Effectiveness of BA.1- and BA.4/BA.5-containing bivalent COVID-19 mRNA vaccines against symptomatic SARS-CoV-2 infection during the BA.5-dominant period in Japan
Takeshi Arashiro, Yuzo Arima, Jin Kuramochi, Hirokazu Muraoka, Akihiro Sato, Kumi Chubachi, Atsushi Yanai, Hiroko Arioka, Yuki Uehara, Genei Ihara, Yasuyuki Kato, Naoki Yanagisawa, Akihiro Ueda, Hideaki Kato, Hideaki Oka, Yusuke Nishida, Yuki Nidaira, Takahiro Asami, Torahiko Jinta, Akira Nakamura, Kunihiro Oba, Daisuke Taniyama, Kei Yamamoto, Katsushi Tanaka, Kankuro Ueshima, Tetsuji Fuwa, Ashley Stucky, Tadaki Suzuki, Chris Smith, Martin L. Hibberd, Koya Ariyoshi, Motoi Suzuki
Abstract
In this multicenter, prospective, test-negative, case-control study in Japan, the effectiveness of both BA.1-containing and BA.4/BA.5-containing bivalent coronavirus disease 2019 mRNA vaccines against symptomatic infection during the BA.5-dominant period was high compared with no vaccination (65% and 76%) and moderate compared with monovalent vaccines administered over half a year earlier (46% combined).