5 ms·

“There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection”(see go.nature.com/3cutjq

“There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection”(see go.nature.com/3cutjqz). As of 3 days ago there is: https://science.sciencemag.org/content/early/2020/05/19/science.abc4776?fbclid=IwAR0crCPeMEZ1Zwzsq8BuONaajH_EOSG4hPNl5OHaMVJi8cqJVvhqR1rAB94 https://science.sciencemag.org/content/early/2020/05/19/scie...

jedberg 6y ago
In monkeys. That may or may not apply to humans. It certainly points to it working, but it's not conclusive. The only conclusive test will be a challenge test, where you purposely infect people, or waiting a year after a vaccine to check for reinfection rates.
- elbasti 6y ago
  Reminds me of the joke "if you're a mouse and you still have Alzheimer's, you need to get a new agent"
  - wolfhumble 6y ago
    The twitter account: https://twitter.com/justsaysinmice https://twitter.com/justsaysinmice might (?) agree with you! ;-)
StanislavPetrov 6y ago
Nor is there currently evidence that people who recovered from COVID-19 and have antibodies aren't immune.
- pbhjpbhj 6y ago
  I've read a few reports indicating reinfection, so I'm not sure that's true. There seems to be evidence, it needs collating, assessing, and interpreting by experts.
  - the8472 6y ago
    Those probably are false positives. http://www.koreaherald.com/view.php?ud=20200429000724 http://www.koreaherald.com/view.php?ud=20200429000724
SiempreViernes 6y ago
Citing your paper: "However, there is currently no data whether humans who have recovered from SARS-CoV-2 infection are protected from re-exposure" (Under discussion, first paragraph) A more fair summary is that they tested on monkeys and the results looks good, in their words: """ We developed a rhesus macaque model of SARS-CoV-2 infection that recapitulates many aspects of human SARS-CoV-2 infection, including high levels of viral replication in the upper and lower respiratory tract (Fig. 1) and clear pathologic evidence of viral pneumonia [...] data suggest the utility of rhesus macaques as a model for SARS-CoV-2 infection for testing vaccines and therapeutics and for studying immunopathogenesis [...] However, neither nonhuman primate model led to respiratory failure or mortality, and thus further research will be required to develop a nonhuman primate model of severe COVID-19 disease. Given the near-complete protection in all animals following SARS-CoV-2 rechallenge, we were unable to determine immune correlates of protection in this study. [...] Moreover, additional research will be required to define the durability of natural immunity. """
goalieca 6y ago
There's also this review which shows "limited evidence". https://jamanetwork.com/journals/jama/fullarticle/2766097 https://jamanetwork.com/journals/jama/fullarticle/2766097 I think this is scientist talk for meaning "likely" but "not exhaustively proven" yet. The article explains the situation very well and I suggest a thorough read. It would be very upending if a virus such as this one did not confer immunity. edit: from the referenced article: > To date, no human reinfections with SARS-CoV-2 have been confirmed.
- joe_the_user 6y ago
  I suspect viral load is involved. If someone is exposed to enough virus, or often enough, the default antibody response may not be enough. That's the thing about "immunity passport", it implies here you have someone you can expose to the virus all day long. I suspect no one can survive unlimited expose to whatever deadly disease without getting sick. I mean, as I understand it, for most diseases, the purpose of vaccines is to get the (over-used) "herd immunity", meaning people are immune enough on average to stop the spread of the disease. Situation were a substantial portion of people refuse vaccines (thanx, antivaxer) can result in outbreaks where vaccinated people also get sick.
  - amluto 6y ago
    Exposure cuts both ways. In some cases, constant reexposure increases immunity. For example, shingles is believed to be less likely if you are regularly re-exposed to chicken pox.
    - joe_the_user 6y ago
      But that doesn't seem like a direct counter-example, since it doesn't involve not getting sick from a high viral load.
  - goalieca 6y ago
    > I suspect viral load is involved. You mean dose? The current vaccine research is measuring antibody titres (how much) is being generated by an inoculated individual in reference to a recovered patient. The next step is to determine if those antibodies are actually sufficient as they are different.
godelski 6y ago
From my understanding, it should be the other way around that's proved. Because that's kinda how the immunity system works. AFAIK the viruses that you don't get immunity from (assuming you get it and recover) are the odd ones. Like HIV, and from what I know there can be hundreds or thousands of variations of the virus inside a single person.
- jniedrauer 6y ago
  There are viruses where immunity to one strain makes subsequent infections with other strains much worse[0]. So far there only seems to be one strain of SARS-CoV-2, but it's definitely a risk worth considering. [0]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333201/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333201/
- jpollock 6y ago
  Chickenpox is another one, it can re-erupt as shingles when older. My googling also turns up herpes, Epstein-Barr, measles(!), HPV, Hep-B [1]... It looks like there are many diseases which can find a host reservoir in our body to hide out for a while. [1] https://www.ncbi.nlm.nih.gov/books/NBK8538/ https://www.ncbi.nlm.nih.gov/books/NBK8538/
  - mc32 6y ago
    Ebola too, i think would hide in peoples’s eyes and come back in some cases, if I recall correctly.
  - godelski 6y ago
    So there's nuance to this that's important. Let's look at measles[0] because we get vaccinated for it (which shows that we can get immunity) but the report says that 9% of cases were people who had been vaccinated. The crux of this is that immunity doesn't last forever but does last for awhile. In measles it looks like 15 years after your two standard MMR vaccines you get from a kid. We have to recognize too that vaccines aren't perfect. Your immune system might not make as strong of an antibody response as another person. You may lose immunity sooner than others. Etc. But the whole premise of the vaccine is that you can get immunity. And if we look at this study, this worked out for most people. Not many people got measles, and of those that did only 9% were vaccinated, which shows that there is a substantial bias for those that weren't vaccinated. So when I'm saying that people get get immunity I don't mean forever and to every strain, but that they generally get some protection. In fact, this is an essential component to vaccine theory. If you gain __NO__ immunity (for any period of time) from covid, then a vaccine isn't going to do anything because you can't build an immunity. If you get immunity for a year (like with the flu), I think that's a pretty acceptable risk for many and shows that we could build substantial herd immunity just with the younger populations (like with the flu, which the vaccine there isn't even that great, but better than nothing). And as another note on Shingles, I don't know about you, but chickenpox parties (because it is A LOT worse when you're older) were a thing when I was a kid (I'm not even 30!) and less than 1% of people get shingles. The main factors are being old, immunocompromised, and getting chickenpox before you're 18 months old. Saying you can get reinfected and will get reinfected are different statements with different risk values. [0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4979181/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4979181/

