University of Hong Kong microbiologist Ho Pak-leung has criticised the government for spending time on "ineffective lockdowns" rather than targeting places clearly prone to Covid-19 outbreaks, like construction sites.
Ho said on Monday that officials should better prioritise resources, saying if the government decides to lock down an area because sewage tests positive for the coronavirus, the effectiveness of identifying infections would be "the lowest of lows".
Over the weekend, health minister Sophia Chan defended the "ambush lockdowns", saying the positivity rate of 0.08 percent was higher than the voluntary universal testing scheme last September.
But Ho said the government should seal off a building for tests immediately after new cases are found, rather than doing so a week later.
He also said it's strange that no lockdowns have been ordered for construction sites, even though transmission chains have emerged at a number of sites for a month.
Ho noted that officials have never inspected any construction sites, including the airport's third runway project where there has been an outbreak.
"You don't go there to do an epidemiology study, you don't know where and how it was transmitted, then how can you impose measures targetting the problems?" the microbiologist told an RTHK programme.
"But if you only rely on regular testing of the construction workers, this would surely be less effective."
Ho was commenting on a government proposal to require construction workers to take regular Covid tests and present proof of a negative result in order to be able to go to work.
The doctor also criticised the government for exempting mainland drugmaker Sinovac from having to publish data from late-stage clinical trials in a medical journal before its Covid vaccine can be considered for emergency use by SAR experts.
He said publication is one of more than two dozen requirements listed by the World Health Organisation before a vaccine should be cleared for use.