A virologist at the University of Hong Kong, Jin Dong-yan, said on Monday he expects the opening of the border between Hong Kong and the mainland to bring "manageable risks" to the SAR, as he and the head of a pharmacists' group both called on authorities to consider charging non-residents for Covid vaccinations here.

Officials have said they aim to start allowing more people to flow through the Hong Kong-mainland border by the middle of next month.

"There's definitely risk as many big cities in mainland China are going through a tsunami phase, so they for sure have relatively more infected people," Jin said on an RTHK programme.

He pointed out that Hong Kong could see an increase in cases, as well as demand for vaccinations and antiviral drugs, when more people are allowed to cross the border.

"But I think all the risks are manageable and we should have a bit more confidence in ourselves," the professor in precision medicine added.

Jin said he believes infected incoming travellers will mostly have mild cases of Covid-19 and that PCR tests will be able to screen them out.

On the question of surging demand for drugs and vaccines, meanwhile, he had a proposal.

"As there are sufficient vaccines in the world, perhaps if we save up more and treat it as a business, that won't be a loss for us," the virologist said.

Non-residents who are not studying or working in Hong Kong should be charged for vaccinations, he continued.

Meanwhile, the president of The Society of Hospital Pharmacists, William Chui, also called on the government to charge non-residents for vaccinations, warning that free jabs and treatments could prompt too many to cross the border to access medical services here and burden the local system.

"People from mainland China demand for more symptomatic relief medications," he said. "They may go to Hong Kong to get more medications. At the moment they are looking for medications on the mainland but the supply is very limited."

Chui urged local pharmaceutical companies to quickly boost their production now in view of surging demand to come.

"The Hong Kong government should contact the local drug manufacturers to increase the manufacturing of paracetamol and also other symptomatic relief medications which may be in great demand by the people of the mainland and the people of Hong Kong."