Reinfection

blindjustice wrote: »

https://news.rthk.hk/rthk/en/component/k2/1545589-20200824.htm?spTabChangeable=0

Researchers at the University of Hong Kong on Monday said they have proved that a Hong Kong man was infected with Covid-19 for a second time – the world’s first such documented case.

The 33-year-old IT worker was cleared of Covid-19 and discharged from a hospital in April. He tested positive for the virus again after returning from Spain earlier this month.

Health officials at first were unsure if the man was a "persistent carrier" of the virus from his previous infection.

But the HKU research team said genetic sequencing showed the virus strains contracted by him in April and August were “clearly different”. The study has been accepted by the Clinical Infectious Diseases journal, the researchers said.

“Many believe that recovered Covid-19 patients have immunity against re-infection because most developed a serum neutralising antibody response. However, there is evidence that some patients have waning antibody level after a few months," the researchers said.

“Our findings suggest that the SARS-CoV-2 may persist in the global human population as is the case for other common cold-associated human coronaviruses, even if patients have acquired immunity via natural infection,” they said.

Its not the first case, does anyone know if 2nd time infection was mild or severe?

Curious if he had some form of immunity after first strain dose (and only mild symptoms) or if effects are cumulative and more severe each strain.

Man found to be infected 4.5 months apart by different strains

https://www.bloomberg.com/news/articles/2020-08-24/hong-kong-reports-first-coronavirus-re-infection-in-it-worker

Can false positives on the original tests be ruled out?

Strange how the Hong Kong case tested positive but then negative for antibodies 10 days later, although possibly it was too soon for an antibody test.

I gather from French media (my French is poor so need help/confirmation) that the second infection is much lighter.
Anyone have anything on that yet?

Immunity is probably really nuanced, The case of the dutch woman re-infected with sars-cov-2 who died was 80 years old and undergoing cancer treatment (often this leads to lower immunity but I'm not sure on the details of this case)

We are used to thinking in binary terms, immune and not immune, and vaccination / infection leads to total immunity, but I have read that people get regularly re-infected with the same common cold coronaviruses all the time. Certain viruses seem to often confer sterilizing immunity (total immunity), but many seem to just prepare us better for future infections, meaning we have less severe disease or none at all but we still get infected and it still replicates in our system, and some seem to never bring about immunity at all.

Most of the other cases of re-infection I have heard the second case was less severe, but supposedly that was not the case with the second patient you mentioned, he apparently developed a more serious disease the second time around. Who knows why this is, there are some viruses that can actually cause more serious disease if you have some immune response from a previous infection/vaccination (antibody dependent enhancement), but I haven't heard any confirmation of that with this virus or this patient. Another speculation I heard on this case is that its possible this patient beat the infection with just his innate response or that it was confined to just his upper respiratory tract the first time, and the second time the viral infection reached his lower respiratory tract and/or achieved much higher infection and this lead to more severe disease as it was almost like it was the first infection for this guy.

From the very beginning one of the end-games I have heard proposed for this virus was that it would become endemic and due to our partial immunity, it would join the ranks with the other common coronaviruses in being another cold causing virus. Who knows if that will be the case but it sounds plausible. I wonder is re-infection much more common than we think but just much more likely to be very mild that we don't even detect them?

tobefrank321 wrote: »

Still less than 10 cases of reinfection out of almost 40 million confirmed cases. Not something to be overly concerned with.

Will be more. 30% of recovered patients do not produce antibodies for Corona at all. Virus mutating and these who got immune temporally are also in danger few months later. I'd guess low numbers are only because these who already had Covid just better protecting themselves than these who denies a danger because of their poor imagination.

SeaBreezes wrote: »

and each time more severe.

This is unlikely. Current death rate is much lower than we had in April. It can grow because IE run out of ICUs, but on present numbers it is MUCH lower than in April. Probably because most dangerous stains dying first, with their owners.

Why is the government not encouraging those recovered infected to be a seperate designation of person in our country, they are recovered and should be treated like people above those who have not been infected, gold for the economy where social distancing required.