Adverse Events after the Introduction of Quadrivalent Influenza Vaccine in Comparison with AH1pdm Vaccine (2009) in Japan

• Published in: YAKUGAKU ZASSHI Vol. 139; no. 3; pp. 469 - 474
• Main Authors: Yamazaki, Shingo, Fujiwara, Mariko, Inoue, Chikako, Watanabe, Masaharu, Takayanagi, Shin, Taniguchi, Toshibumi, Watanabe, Akira, Ishiwada, Naruhiko, Igari, Hidetoshi
• Format: Journal Article
• Language: Japanese
• Published: Japan The Pharmaceutical Society of Japan 01.03.2019; Pharmaceutical Society of Japan
• Subjects: adverse event; AH1pdm vaccine; quadrivalent influenza vaccine; quadrivalent influenza vaccine; adverse event; AH1pdm vaccine
• ISSN: 0031-6903; 1347-5231
• DOI: 10.1248/yakushi.18-00160

Inactivated quadrivalent influenza vaccine (IIV4) has been used as seasonal influenza vaccine since 2016 in Japan. This study examined the safety of IIV4 in comparison with the AH1pdm monovalent vaccine used for novel influenza in 2009. Questionnaire surveillance associated with adverse events (AEs) was conducted at Chiba University Hospital, Japan. After being vaccinated, all health care workers (HCWs) were given a daily AEs check sheet on which they recorded solicited events, the same surveillance program used after AH1pdm vaccination in 2009. The frequency of injection site AEs with IIV4 was significantly higher than with the monovalent vaccine, but there was no significant difference with systemic AEs. Injection site and systemic AEs were reported as 83.7% and 25.5%, respectively, with IIV4. The grades of AE, mild, moderate and severe, were 67.2%, 16.4% and 0.1% with IIV4, respectively, indicating that almost all of the AEs reported with IIV4 were mild or moderate. Systemic AEs with IIV4 and monovalent vaccine were reported to be 25.5% and 23.1%, respectively, with the difference not being significant. The grade of AEs with IIV4, mild, moderate and severe, was 19.1%, 5.6% and 0.9%, respectively. The ratio of HCWs reporting AEs peaked at around 80% on day 1, then decreasing to less than 5% by day 7. AEs with IIV4 were reported more frequently compared with the AH1pdm monovalent vaccine. However, in consideration of the grade and duration of AEs, IIV4 was a well-tolerated, safe vaccine.