Patients declared cured of Covid-19 and tested positive for the disease again are actually expelling dead lung cells, the World Health Organization said on Wednesday. (WHO). The hypothesis of a possible short-term reinfection is therefore ruled out for the moment.
As South Korea was gaining the upper hand in the Covid-19 epidemic, 116 new cases declared positive after recovery a few weeks ago had left the puzzled researchers. Same cases in China and Japan, where the authorities reported that several people cured of the infection had nevertheless tested positive a second time. The following question then inevitably arose:can we catch this coronavirus twice?
Many, upon the announcement of these results, tended to quickly dismiss the idea of a possible reinfection, favoring more the thesis of the presence of "traces of virus not completely eliminated". Like Florian Krammer, virologist at the Icahn School of Medicine at Mount Sinai in New York (USA).
“I'm not saying reinfection is impossible but in this short time it's unlikely “, he explained a few days ago, interviewed by the New York Times. “Even the mildest forms of infection should leave at least short-term immunity against the virus in the recovering patient .
The growing concern about these possible cases of reinfection has nevertheless prompted the WHO to seriously address the issue. And the organization wants to be reassuring today.
“We are aware that some patients test positive after clinically recovering “, told AFP a spokesperson for the WHO. “But from what we currently know – and this is based on very recent data – it appears that these patients are actually expelling the remnants of material from their lungs , as part of the recovery phase .
In an interview with the BBC a few days ago, Maria Van Kerkhove, one of the people responsible for managing the pandemic at the WHO, had indeed assured that it was "dead cells" in the lungs that were coming back up and leading to the positive test. "It's not a contagious virus, it's not a reinfection, it's not a reactivation . This is part of the recovery process she insisted.
However, even though these results suggest thatinfected patients rapidly develop antibodies (within three weeks) and are therefore immune to Covid-19 at least in the short term, this does not answer crucial questions:are we completely immune after infection? And if so, to what degree and for how long? "We don't have an answer insisted Maria Van Kerkhove.
For some viruses, such as measles, those who contract it are immune for life. For others, such as SARS, immunity will last from months to years. Regarding SARS-CoV-2, we do not yet have enough perspective to draw this type of conclusion.
Source:AFP
