment when the bivalent COVID-19 vaccine first became available. Cumulative incidence of COVID-19 over the following 26 weeks was examined. Protection provided by vaccination (analyzed as a time-dependent covariate) was evaluated using Cox proportional hazards regression, with change in dominant circulating lineages over time accounted for by time-dependent coefficients. The analysis was adjusted for the pandemic phase when the last prior COVID-19 episode occurred and the number of prior vaccine doses.
Results: Among 51 017 employees, COVID-19 occurred in 4424 (8.7%) during the study. In multivariable analysis, the bivalent-vaccinated state was associated with lower risk of COVID-19 during the BA.4/5-dominant (hazard ratio, 0.71 [95% confidence interval, .63-79]) and the BQ-dominant (0.80 [.69-.94]) phases, but decreased risk was not found during the XBB-dominant phase (0.96 [.82-.1.12]). The estimated vaccine effectiveness was 29% (95% confidence interval, 21%-37%), 20% (6%-31%), and 4% (-12% to 18%), during the BA.4/5-, BQ-, and XBB-dominant phases, respectively. The risk of COVID-19 also increased with time since the most recent prior COVID-19 episode and with the number of vaccine doses previously received.
Conclusions: The bivalent COVID-19 vaccine given to working-aged adults afforded modest protection overall against COVID-19 while the BA.4/5 lineages were the dominant circulating strains, afforded less protection when the BQ lineages were dominant, and effectiveness was not demonstrated when the XBB lineages were dominant.
Keywords: COVID-19; SARS-CoV-2; bivalent vaccine; effectiveness; vaccines.