Virologist says blood tests can detect percentage of Thai population infected

A prominent Thai virologist says blood tests should be used to determine the percentage of the population that has been infected with Covid-19. According to a Nation Thailand report, Dr Yong Poovorawan says a blood test can even detect Covid-19 in asymptomatic patients. The head of the Centre of Excellence in Clinical Virology made the statement in a post on his Facebook page yesterday.

Yong explains that Covid infections behave like a pyramid, with 90% of patients at the bottom – meaning they are asymptomatic or have only mild symptoms. This is particularly the case with the now-dominant Omicron variant. However, at the top of the pyramid, are the Covid patients who are severely ill with the virus. These include the elderly and people with underlying health conditions.

According to Yong, a recent study tested the blood of 80 children between the ages of 5 and 11, who were not in a high-risk group and who showed no signs of Covid-19 infection. The tests showed that 5 of the children had been infected but were asymptomatic, having developed natural immunity to the Covid virus spike protein.

Yong says such immunity cannot be replicated by vaccines and that the children are part of a segment of the population that remains asymptomatic, meaning they have to take a blood test to show they’ve been infected with the virus. This means blood tests are the only way to accurately determine how many people in the country have been infected with Covid-19 and gone on to develop natural immunity.

However, he adds that such immunity doesn’t last long, dropping to 25% a year after infection. According to the virologist, blood tests can be used in conjunction with a person’s vaccination history to determine immunity levels.

SOURCE: Nation Thailand