Hong Kong vaccine experts do not rule out fourth jab for some residentsPeople wear costumes as they walk inside a discount chain store on Halloween in Hong Kong on Oct 31, 2021. (Reuters photo)HONG KONG: Hong Kong government vaccine experts have said they do not rule out the possibility of a fourth Covid-19 jab for residents, with the city rolling out third shots under its booster programme next week. Hong Kong will start offering booster shots to the elderly and those under high-risk groups from next Thursday. About 24,500 people had signed up online for the third vaccine dose as of 8pm on Friday, the first day bookings became available. "For those who had received the Sinovac vaccine, they may need to take the booster shot earlier, but we still need to prioritise in the end."