Reinfection risk - Printable Version

Reinfection risk - Printable Version

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Reinfection risk - JustAnotherFan - 06-23-2020

Someone in Austin, TX, just said they are now on their second round of Covid-19. Said they got it in late February (very early for Texas) and it was confirmed by testing. Now they are sick again. The claim is that her doctor said that several people have now tested positive for it twice in Austin.

Anecdotal, I can't verify it, but damn.

RE: Reinfection risk - akiddoc - 06-23-2020

Many people are excreting viral particles for a long period of time (weeks) after infection. Whether or not you can get it twice in quick succession is unclear.

RE: Reinfection risk - dabigv13 - 06-23-2020

I think it may be possible for some people to get infected again. It is likely dependent on an individual's immune system, which has immense variability in the human population. Single anecdotes should be interesting points worthy of follow up. But I don't think reinfection is likely to be a major driver of the pandemic. And most importantly, any second infection would almost certainly be less severe than the first one. If the immune system fought it off successfully once, memory cells will aid the response to a second infection. Perhaps someone who is very medically fragile, and in whom any viral URI could tip things over the edge, would still be at risk for a poor outcome. Hence nursing homes should be a key focus of high level PPE usage and testing of staff and residents. But I think reinfection in general should be a low level concern with the pandemic, and I have not seen any actual scientific literature showing it has actually ever occurred.

RE: Reinfection risk - Farm93 - 06-23-2020

(06-23-2020, 02:22 PM)akiddoc Wrote: Many people are excreting viral particles for a long period of time (weeks) after infection. Whether or not you can get it twice in quick succession is unclear.

Add to that the tests the USA has been using are not very reliable.

Lots of possible explanations. I would love to know if the strains are now different enough that it is possible to get sick twice in the same 6 month type window.

Having the virus in February and still having it in June feels a bit too long to me, but hard to know with limited anecdotal info.

RE: Reinfection risk - JustAnotherFan - 06-23-2020

(06-23-2020, 02:43 PM)Farm93 Wrote:
(06-23-2020, 02:22 PM)akiddoc Wrote: Many people are excreting viral particles for a long period of time (weeks) after infection. Whether or not you can get it twice in quick succession is unclear.
Add to that the tests the USA has been using are not very reliable.

Lots of possible explanations. I would love to know if the strains are now different enough that it is possible to get sick twice in the same 6 month type window.

Having the virus in February and still having it in June feels a bit too long to me, but hard to know with limited anecdotal info.

She tested negative in April so she and her doctor assumes it is a second infection.

And yes, she said this one is much less severe than the first one.

RE: Reinfection risk - fullmetal - 06-23-2020

What we haven't been able to determine is whether people are contagious during subsequent infections. If they are not, then that is excellent news. But if they are...herd immunity is no longer applicable.

RE: Reinfection risk - Goose - 08-24-2020

https://www.medpagetoday.com/infectiousdisease/covid19/88234?xid=NL_breakingnewsalert_2020-08-24&eun=g1475875d0r&utm_source=Sailthru&utm_medium=email&utm_campaign=CVreinfectAlert_082420&utm_term=NL_Daily_Breaking_News_Active

This is a single event, so it may not mean much. However, there is at least some evidence that it can happen.

RE: Reinfection risk - magnus - 08-24-2020

At least he was asymptomatic.

Any idea if he was contagious? They said that the viral load was high. Does that also mean he was shedding?

RE: Reinfection risk - M T - 08-24-2020

The two presumptive reinfections discussed in TWIV 638, July 12. (10:40 - 16:45)
   Dr. Daniel Griffin (speaker) patient:
      physician; at end of March whole family was PCR-positive, treated as outpatient;
      afterwards had high antibody levels; was a plasma donor in April;
      admitted to hospital 1st week of July (ie, sicker 2nd time around); PCR-positive; antibodies are barely detectable

   Washington, DC patient:
       was sick in April; PCR-positive; had a couple of negative tests before he went back to work;
     mid-June, son had COVID so he took care of him;
        week later, got sick; week further, went to ER & was PCR-positive;
        was sicker 2nd time around

He then mentions talking to a doctor that didn't test repeat patients because he thought they couldn't be getting COVID a second time.

NOTE: I have not been following TWIV since that broadcast. It is possible that there is further info on these cases. One could wonder whether these are repeat positives from the first infection.

The infection in the article of the first post of this thread reports that the genomes ARE different between the 1st & 2nd infection.

RE: Reinfection risk - dabigv13 - 08-24-2020

Was always likely it could happen. However from the recent genome typed case in the news, the second infection was asymptomatic and only caught on travel screening. Most second infections will likely be with mild or no symptoms. If they are symptomatic I would presume they could be infectious on a second go around, but asymptomatic probably not. And in any case important to remember the human immune system is widely variable, and these cases probably represent outliers, not the norm.

