That is why people may be infected with coronavirus a second time

In China, coronavirus was diagnosed for the second time in a number of patients. It was previously said that people became immune to the virus after the initial infection. Then why do they get sick again?

A woman in Japan, who works as a tour guide, heard for the second time yesterday that she was infected with the coronavirus. On 29 January, the first time the virus was diagnosed in women. Five days later, she tested negative again and was allowed to leave the hospital. Earlier it was reported that Chinese patients discharged from the hospital again tested positive for the coronavirus.

No antibodies or ‘biphasic’ course

Why some patients get sick again due to the virus is not yet defined. According to experts, recovering patients may not have built up enough antibodies, however, and therefore have not developed immunity to the coronavirus.

The virus could also be ‘biphasic’, causing disease symptoms to occur in two separate periods. A patient can be sick for a few days, then be ‘cured’, and then relapse.

Healed too early

Another cause for the ‘second contamination’ probably tests errors. For example, a patient returned to the hospital on 21 February, when a later test returned positive. The patient was allowed to leave the hospital after a nose and throat decrease, but doctors only found the virus in the lower airways during a third test.

In addition, some patients who are healthy enough to leave the hospital may be carriers of the virus for a while, according to a study by the American Medical Association, which examined four patients in the Chinese epicenter of the virus, Wuhan.

Not contagious

Song Tie, vice president of a local health organization in a province in China, said during a press briefing that 14 percent of patients in the region tested positive again, despite being allowed to leave the hospital. Fortunately, the patients did not seem to infect anyone else. He concluded that infected persons produce antibodies and are no longer contagious.

So far in China, 36,117 patients have been declared cured and have been allowed to leave hospitals, according to official data. That is about 46 percent of the total number of infections in mainland China. More than 2,700 people have died, and the rest have not yet recovered.