Comment by pmoriarty | Hacker News Reader

Comment by pmoriarty | Hacker News Reader

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"Perhaps California could have attempted a middle ground strategy. Let the virus spread just a slight amount more than occurred during the initial lockdown in order to gradually spread immunity."

It's not even clear yet whether exposure to this virus confers immunity, nor how long such immunity would last if it does exist.

From the newest episode of This Week in Virology[1]:

Daniel Griffin: The tough thing, right, is that if you look at the "common" coronaviruses, they don't give us long-lasting immunity. Traditionally you could be reinfected multiple times in the same year. ... We've known this for the other coronaviruses, that if you get OC43 or 229e or any of the other, you don't get lifelong immunity, you can get sick again, and it's not clear that that second infection is milder than the first. My word of caution is to be careful about, you know, when we hear that 5 or 10 percent of the population is seropositive, I don't know what that means yet.

[1] - starting at about 14'34" in to episode 638: https://www.microbe.tv/twiv/twiv-638/

Though it has not been conclusively proven, literally all signs point to meanginful immunity and virtually no signs point to the opposite. Dozens of vaccines are being developed on this assumption, and there have been zero confirmed instances of reinfection of a fully recovered individual.

> all signs point to meanginful immunity and virtually no signs point to the opposite.

Here is a story from CNN via the Mercury News about 3 teachers sharing a classroom. Anecdotal, but makes me think these are signs of a lack of immunity. A positive, negative, positive test.

> A month after they caught the virus that killed their colleague, Martinez and Skillings are still struggling.

> Martinez says fatigue is lingering, she still has a cough, and she continues to take breathing treatments to relieve tightness in her chest. She recently tested negative and retested.

> Skillings says she thought she was getting better, but recently her cough returned full force. She tested a week ago and it came back positive again.

https://www.mercurynews.com/2020/07/12/three-arizona-teacher...

Right, when millions and millions of people become infected with an illness there will be a wide range of edge cases. But if reinfection within 6 months was anything other than exceptionally rare it would be obvious by now.

Now if you had a peer reviewed study to link instead of media reports, I would be very interested.

Not sure why you’re getting downvoted.

Seropositive tests have show the vast majority develop an immune response, how long that lasts we don’t know, but even if it’s only 6 months, that will reduce spread. You don’t create an epidemic plan based on edge cases.

And it’s important to note that the tests are looking for viral RNA. Viral RNA can be found even if virus are inactivated in the absence of an active infection or the shedding of active viruses.

No one yet knows whether the antibodies detected in seropositive tests actually confer protection against getting sick from this virus.

For some viruses, like, say, HIV, you can have lots of antibodies against it, but still be sick with HIV.

It is not yet clear whether SARS-CoV-2 is like HIV in this sense or if the antibodies produced by the body after infection with the virus actually confer protection against future infections.

That’s true, but what we know about the Coronavirus class suggests it’s not like HIV (where the immune response does little to control the infection). Again, there are a lot of unknowns, but focusing on edge scenarios or edge cases just leads down rabbit holes.

I work in the healthcare space, and a physician recommended this review recently published in JAMA.[1]. He felt it was probably the best summary of all the data that’s out there (>29,000 papers on Covid).

I found this particularly relevant - Although viral nucleic acid can be detectable in throat swabs for up to 6 weeks after the onset of illness, several studies suggest that viral cultures are generally negative for SARS-CoV-2 8 days after symptom onset.

[1] https://jamanetwork.com/journals/jama/fullarticle/2768391

There was a study where they tried to reinfect monkeys with the virus after they had developed a prior immune response. Even in laboratory setting, they could not reinfect the monkeys.

https://www.livescience.com/monkeys-cannot-get-reinfected-wi...

That, plus every case of supposed reinfection that has occurred so far is either inconclusive or proven to be a case of false positives. The big one was in South Korea, where the KCDC later determined that their test was picking up dead virus fragments.

It gets hard to keep pretending people can get COVID-19 over and over again. Maybe if had been documented 1000 times out of 13 million cases, but we haven't even seen anything close to that.

> No one yet knows whether the antibodies detected in seropositive tests actually confer protection against getting sick from this virus.

We do know when we do detailed antibody assays on people who are seropositive, that most have developed neutralizing antibodies

People like to act like this is the end of the world. It's easy to blame media here, as media is taking a handful of cases out of millions and making sweeping (end of the world) claims.

It seems you're moving the goalposts though. Your initial statement was that there were zero confirmed cases of reinfected individuals. The commentator gave you an example of such a case (and I can give you an another with the thoughts of a doctor [1]), then you moved back and said 'if it was anything more than exceptionally rare'.

At the very least can you maintain your argument? More dangerously could be the situation in which those that are asymptomatic initially end up with shorter duration immunity than those that have symptoms. Which would toss out a lot of our understanding of how severe the virus could end up being out the door.

[1] https://www.vox.com/2020/7/12/21321653/getting-covid-19-twic...

The positive, negative, positive cases are almost certainly testing artifacts rather than reinfections though - they all seem to involve someone who was infected testing positive after a relatively short time period, and researchers in countries like South Korea have found that the patients don't seem to have any viable virus or be able to infect others when they test positive for the second time: https://uk.reuters.com/article/us-health-coronavirus-southko...

As far as I know, their original claim is still true: there are zero confirmed reinfections with Covid-19.

I maintain that there is no peer-reviewed research proving that an individual can become infected after recovering from COVID-19. There are only scattered media reports.

However, I am not claiming it is strictly impossible. That has not been proven either. But at this point, we could only assume it is extremely rare, at least within a 5-6 month window.

I agree, I think there is likely meaningful immunity. But, it is very much up in the air on how long that immunity will last.

SARS immunity lasts a few years (1-3 years I believe). On the other hand, several extant coronaviruses contribute to the common cold, and my understanding is that immunity for these is only a few months or less. This is partly why one can catch a cold multiple times in a year.

It's also worth remembering that the common cold has many different sources, and only some of those are coronaviruses.

This comment has not aged well at all with several study preprints released in the last 12h indicating rapid loss of immunity and secondary infections

My comment has held true for 5 months and I have not seen or heard anything to convince me otherwise. Link? Or just more random media reports?

The immune system remembers. Some people's better than others. It'll all be OK.

Do you have a source?

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