Starting in October, some cities in Northeast China's Heilongjiang province have begun offering COVID-19 booster shots to targeted groups to strengthen their immunity to the virus, Heilongjiang Daily reported.

The third vaccine doses will be made available for people aged over 18 who have already been fully vaccinated for at least six months, according to local governments of the cities including Harbin, Qiqihar, Jiamusi, Mudanjiang, Jixi and Heihe.

People intending to get an additional shot will be given the same vaccine made by the same company. If supplies of a particular vaccine run short, other vaccines of the same type but created by a different company can be used as an alternative, local authorities said.

Harbin, the province's capital city, started to carry out the work on Sunday.

"Everything is in order during these days' vaccination service at our center," said Liang Guangyun, director of the Kang'an Community Health Center in Daoli district. "We prepared enough storage of vaccines and residents can come to the center directly to get vaccinated."