jedberg 6y ago

In monkeys. That may or may not apply to humans. It certainly points to it working, but it's not conclusive. The only conclusive test will be a challenge test, where you purposely infect people, or waiting a year after a vaccine to check for reinfection rates.

elbasti 6y ago
Reminds me of the joke "if you're a mouse and you still have Alzheimer's, you need to get a new agent"
- wolfhumble 6y ago
  The twitter account: https://twitter.com/justsaysinmice https://twitter.com/justsaysinmice might (?) agree with you! ;-)

StanislavPetrov 6y ago

Nor is there currently evidence that people who recovered from COVID-19 and have antibodies aren't immune.

pbhjpbhj 6y ago
I've read a few reports indicating reinfection, so I'm not sure that's true. There seems to be evidence, it needs collating, assessing, and interpreting by experts.
- the8472 6y ago
  Those probably are false positives. http://www.koreaherald.com/view.php?ud=20200429000724 http://www.koreaherald.com/view.php?ud=20200429000724

SiempreViernes 6y ago

Citing your paper: "However, there is currently no data whether humans who have recovered from SARS-CoV-2 infection are protected from re-exposure" (Under discussion, first paragraph) A more fair summary is that they tested on monkeys and the results looks good, in their words: """ We developed a rhesus macaque model of SARS-CoV-2 infection that recapitulates many aspects of human SARS-CoV-2 infection, including high levels of viral replication in the upper and lower respiratory tract (Fig. 1) and clear pathologic evidence of viral pneumonia [...] data suggest the utility of rhesus macaques as a model for SARS-CoV-2 infection for testing vaccines and therapeutics and for studying immunopathogenesis [...] However, neither nonhuman primate model led to respiratory failure or mortality, and thus further research will be required to develop a nonhuman primate model of severe COVID-19 disease. Given the near-complete protection in all animals following SARS-CoV-2 rechallenge, we were unable to determine immune correlates of protection in this study. [...] Moreover, additional research will be required to define the durability of natural immunity. """

goalieca 6y ago

There's also this review which shows "limited evidence". https://jamanetwork.com/journals/jama/fullarticle/2766097 https://jamanetwork.com/journals/jama/fullarticle/2766097 I think this is scientist talk for meaning "likely" but "not exhaustively proven" yet. The article explains the situation very well and I suggest a thorough read. It would be very upending if a virus such as this one did not confer immunity. edit: from the referenced article: > To date, no human reinfections with SARS-CoV-2 have been confirmed.

