He was citing a study on immunity by the centre and Banphaeo General Hospital in Samut Sakhon. Researchers studied the immunity of people before and after they received two doses of the Chinese vaccine, administered three weeks apart.
“We found that a person’s immunity greatly increased on receiving the vaccine. A month after the second jab, immunity then increased, similar to immunity in patients who had already been infected for 4-8 weeks,” he explained.
“People who received the vaccine have 99.4 per cent immunity against the Covid-19 spike protein, while it was 92.5 per cent for patients who had already been infected,” he said.
Yong said the centre is conducting a long term study on immunity in a bid to predict the chance of Covid-19 infections.
“We already know that patients who have been cured can be infected by Covid-19 again, but the severity is likely to be less than the first time,” he said.
“In the long term, this study will tell us whether it is necessary to administer a third Covid-19 jab and if so then when should it be administered,” he added.