KUAN-YIN LINHSIN-YUN SUNChen Y.-H.Lo Y.-C.SZU-MIN HSIEHWANG-HUEI SHENGYU-CHUNG CHUANGSUNG-CHING PANARISTINE CHENGCHIEN-CHING HUNGCHI-TAI FANGSHAN-CHWEN CHANG2020-09-302020-09-3020201537-6591https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078738750&doi=10.1093%2fcid%2fciz471&partnerID=40&md5=169713c1f5ba1fea4a873b230271f2e5https://scholars.lib.ntu.edu.tw/handle/123456789/515756Background. Beginning from 2015-2016, unprecedented large outbreaks of acute hepatitis A that predominantly affected men who have sex with men (MSM) reemerged across the continents. We assessed the impact of an early initiated hepatitis A virus (HAV) vaccination campaign that targeted MSM living with human immunodeficiency virus (HIV) during the 2015-2017 hepatitis A outbreak in Taiwan. Methods. First, we ascertained the effectiveness of HAV vaccination for MSM living with HIV using a nested case-control study of 1470 persons living with HIV who were initially HAV-seronegative. We then fitted a model of HAV transmission among MSM, risk-structured by HIV status, to the actual epidemic curve of reported acute hepatitis A cases in Taiwan during 2015-2017. Results. Fifty-five cases of acute hepatitis A were matched to 220 controls. Single-dose and 2-dose HAV vaccination provided protection rates of 96.1% and 97.8% among recipient MSM living with HIV, respectively. Model fitting yielded basic reproductive number estimates of 7.26 (MSM living with HIV) and 3.04 (MSM not living with HIV). In a counterfactual scenario without an HAV vaccination campaign, the outbreak would have involved 7153 hepatitis A cases during 2015-2017 in contrast to the 1352 that were observed. We therefore estimated that the HAV vaccination campaign averted 80.7% (sensitivity analysis, 48.8%-92.7%) of acute hepatitis A cases that would otherwise have occurred by the end of 2017. Conclusions. The early initiated HAV vaccination campaign, which targeted MSM living with HIV, very effectively curtailed the 2015-2017 hepatitis A outbreak in Taiwan. ? The Author(s) 2019. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved.[SDGs]SDG3case control study; epidemic; hepatitis A; human; Human immunodeficiency virus infection; male; male homosexuality; preventive health service; sexual and gender minority; Taiwan; vaccination; Case-Control Studies; Disease Outbreaks; Hepatitis A; HIV Infections; Homosexuality, Male; Humans; Immunization Programs; Male; Sexual and Gender Minorities; Taiwan; Vaccinationjournal article10.1093/cid/ciz471311578572-s2.0-85078738750