Hong Kong's Centre for Health Protection, part of the Department of Health, said on August 12, 2026, that a hepatitis A transmission chain among men who have sex with men (MSM) is believed to have been interrupted, with the risk to public health now under control. The cluster was announced in mid-March and followed by a drive offering two doses of hepatitis A vaccine free of charge to MSM, launched on March 12. As of July 31, more than 280 MSM had been vaccinated.

During the six-month period from September 2025 to February 2026, Hong Kong recorded 24 hepatitis A infections whose viruses were genetically identical, involving 22 males and two females; over 60 per cent of the male patients identified themselves as MSM. Reported infections fell to five in June and two in July, compared with 15 in January. The CHP said patients in the past two months ranged in age from 21 to 83, three of them identified as MSM, and none of the cases recorded after June carried the virus genetically identical to that cluster.

The CHP said the free vaccination initiative for MSM would end on September 12, with its online booking platform accepting MSM appointments only until September 11. It said it would contact people who received a first dose but could not complete the two-dose series by that date about second-dose arrangements. The centre noted that hepatitis A can spread through contaminated food, water or hands, and through high-risk sexual contact, with an incubation period usually of 14 to 28 days.