A 33- years of age male was found to have a second SARS-CoV-2 infection some four-and-a-half months after he was identified with his first, from which he recuperated. The guy, who revealed no signs, was detected when he went back to Hong Kong after a journey to Spain.
I am a virologist with expertise in coronaviruses and enteroviruses, and I’ve been curious about reinfections since the start of the pandemic. Since people contaminated with SARS-CoV-2 can often test favorable for the virus for weeks to months, likely due to the sensitivity of the test and leftover RNA pieces, the only method to actually respond to the question of reinfection is by sequencing the viral genome at the time of each infection and looking for differences in the hereditary code.
There is no released peer-review report on this guy– just a news release from the University of Hong Kong– although reports say the work will be published in the journal Medical Infectious Diseases Here I resolve some questions raised by the current report.
Why wasn’t the guy immune to reinfection?
Immunity to endemic coronaviruses– those that cause symptoms of the cold– is reasonably short-term, with reinfections occurring even within the exact same season. So it isn’t completely surprising that reinfection with SARS-CoV-2, the infection that causes COVID-19, might be possible.
Immunity is intricate and involves numerous systems in the body. That includes the generation of antibodies– through what’s known as the adaptive immune reaction– and through the actions of T-cells, which can assist to educate the body immune system and to specifically get rid of virus-infected cells. Scientists around the world are still discovering about resistance to this infection and so can’t state for sure, based on this one case, whether reinfection will be a cause for broad concern.
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How various is the 2nd pressure that infected the Hong Kong man?
” Stress” has a specific definition when referring to infections. Typically a various “pressure” is an infection that acts in a different way in some method. The coronavirus that infected this man in Europe is most likely not a brand-new stress.
A STAT News post reports that the hereditary make up of the sequenced virus from the patient’s 2nd infection had 24 nucleotides– foundation of the infection’s RNA genome– that varied from the SARS-CoV-2 isolate that contaminated him the first time.
SARS-CoV-2 has a genome that is comprised of about 30,000 nucleotides, so the infection from the guy’s second infection was roughly 0.08%different than the original in genome series. That reveals that the infection that triggered the 2nd infection was brand-new; not a recurrence of the very first virus.
The male was asymptomatic– what does that indicate?
The man wasn’t suffering any of the hallmark COVID-19 signs which might indicate he had some degree of protective immunity to the 2nd infection since he didn’t appear sick. But this is difficult to prove.
I see 3 possible explanations. The very first is that the immunity he gained from the first infection protected him and enabled a moderate second infection. Another possibility is that the infection was moderate due to the fact that he was presymptomatic, and went on to develop symptoms in the coming days. In some cases infections with SARS-CoV-2 are asymptomatic– at the moment it is difficult to determine whether this was due to the distinctions in the infection or in the host.
What can we state about reinfection based on this one case?
Only that it seems to be possible after enough time has expired. We do not understand how likely or typically it is to occur.
Should people who have recovered from COVID-19 still wear a mask?
As we are still learning more about how humans develop resistance to SARS-CoV-2 after infection, my recommendation is for continued masking, hand hygiene and distancing practices, even after recovery from COVID-19, to protect versus the capacity for reinfection.
Megan Culler Freeman is a Pediatric Infectious Illness Fellow at the University of Pittsburgh. This article originally appeared on The Conversation and is republished under an Imaginative Commons license. Check out the initial here
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