Local expert says herd immunity impossible as Delta variant can transmit from 1 person to 5-8 others


11th September 2021 – (Hong Kong) David Hui, Chair Professor of Respiratory System of CUHK, who is also a government expert consultant, said on a radio program this morning (11th) that the concept of “herd immunity” should be relabelled as “protective barrier”.

When the COVID-19 first appeared, the virus transmission rate was about 1 to 3, but the Delta variant virus has been rampant in recent months, the virus S protein has changed, and it is easier to invade the human body, which increases the amount of virus in patients and the virus transmission rate to 1 person to 5 to 8 people.

He also pointed out that although there is still a chance of infection after vaccination, it can reduce the risk of severe illness or death, so it is still worth receiving vaccine.

Regarding the Hong Kong government’s claim that it has invited mainland experts to discuss border reopening issues, Hui said that the expert consultant did not participate in the discussion of the arrangements between China and Hong Kong. It is believed that the opinions of public health experts from the Department of Health are mainly provided. He believes that the conditions for two-way border reopening with quarantine exemptions between the two places include the continuous “zero diagnosis” in Hong Kong and the need to further increase the COVID-19 vaccination rate, especially among the elderly.