A man in Hong Kong has just been confirmed to have been re-infected by SARS-CoV-2. From STAT:
Researchers in Hong Kong on Monday reported what appears to be the first confirmed case of Covid-19 reinfection, a 33-year-old man who was first infected by SARS-CoV-2 in late March and then, four and a half months later, seemingly contracted the virus again while traveling in Europe.
The case raises questions about the durability of immune protection from the coronavirus. But it was also met with caution by other scientists, who questioned the extent to which the case pointed to broader concerns about reinfection.
There have been scattered reports of cases of Covid-19 reinfection. Those reports, though, have been based on anecdotal evidence and largely attributed to flaws in testing.
But in this case, researchers at the University of Hong Kong sequenced the virus from the patient’s two infections and found that they did not match, indicating the second infection was not tied to the first. There was a difference of 24 nucleotides — the “letters†that make up the virus’ RNA — between the two infections.
That’s not particularly good news. If recovery does not convey persistent immunity, it’s not particularly likely that a vaccine will, either. However, this is good news of a sort:
During his second infection, the man did not have any symptoms. Some patients go through their course of Covid-19 without showing symptoms, but researchers have also hypothesized that secondary cases of the coronavirus will generally be milder than the first. Even if immune systems can’t stop the virus from infecting cells, they might still rally some level of response that keeps us from getting sicker. During his first case, the patient had classic Covid-19 symptoms of cough, fever, sore throat, and headache.
We really need to know a lot more about asymptomatic COVID-19. Was this reinfection milder because it was the second time or was it milder because of the strain of the virus that was contracted or because of the way in which it was contracted? There’s an enormous amount that we just don’t know.
I think this interview of a Yale immunologist by another MD is enlightening on the risks of / from reinfection.
https://www.medscape.com/viewarticle/933621
This is the key quote.
“If you follow COVID-infected patients over time, their antibody levels do seem to wane to some degree within 2-3 months. But that is not a cause for alarm because that’s what happens when you get infected or when you become immunized for the first time. The antibody levels peak within the first couple of weeks and then eventually come down over a few months. That’s okay because you still have memory B cells specific to that antigen as well as a T-cell immune response to the viral antigen. So the second time you’re exposed to the same virus, you can mount a rapid, specific, and robust immune response. It’s likely that you won’t feel anything the second time you’re infected. It will be a pretty mild or asymptomatic infection.”
The article goes through other interesting topics.
Possible biological explanation for why it hits men worse then women.
Why some are sick months after “recovery”
The first generation of vaccines likely won’t prevent reinfection (but should prevent serious disease)
The importance of humidity in helping the body beat the virus
Previous infections with “cold” coronavirus creating cross-immunity to SARS-COV2.
Sort of makes you wonder if there’s more to the asymptomatic spread of SARS-CoV-2, doesn’t it?
Thank you for that, Curious.
Well, yeah, Dave. The data is a mess. We have no idea the extent of infection. Our entire policy response has been based upon false precision.
You wouldnt expect a 33 y/o to have a serious infection anyway. They do but it is uncommon. Not sure what to make of it. The doc CO cites is clearly pretty bright and well informed so I like her guesses better than mine, but this is the first time through this so they are guesses. I still think this fall will tell us a lot more about the disease. I hope she is correct that if people are re-infected that it will be mild. We are seeing a fair number of people with residual disease and worry about those if they have another symptomatic round.
Steve
OT (slightly) – I keep hearing that the lockdowns and social distancing have all been done solely to hurt Trump politically. Yet we have been doing what every other country in the world did, even Sweden which was just lockdown lite. So why did all of those other countries want to harm Trump? Having a hard time figuring this one out.
Steve
Not from me. As I have said repeatedly, I think that social distancing and facemasks are marginally effective.
I have acknowledged from the start that lockdowns could be effective but also pointed out that they can’t be sustained forever. They may have been necessary for a few weeks while other steps were taken but that time passed long ago. I read a piece yesterday making the case that lockdowns didn’t satisfy cost-benefit analysis. I decided not to post on it.
I’m not sure why lockdowns have been so prolonged. Because officials don’t know what else to do?
“Not from me. ”
No, just from every conservative on this blog and others. I dont really expect an answer. Their claim is so stupid I dont expect anyone to try to defend it.
“I read a piece yesterday making the case that lockdowns didn’t satisfy cost-benefit analysis.”
I have read a few claiming to make that analysis. The ones I have read all looked only at deaths. It is pretty clear now that we have a significant number of people unable to return to work or not at full capacity for weeks after the acute stage of the illness. Also, we dont really have a control. It would have been helpful if some country or state thought this was just the flu and everyone there agreed to not change their work and social habits. Then we would have a baseline. Alas, no one was willing to do that.
Steve
Lack of a baseline is a substantial reason that policy is an art rather than a science. That and that sometimes people don’t care what actually works so long as they get their way.
Wouldn’t Steve’s baseline country be Brazil?
No. Parts of Brazil did close. Also, given their young population not sure how it would correlate to first world countries.
https://www.businessinsider.com/brazil-eases-lockdown-coronavirus-deaths-peak-bolsonaro-ignores-2020-6
Steve
I’m skeptical that comparing the U. S. with Germany, Sweden, or Japan makes any sense. IMO the U. S. is best understood as two countries occupying the same physical boundaries: a first world country and a third world one. That’s actually quite a bit like Brazil.
France might be a good comparison except that France’s laws against keeping records based on race makes it less useful.