> This study provides evidence that re-infections with the same endemic coronavirus are not atypical in a time window shorter than 1 year and that the genetic basis of innate immune response maybe a greater determinant of infection severity than immune memory acquired after a previous infection.

http://www.columbia.edu/%7Ejls106/galanti_shaman_ms_supp.pdf

Even if you recover, there's not a lot of evidence now as to what the duration of immunity will be. With this spreading through the world at different paces, it means that, as commonly predicted, we will see continuous re-emergence as we do with other cold viruses and influenza.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/

This hypothesis ("SARS-Cov19 does not confer immunity") falls roughly under the same category as intelligent design: the claim is so exceptional that it's a priori unlikely to be found true, and laypeople are taking normal scientist hedge-speak and exaggerating the meaning in their heads (e.g. "evolution is just a theory").

There was never really any question to anyone with any serious scientific training that humans would develop some degree of immunity to this virus. That's why people were saying it was more likely to be assay error from the start. The only open question here is how long that immunity might last. Even then, it's fairly clear that short-term (~months to a year) immunity is highly likely.

(Note: I have a doctorate in biochemistry with a specialty in molecular biology, and I've studied virology and immunology. I'm not just tossing off uninformed opinions.)

No. As the person you're responding to pointed out: "The viruses that cause colds, many of which are also coronaviruses, are pretty adept at hitting people throughout their life."

You can get temporary immunity that lasts for a year or so and still be able to get reinfected multiple times in your life.

Yes. I'm talking about the question of immunity, not whether or not it's possible to get re-infected by new strains of the same virus, or whether or not immunity fades over time. It would be unlikely that this virus didn't confer at least short-term immunity to the host.

The viruses that cause colds primarily re-infect because they mutate at a very high rate. We aren't seeing that with this particular virus.

https://translational-medicine.biomedcentral.com/articles/10...

This is not claimed anywhere in the paper you linked to. They show a non-synonymous mutation in RNA-dependent RNA polymerase, and hypothesized that it could impact drug resistance.

> We found that viral strains with RdRp mutation have a median of 3 point mutations [range: 2–5], whereas viral strains with no RdRp mutation have a median of 1 mutation [range: 0–3] (p value < 0.001, Mann–Whitney test). The different distribution between the two groups relative to the number of mutations is statistically significant (Fig. 4).

So call the null hypothesis "there will be some level of immunity." But then you see some people testing positive again, and it's reasonable to want to know why. I didn't see people officials leaping to planning for zombie apocalypse "we're all gonna get it over and over forever" scenarios, I saw people saying we needed to dig deeper.

A lot of people in this discussion are refuting a straw man idea that everyone had decided "clearly you get no immunity at all".

I have been following the statements of experts ever since this myth made headlines.

And despite what the headlines said, the opinions of experts has always been clear. That being that these "reinfections" were the result of dead virus material being detected.

So, no it is not reasonable to have ever believed this, if you had listened to the experts.

Yes, but you're almost always immune for at least a year. By then, we should be getting close to a vaccine.

And when you do get one of those viruses again, it's significantly less severe the second time.