Article in Japanese

Effectiveness of rotavirus vaccine for reducing rotavirus gastroenteritis in hospitalized pediatric patients, analyzed by using the modified Vesikari scoring system

Eri HAYATA¹⁾, Makoto FUJIMORI¹⁾, Syoko HIROSE¹⁾, Hiromichi HAMADA¹⁾, Jyunnichi TAKANASHI¹⁾

Voluntary immunization with rotavirus vaccine began in Japan in 2011. To confirm the clinical impact of the vaccine, this study investigated the background and clinical features of patients hospitalized with rotavirus gastroenteritis before and after rotavirus vaccine coverage was expanded.
We included patients younger than 15 years who were hospitalized for rotavirus gastroenteritis from January 2007 to December 2016. We divided patients into two groups, 2007-2012 and 2013-2016, based on the year that the rotavirus vaccine coverage expanded by more than 50% in Yachiyo, Chiba, where this hospital is located. The backgrounds of the patients and their modified Vesikari Score (MVS) were examined retrospectively. In total, 140 cases from 2007 to 2012 (low-coverage group) and 22 cases from 2013 to 2016 (high-coverage group) were hospitalized; and all of the cases were unvaccinated. The average annual hospitalization decreased by 81.1% from 23.3 persons/year before the rotavirus vaccine coverage was expanded to 4.4 persons/year after it. There were no significant differences in sex and hospitalization period. Median age was 22 and 33 months in the low-coverage and high-coverage group, respectively (p <0.001). In addition, the median MVS value was 16 in the low-coverage group, but significantly reduced to 14 in the high-coverage group (p <0.001). Increased use of rotavirus vaccine in the future may lead to a reduction in the incidence and severity of rotavirus infection in all age groups.

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1) Tokyo Women's Medical University Yachiyo Medical Center

Key words	rotavirus gastroenteritis, rotavirus vaccine, vaccine, modified Vesikari score, pediatric
Received	October 3, 2019
Accepted	January 23, 2020

32 (2)：95─101,2020