Efficacy of Homologous and Heterologous Vaccine Applications on SARS-CoV-2 Omicron Variant: Cohort of Manisa Celal Bayar University Healthcare Workers

This study was aimed to determine the efficacy of homologous (only CoronaVac or only Pfizer-BioNTech) and heterologous (CoronaVac and Pfizer-BioNTech) vaccines during the period when the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) Omicron variant was dominant in Türkiye. Coronavirus disease-2019 (COVID-2019) infection was confirmed by reverse transcriptase polymerase chain reaction and data on vaccination status against COVID-19 were evaluated during the period of 15 January 2022-1 May 2022 when the SARS-CoV-2 Omicron variant was dominant among 1854 employees followed in the SARS-CoV-2 Vaccine Cohort of Manisa Celal Bayar University (MCBU) Hospital Health Workers. Two separate reference groups were used in the evaluation of vaccine efficacy: those who were never vaccinated and those who received only two doses of CoronaVac. The efficacy of homologous and heterologous vaccine models was evaluated with relative risks and attributable risk percentages. MS Excel, SPSS 23.0 and STATA 14.1 package programs were used for statistical analysis. The mean age of the participants was 36.6 ± 10.0. During the period from January 15th to May 1st 2022, 372 hospital workers were infected with COVID-19. Taking the never vaccinated as the reference group, the most effective model was found to be only the three or more doses of the Pfizer-BioNTech primary vaccination model (85.8%, 95% CI= 40.7-96.6). Models consisting of a single dose of CoronaVac (6.5%, 95% CI= -56.3-44.2) or...
Source: Mikrobiyoloji Bulteni - Category: Microbiology Authors: Source Type: research