RE: Reinfection risk - M T - 08-24-2020

Damn, you mean we can't count on coronavirus cold reinfections to be asymptomatic all the time, just most of the time?

RE: Reinfection risk - OutsiderFan - 08-26-2020

[tweet]https://twitter.com/Laurie_Garrett/status/1298394053185343489[/tweet]

RE: Reinfection risk - DocSavage87 - 08-26-2020

(08-24-2020, 01:11 PM)M T Wrote: The two presumptive reinfections discussed in TWIV 638, July 12. (10:40 - 16:45)
   Dr. Daniel Griffin (speaker) patient:
      physician; at end of March whole family was PCR-positive, treated as outpatient;
      afterwards had high antibody levels; was a plasma donor in April;
      admitted to hospital 1st week of July (ie, sicker 2nd time around); PCR-positive; antibodies are barely detectable

   Washington, DC patient:
       was sick in April; PCR-positive; had a couple of negative tests before he went back to work;
     mid-June, son had COVID so he took care of him;
        week later, got sick; week further, went to ER & was PCR-positive;
        was sicker 2nd time around

He then mentions talking to a doctor that didn't test repeat patients because he thought they couldn't be getting COVID a second time.

There has been some thought that severity is tied to the size and location of the inocolum. If someone thinks they are immune and running around without a mask, or taking care of very sick people without one, then if their immunity isn't fully protective, it makes sense they could not only get it but have more severe symptoms because they were more cavalier about exposure?

RE: Reinfection risk - OutsiderFan - 08-27-2020

They totally buried the lede with that Brussels Times article.

Key takeaway: The virus that struck a previously infected person had 11 mutations from the initial one. This lowers the chances there can be a viable vaccine. Doesn't eliminate, but makes it less likely to be a silver bullet solution.

RE: Reinfection risk - dabigv13 - 08-27-2020

Not really. Consider the mRNA vaccines, which code only for the spike protein. Any genetic change in the rest of the genome will have no effect. Many genetic changes will not affect the protein structure anyway. And finally, the spike protein is likely to be very stable, since mutations which affect its protein structure would have a good chance of making the virus much less transmissible.

RE: Reinfection risk - BostonCard - 08-27-2020

11 mutations is nothing. SARS-CoV-2 is an RNA virus, and RNA viruses mutate, a lot. See this editorial:

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000003

(it's related to an article about the mutation rate of poliovirus, but nonetheless still relevant.

Quote:RNA viruses have high mutation rates, but they may tolerate them rather than revel in them. That they were optimized for genetic variation alone is a “just so story” that should be skeptically re-examined as the more complicated biological reality is revealed [26].

A vaccine is going to produce polyclonal antibodies, which aren't dependent on binding to one particular spot in the antigen. Thus, even when there are mutations to one part of the protein, other antibodies will still be able to protect against the virus. Where this could be a problem is with monoclonal antibodies, where the antibody is directed at a single part of the virus. That is why many companies use a "cocktail" of a couple different monoclonal antibodies.

BC

RE: Reinfection risk - magnus - 09-24-2020

BNO News is tracking worldwide reported reinfections here.

https://bnonews.com/index.php/2020/08/covid-19-reinfection-tracker/

Of note, several reinfections had more severe symptoms and one happened within 12 days of the first (theory is that the immune response had not fully developed)

RE: Reinfection risk - fullmetal - 09-24-2020

(08-27-2020, 12:30 PM)BostonCard Wrote: 11 mutations is nothing. SARS-CoV-2 is an RNA virus, and RNA viruses mutate, a lot. See this editorial:

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000003

(it's related to an article about the mutation rate of poliovirus, but nonetheless still relevant.

Side note: I believe the coronavirus genomes are unsegmented, which means their rate of mutations is lower (vs. segmented RNA genomes like the flu).

RE: Reinfection risk - akiddoc - 09-24-2020

Anecdotal cases of reinfection are really not of concern. Happens with every virus I can think of. Even varicella (chicken pox), which is genetically very stable and very immunogenic, had a reinfection rate of 1 or 2 percent before we had a vaccine. The vaccine has been extremely effective. I've only seen one case of wild chicken pox in the past 5 years. It was a 9 month old unimmunized kid visiting from another country who probably caught it on the 10 hour plane ride to the USA. IF we get a quality vaccine it will eventually shut this virus down to very low levels.

RE: Reinfection risk - JustAnotherFan - 10-12-2020

Okie dokie, here we go.

Scientists have confirmed the first case of coronavirus reinfection in the United States: a 25-year-old Nevada man whose second round of the virus was more severe than the first.

https://thehill.com/policy/healthcare/520702-scientists-confirm-nevada-25-year-old-got-coronavirus-twice-second-case-was