Three men were infected with Covid-19 in Singapore. The Thai man was allowed to return to Thailand after healed, but was diagnosed again when he arrived for testing.
The Bangkok Post quoted an official from the Thailand Covid-19 Epidemic Control Center as saying that the three men aged between 43 and 56 had declared to the Thai Embassy in Singapore before boarding the plane before returning home last Friday (4th). , And obtained a health declaration to prove that he is in good health.
It is unclear why they became infected again after they recovered. According to reports, one of the three’s final test results in Singapore or the test results when they arrived in Thailand may have a false positive result.
The Thai authorities are worried about whether this shows that Covid-19 patients are unable to develop immunity after they have recovered, which means that any vaccine may be ineffective.
Last month, on a Scoot flight from Singapore to Tianjin, China, 14 passengers tested positive for Covid-19, 12 of whom were survivors of Covid-19 living in a guest worker dormitory.
The Ministry of Health of Singapore stated that Singapore has strict control over the discharge process of Covid-19 patients, and patients can only be discharged from the hospital if they are in good health 21 days after the diagnosis. In the next few weeks or even months, the recovered person may still have virus fragments in the body. Therefore, the polymerase chain reaction test will still test positive, but there is no evidence that these virus fragments are infectious .