4.7 Article

Effectiveness of messenger RNA vaccines against infection with SARS-CoV-2 during the periods of Delta and Omicron variant predominance in Japan: the Vaccine Effectiveness, Networking, and Universal Safety (VENUS) study

Journal

INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES
Volume 125, Issue -, Pages 58-60

Publisher

ELSEVIER SCI LTD
DOI: 10.1016/j.ijid.2022.10.001

Keywords

COVID-19; Messenger RNA vaccine; Vaccine effectiveness; Population -based cohort study; Japan

Funding

  1. Japan Agency for Med- ical Research and Development (AMED)
  2. [JP21nf0101635]

Ask authors/readers for more resources

This study aimed to evaluate the effectiveness of the COVID-19 mRNA vaccine during the Delta and Omicron predominant periods in Japan. The results showed a decrease in vaccine effectiveness against symptomatic infection during the Omicron predominant period, but this effectiveness was maintained by a third dose.
Objectives: We aimed to evaluate COVID-19 messenger RNA 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-December 31, 2021) and the Omicron-predominant period (January 1-March 29, 2022).Results: When comparing individuals who were vaccinated with those who were unvaccinated, the ef-fectiveness of a second dose against symptomatic infection was 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.(c) 2022 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available