Your browser doesn't support javascript.
loading
Effectiveness of mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections during the Delta variant epidemic in Japan: Vaccine Effectiveness Real-time Surveillance for SARS-CoV-2 (VERSUS)
Haruka Maeda; Nobuo Saito; Ataru Igarashi; Masayuki Ishida; Kazuya Suami; Ai Yagiuchi; Yuya Kimura; Masaru Komino; Hiromi Arai; Toru Morikawa; Iori Motohashi; Rei Miyazawa; Tetsu Moriyama; Hiroshi Kamura; Mayumi Terada; Osamu Kuwamitsu; Tomoichiro Hayakawa; Eiichiro Sando; Yasuji Ohara; Osamu Teshigawara; Motoi Suzuki; Konosuke Morimoto.
Affiliation
  • Haruka Maeda; Nagasaki University
  • Nobuo Saito; Department of Microbiology, Faculty of Medicine, Oita University, Oita, Japan
  • Ataru Igarashi; Unit of Public Health and Preventive Medicine, Yokohama City University School of Medicine, Kanagawa, Japan; Department of Health Economics and Outcomes Researc
  • Masayuki Ishida; Chikamori Hospital, Kochi, Japan
  • Kazuya Suami; Nagoya Ekisaikai Hospital, Aichi, Japan
  • Ai Yagiuchi; Nagoya Ekisaikai Hospital, Aichi, Japan
  • Yuya Kimura; Saiseikai Kurihashi Hospital, Saitama, Japan
  • Masaru Komino; Saiseikai Kurihashi Hospital, Saitama, Japan
  • Hiromi Arai; Saiseikai Kurihashi Hospital, Saitama, Japan
  • Toru Morikawa; Nara City Hospital, Nara, Japan
  • Iori Motohashi; Kawasaki Municipal Tama Hospital, Kanagawa, Japan
  • Rei Miyazawa; Kawasaki Municipal Tama Hospital, Kanagawa, Japan
  • Tetsu Moriyama; Moriyama Memorial Hospital, Tokyo, Japan
  • Hiroshi Kamura; Loco Clinic Nakameguro, Tokyo, Japan
  • Mayumi Terada; Nijigaoka Hospital, Nagasaki, Japan
  • Osamu Kuwamitsu; Gohongi Clinic, Tokyo, Japan
  • Tomoichiro Hayakawa; Hayakawa Internal Medicine Clinic, Fukuoka, Japan
  • Eiichiro Sando; Kita-Fukushima Medical Center, Fukushima, Japan; Fukushima Medical University, Fukushima, Japan
  • Yasuji Ohara; Takagi Hospital, Aichi, Japan
  • Osamu Teshigawara; Mizuho Street Clinic, Aichi, Japan
  • Motoi Suzuki; Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan
  • Konosuke Morimoto; Department of Respiratory Infections, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
Preprint in English | medRxiv | ID: ppmedrxiv-22269394
ABSTRACT
BackgroundAlthough high vaccine effectiveness of messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccines was reported in studies in several countries, data is limited from Asian countries, especially against the Delta (B.1.617.2) variant. MethodsWe conducted a multicenter test-negative case-control study in patients aged [≥]16 visiting hospitals or clinics with signs or symptoms consistent with COVID-19 from July 1 to September 30, 2021, when the Delta variant was dominant ([≥]90% of severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] infections) nationwide in Japan. Vaccine effectiveness of BNT162b2 or mRNA-1273 against symptomatic SARS-CoV-2 infections was evaluated. Waning immunity among patients aged 16 to 64 was also assessed. ResultsWe enrolled 1936 patients, including 396 test-positive cases and 1540 test-negative controls for SARS-CoV-2. The median age was 49 years, 53.4% were male, and 34.0% had underlying medical conditions. Full vaccination (receiving two doses [≥]14 days before symptom onset) was received by 6.6% of cases and 38.8% of controls. Vaccine effectiveness of full vaccination against symptomatic SARS-CoV-2 infections was 88.7% (95% confidence interval [CI], 78.8-93.9) among patients aged 16 to 64 and 90.3% (95% CI, 73.6-96.4) among patients aged [≥]65. Among patients aged 16 to 64, vaccine effectiveness within one to three months after full vaccination was 91.8% (95% CI, 80.3-96.6), and was 86.4% (95% CI, 56.9-95.7) within four to six months. ConclusionsmRNA COVID-19 vaccines had high effectiveness against symptomatic SARS-CoV-2 infections in Japan during July 1 to September 30, 2021, when the Delta variant was dominant nationwide.
License
cc_by_nd
Full text: Available Collection: Preprints Database: medRxiv Type of study: Experimental_studies / Observational study Language: English Year: 2022 Document type: Preprint
Full text: Available Collection: Preprints Database: medRxiv Type of study: Experimental_studies / Observational study Language: English Year: 2022 Document type: Preprint
...