A government adviser on Covid suggested on Monday that the cost-effectiveness and coverage of Covid booster vaccinations should be assessed in the long term as infections become milder.

The Scientific Committee on Vaccine Preventable Diseases currently recommends a booster shot every six months for high-risk groups such as the over-50s and those with underlying health conditions. They can receive the booster free of charge.

The committee's chairman, Professor Lau Yu-lung, said there has been a slight increase in Covid cases recently, but this is not a cause for concern.

"From a public health perspective, we really need some kind of a study to assess the cost-effectiveness... it might not be necessary to administer as in the past, the whole scale of approach for a lot of people," he said.

"Recently, because of the upsurge of all the monitoring indices, as well as you can just learn from your friends and families who got infected, most of them are really very mild... Indeed every successive infection will be milder than the previous infection until you won't even notice it."