{"id":11858,"date":"2020-04-14T07:00:00","date_gmt":"2020-04-14T11:00:00","guid":{"rendered":"http:\/\/airpurifierspecialist.com\/store\/?p=11858"},"modified":"2020-05-25T11:25:35","modified_gmt":"2020-05-25T15:25:35","slug":"can-covid-19-infect-you-twice-mystery-cases-show-how-little-is-known-about-the-virus","status":"publish","type":"post","link":"https:\/\/airpurifierspecialist.com\/store\/can-covid-19-infect-you-twice-mystery-cases-show-how-little-is-known-about-the-virus\/","title":{"rendered":"Can COVID-19 infect you twice? Mystery cases show how little is known about the virus"},"content":{"rendered":"
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Everyone wants the virus that causes COVID-19 to be a one-and-done. But reports from South Korea are raising the possibility that infections can be \u201creactivated,\u201d or that the infected, once recovered, could be infected anew.<\/p>\n

At least 110 people in South Korea have tested positive for the pandemic virus after having been thought \u201ccured,\u201d according to reports. The World Health Organization told Reuters on Saturday the agency is \u201cworking hard to get information\u201d on the cases.<\/p>\n

It\u2019s believed the virus may have \u201creactivated\u201d in some people, as opposed to them being re-infected all over again, or that repeat testing may simply be picking up harmless fragments of virus genetic material that can linger for weeks or months after a person recovers.<\/p>\n

It could also come down to nothing more than faulty testing.<\/p>\n

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There are many different hypotheses<\/p>\n<\/blockquote>\n

Canadian health officials are trying to verify the information from South Korea. \u201cI think there are many different hypotheses,\u201d Dr. Theresa Tam, Canada\u2019s chief public health officer, said Monday. Tam said it\u2019s important to get \u201cour international partners to expand more on what is actually happening and maybe, yes, having an international collaboration in terms of looking at what happens to someone who has initially been infected.<\/p>\n

\u201cWe actually don\u2019t know if a test positive means that there is any viable virus in that particular person. That\u2019s one of the first questions to actually answer,\u201d Tam said.<\/p>\n

But the mystery cases illustrate just how little is known about the virus\u00a0 \u2014 \u201chow the human body actually mounts an immunity and what actually happens in the longer term,\u201d Tam said. That could hamper the herculean efforts being poured into developing vaccines and, in the absence of a vaccine, make natural herd immunity harder to achieve.<\/p>\n

Reports from Seoul<\/a> describe people who tested negative for COVID-19 using PCR (polymerase chain reaction) testing who, some days later, tested positive again.<\/p>\n

According to top U.S. infectious disease expert Dr. Anthony Fauci, advisor to the U.S. presidential COVID-19 task force, how long immunity lasts remains unknown. However, in an interview with the editor of the Journal of the American Medical Association,<\/a> Fauci said the virus isn\u2019t changing much, and that the working assumption, although there is not 100 per cent certainty, is that \u201cif we get infected in February or March and recover, that next September, October, the person who\u2019s infected, I believe, is going to be protected.\u201d<\/p>\n

While most people in the medical and scientific community share that thinking, \u201cwe\u2019d be foolish to think we know everything about this virus, given that we have only known about its existence for about four months,\u201d cautioned Dr. Isaac Bogoch, an infectious diseases physician and scientist with the Toronto General Hospital.<\/p>\n

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What proportion of people get immunity, to what extent do they have immunity, and how long immunity lasts are still unanswered questions, Bogoch said. \u201cWhen we hear about people being reinfected it obviously raises a few red flags.\u201d<\/p>\n

Bogoch believes that the most likely explanation is that the recovered patients tested positive using PCR (polymerase chain reaction) testing, which detects viral RNA, because they still carry some residual virus in the areas being swabbed, typically the back of the nose and throat. It doesn\u2019t mean they\u2019re contagious to others, or that the viral fragments are capable of causing disease. The test may be positive for days, even weeks after people have recovered from an infection.<\/p>\n

Another possibility is that some people who were initially told they were positive weren\u2019t positive, but then became positive. \u201cAnd of course, the third possibility that we really hope is unlikely is that there is either reinfection or reactivation of the virus,\u201d Bogoch said. \u201cObviously, we hope that\u2019s an unlikely scenario. But I think it still warrants exploration.\u201d<\/p>\n

With reactivation, the virus triggers another eruption, the way the virus that initially causes chicken pox, varicella zoster, can come back years later as shingles.<\/p>\n

\u201cI think these are remote, but not impossible scenarios,\u201d Bogoch said. Given that the virus is so new to humans, \u201cwe should at least be open-minded to other possibilities,\u201d he said.<\/p>\n