Epidemiologist Benjamin Cowling of the University of Hong Kong (HKU) said on Tuesday he believed the overall level of immunity to Covid-19 in Hong Kong was significantly higher than official figures suggest.
He was commenting on a new study that found strong antibody responses in recovered Covid patients who then receive a vaccine.
Researchers from HKU and China University had confirmed that Covid vaccines were more effective when given to people who have recovered from the coronavirus, compared to those who have never been infected.
Cowling told RTHK Covid update program is good news.
“We consider infections to act as natural reminders and can replace the dose. What we have in Hong Kong across the population in the past three months…two-thirds of the population have had a natural callback,” he said. .
“Many of them have not been documented because we only have about 1.2 million confirmed cases. We believe there have been more than four million infections because not all infections are confirmed,” he explained.
“That means the level of immunity we currently have in our population is higher than just reflected in vaccination coverage and the number of confirmed cases.”
One of the study’s lead researchers, Professor David Hui of China University, also noted that people who received a BioNTech jab after an infection had “a very high level” of antibodies – around 144 units. , compared with 95 units among people who received three vaccine injections but were not infected.
He said recovered patients should therefore also consider getting bitten.
“After they are infected, people’s antibody level drops gradually. It will drop to a very low level after six months and they might get infected again. They should get the vaccine three months after their infection to boost their immunity levels. “, did he declare.