A government adviser on the pandemic, David Hui, said on Saturday that there's no need to tighten social distancing rules right now, despite an increase in the number of Covid infections.

The daily caseload has been rising steadily, with reported infections exceeding four thousand a day since July 21.

The Chinese University professor noted that the increase is within expectations, adding that more people in Hong Kong are now vaccinated, and quite a large portion of the population had generated antibodies from previous infections.

"With this protective community in the background, there's really no need to tighten social distancing measures. We need to balance recovery of the economy and normalise the daily living, versus infection control," Hui told reporters after attending a Commercial Radio programme.

"At the moment we're mainly seeing mild cases, the number of severe and critical cases is actually quite low compared to March this year," he added, referring to the peak of the Omicron wave.

The professor added that relatively few of the patients admitted to hospital are in intensive care, and the key right now is to push up the vaccination rate.

Hui said government vaccine advisors would soon meet to discuss allowing those aged three and under to be vaccinated.

He said in the event they agree to vaccination for younger children, it remains to be seen whether jab manufacturers will apply to lower the age threshold, and whether they would import smaller doses.

Hui noted that there are difficulties for diluting BioNTech doses into smaller portions for young children.

Currently in Hong Kong, children aged three and above can receive Sinovac injections, while the minimum age for BioNTech vaccines is five.