joe_the_user 6y ago
I suspect viral load is involved. If someone is exposed to enough virus, or often enough, the default antibody response may not be enough. That's the thing about "immunity passport", it implies here you have someone you can expose to the virus all day long. I suspect no one can survive unlimited expose to whatever deadly disease without getting sick. I mean, as I understand it, for most diseases, the purpose of vaccines is to get the (over-used) "herd immunity", meaning people are immune enough on average to stop the spread of the disease. Situation were a substantial portion of people refuse vaccines (thanx, antivaxer) can result in outbreaks where vaccinated people also get sick.
- amluto 6y ago
  Exposure cuts both ways. In some cases, constant reexposure increases immunity. For example, shingles is believed to be less likely if you are regularly re-exposed to chicken pox.
  - joe_the_user 6y ago
    But that doesn't seem like a direct counter-example, since it doesn't involve not getting sick from a high viral load.
- goalieca 6y ago
  > I suspect viral load is involved. You mean dose? The current vaccine research is measuring antibody titres (how much) is being generated by an inoculated individual in reference to a recovered patient. The next step is to determine if those antibodies are actually sufficient as they are different.

godelski 6y ago

From my understanding, it should be the other way around that's proved. Because that's kinda how the immunity system works. AFAIK the viruses that you don't get immunity from (assuming you get it and recover) are the odd ones. Like HIV, and from what I know there can be hundreds or thousands of variations of the virus inside a single person.

jniedrauer 6y ago
There are viruses where immunity to one strain makes subsequent infections with other strains much worse[0]. So far there only seems to be one strain of SARS-CoV-2, but it's definitely a risk worth considering. [0]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333201/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333201/
jpollock 6y ago
Chickenpox is another one, it can re-erupt as shingles when older. My googling also turns up herpes, Epstein-Barr, measles(!), HPV, Hep-B [1]... It looks like there are many diseases which can find a host reservoir in our body to hide out for a while. [1] https://www.ncbi.nlm.nih.gov/books/NBK8538/ https://www.ncbi.nlm.nih.gov/books/NBK8538/
- mc32 6y ago
  Ebola too, i think would hide in peoples’s eyes and come back in some cases, if I recall correctly.
- godelski 6y ago
  So there's nuance to this that's important. Let's look at measles[0] because we get vaccinated for it (which shows that we can get immunity) but the report says that 9% of cases were people who had been vaccinated. The crux of this is that immunity doesn't last forever but does last for awhile. In measles it looks like 15 years after your two standard MMR vaccines you get from a kid. We have to recognize too that vaccines aren't perfect. Your immune system might not make as strong of an antibody response as another person. You may lose immunity sooner than others. Etc. But the whole premise of the vaccine is that you can get immunity. And if we look at this study, this worked out for most people. Not many people got measles, and of those that did only 9% were vaccinated, which shows that there is a substantial bias for those that weren't vaccinated. So when I'm saying that people get get immunity I don't mean forever and to every strain, but that they generally get some protection. In fact, this is an essential component to vaccine theory. If you gain __NO__ immunity (for any period of time) from covid, then a vaccine isn't going to do anything because you can't build an immunity. If you get immunity for a year (like with the flu), I think that's a pretty acceptable risk for many and shows that we could build substantial herd immunity just with the younger populations (like with the flu, which the vaccine there isn't even that great, but better than nothing). And as another note on Shingles, I don't know about you, but chickenpox parties (because it is A LOT worse when you're older) were a thing when I was a kid (I'm not even 30!) and less than 1% of people get shingles. The main factors are being old, immunocompromised, and getting chickenpox before you're 18 months old. Saying you can get reinfected and will get reinfected are different statements with different risk values. [0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4979181/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4979181/