tetano
Editor, Senior Moderator
Int J Infect Dis
. 2022 Oct 8;S1201-9712(22)00539-2.
doi: 10.1016/j.ijid.2022.10.001. Online ahead of print.
Effectiveness of mRNA vaccines against SARS-CoV-2 infections during the periods of Delta and Omicron variant predominance in Japan: The VENUS Study
Wataru Mimura[SUP] 1 [/SUP], Chieko Ishiguro[SUP] 2 [/SUP], Megumi Maeda[SUP] 3 [/SUP], Fumiko Murata[SUP] 3 [/SUP], Haruhisa Fukuda[SUP] 3 [/SUP]
Affiliations
Abstract
Objective: We aimed to evaluate coronavirus disease 2019 mRNA vaccine effectiveness during the Delta- and Omicron-predominant periods in Japan.
Methods: We conducted a population-based cohort study among individuals aged 16-64 years during two periods: the Delta-predominant period (July 1 to December 31, 2021) and the Omicron-predominant period (January 1 to March 29, 2022).
Results: Compared with unvaccinated individuals, the effectiveness of a second dose against symptomatic infection were 89.8% (95% confidence interval [CI]: 80.5-94.7%) during the Delta-predominant period and 21.2% (95% CI: 11.0-30.3%) during the Omicron-predominant period. The effectiveness of a third dose against symptomatic infection was 71.8% (95% CI: 60.1-80.1%) during the Omicron-predominant period.
Conclusion: Vaccine effectiveness against symptomatic infection decreased during the Omicron-predominant period but was maintained by a third dose.
Keywords: COVID-19; Japan; mRNA vaccine; population-based cohort study; vaccine effectiveness.
. 2022 Oct 8;S1201-9712(22)00539-2.
doi: 10.1016/j.ijid.2022.10.001. Online ahead of print.
Effectiveness of mRNA vaccines against SARS-CoV-2 infections during the periods of Delta and Omicron variant predominance in Japan: The VENUS Study
Wataru Mimura[SUP] 1 [/SUP], Chieko Ishiguro[SUP] 2 [/SUP], Megumi Maeda[SUP] 3 [/SUP], Fumiko Murata[SUP] 3 [/SUP], Haruhisa Fukuda[SUP] 3 [/SUP]
Affiliations
- PMID: 36220547
- DOI: 10.1016/j.ijid.2022.10.001
Abstract
Objective: We aimed to evaluate coronavirus disease 2019 mRNA vaccine effectiveness during the Delta- and Omicron-predominant periods in Japan.
Methods: We conducted a population-based cohort study among individuals aged 16-64 years during two periods: the Delta-predominant period (July 1 to December 31, 2021) and the Omicron-predominant period (January 1 to March 29, 2022).
Results: Compared with unvaccinated individuals, the effectiveness of a second dose against symptomatic infection were 89.8% (95% confidence interval [CI]: 80.5-94.7%) during the Delta-predominant period and 21.2% (95% CI: 11.0-30.3%) during the Omicron-predominant period. The effectiveness of a third dose against symptomatic infection was 71.8% (95% CI: 60.1-80.1%) during the Omicron-predominant period.
Conclusion: Vaccine effectiveness against symptomatic infection decreased during the Omicron-predominant period but was maintained by a third dose.
Keywords: COVID-19; Japan; mRNA vaccine; population-based cohort study; vaccine effectiveness.