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As other commenters have noted, this case study further supports the widespread observations that COVID-19 vaccines reduce the chance of severe (symptomatic) il

As other commenters have noted, this case study further supports the widespread observations that COVID-19 vaccines reduce the chance of severe (symptomatic) illness but do not necessarily prevent infection and transmission. The authors of this study conjecture that the unvaccinated asymptomatic “patient 40” may have been the source of the infections seen in the other fully vaccinated patients - however this was a minor point as limited rational and evidence was provided. That being said, IMO there seems to be a growing public opinion that unvaccinated individuals are to blame for the increasing dominance of variants of concern (delta, gamma, etc). One counterpoint that I’ve come across during my own review of the literature, is the idea that imperfect vaccines can cause selective pressure which enhances the fitness of highly virulent pathogens. For example see this peer reviewed publication from 2015: “Imperfect Vaccination Can Enhance the Transmission of Highly Virulent Pathogens” (https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002198 https://journals.plos.org/plosbiology/article?id=10.1371/jou...). My understanding is that this is a relatively new and perhaps highly understudied phenomenon. I wanted to share the idea here because it seems conspicuously missing from many of these discussions. Furthermore, I’d love to hear feedback from someone with more expertise - or just trade relevant links with others who are diving into primary sources as a way to form an educated and well rounded opinion.

Izkata 5y ago
> One counterpoint that I’ve come across during my own review of the literature, is the idea that imperfect vaccines can cause selective pressure which enhances the fitness of highly virulent pathogens. This is what happened with "Marek's disease", a virus-caused disease in chickens. The vaccine was "leaky" and ended up selecting for a more deadly form, such that now all chickens worldwide have to be vaccinated for it or they'll die if they get infected - which didn't used to be the case. https://en.wikipedia.org/wiki/Marek%27s_disease https://en.wikipedia.org/wiki/Marek%27s_disease
- sschueller 5y ago
  So does this mean we made this pandemic worse than the one from 1918 when we didn't have a vaccine?
  - mlang23 5y ago
    This is very likely. And has already been said by various critics already months ago. But these people were silenced or ridiculed, because it apparently was already decided the vaccines need to be sold.
    - evgen 5y ago
      Completely untrue. The reservoir of selfish unvaccinated individuals is what is providing a place for Covid to hide and mutate. Vax critics were silenced and ridiculed because they are dangerous deceivers who need to be called out and held to account for the consequences of their lies.
      - native_samples 5y ago
        That's not something that's ever been a problem with vaccines before. Even if you have unshakeable faith in this evidence-free perversion of biological theory, nobody was claiming the vaccines will fail without 100% adoption last year when they launched. Their reception would have been rather different if that had been claimed, wouldn't it? So you can either believe this is true, in which case governments and pharma firms deceived people about the nature of the 'vaccine', or you can believe it's false and they didn't. But you can't believe it's true and it's the other people who are deceivers. That makes no logical sense.
        samus 5y ago
        It's a general issue with every vaccine against an illness that has a reservoir. The reservoir can be other species (birds and various other animals in case of influenza) or it can be human populations that for various reasons have not eliminated the spread of the illness yet (measles in countries that refuse or make it difficult to vaccinate, polio if not completely eradicated yet). In this reservoir the agent has opportunity to mutate, and it can never be excluded that at some point it makes inroads into populations again where it was eradicated before. Global eradication of diseases has been achieved with smallpox and bovine rinderpest precisely because they had no natural reservoir and all vulnerable populations could be vaccinated. With Coronaviruses the situation is not so simple, but it should at least be possible to eradicate the currently relevant variant.
- the_mitsuhiko 5y ago
  Not all chicken get vaccinated.
- yyyk 5y ago
  1) All current variations of concern come from mostly unvaccinated countries. Apparently there's a serious issue with immunocompromised individuals and the vaccines may help prevent that: https://www.scientificamerican.com/article/covid-variants-may-arise-in-people-with-compromised-immune-systems/ https://www.scientificamerican.com/article/covid-variants-ma... 2) We can see with SARS and MERS that a more deadly form may actually reduce overall mortality, since the virus can't spread as effectively. However, we haven't had this effect so far.
  - erdewit 5y ago
    From the article: > Analysis of samples from the patient showed that the virus evolved rapidly after the plasma therapy, developing mutations that changed how it could infect cells and resist antibodies. Seems to be that the plasma therapy (injecting antibodies) is responsible here.
    - yyyk 5y ago
      There are cases of mutation in immunocompromised preceding plasma therapy, e.g.: https://www.npr.org/sections/goatsandsoda/2021/02/05/964447070/where-did-the-coronavirus-variants-come-from https://www.npr.org/sections/goatsandsoda/2021/02/05/9644470...
  - jstanley 5y ago
    > All current variations of concern come from mostly unvaccinated countries. Isn't it more significant not where they emerge (which is by random mutation) but where they do well? And don't they seem to do well in countries that have vaccinated more people? Is it even particularly easy to say where a variant originated? Could the mutations happen multiple times independently?
    - yyyk 5y ago
      >Isn't it more significant not where they emerge (which is by random mutation) but where they do well? Random mutation happens more when we give it more chances, by letting it infect more unprotected people. We'd rather avoid that, so it's also important. >Is it even particularly easy to say where a variant originated? No, but we have gene sampling to help. >Could the mutations happen multiple times independently? They can and sometimes do happen independently.
- sampo 5y ago
  > This is what happened with "Marek's disease" Marek's disease in chicken is what the PLOS article is about: MDV = Marek's disease virus. > The vaccine was "leaky" and ended up selecting for a more deadly form The researchers of the PLOS article do not claim to know that for certain: "Our data do not demonstrate that vaccination was responsible for the evolution of hyperpathogenic strains of MDV, and we may never know for sure why they evolved in the first place." But this they claim: "But whatever was responsible for the evolution of more virulent strains in the first place (and there may be many causes), our data show that vaccination is sufficient to maintain hyperpathogenic strains in poultry flocks today." https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002198 https://journals.plos.org/plosbiology/article?id=10.1371/jou...
murphyslab 5y ago
> imperfect vaccines can cause selective pressure which enhances the fitness of highly virulent pathogens The number of ways in which we undertaking a natural experiment in viral evolution has been top-of-mind for me as well. But the greater issue in my view is not that the vaccines are imperfect. All vaccines are somewhat imperfect. On its own, I the mRNA vaccines were probably entirely adequate. The problem is that the human population, as a result of policy decisions, will continue to have an immediately-adjacent reservoir of infection [0] with whom we are constantly in contact. I speak, of course, of the large numbers of unvaccinated among us. With vaccinated-to-vaccinated chains of transmission, there's a greater chance that a chain of vaccine-resistant variant will die out because the vaccine both reduces the risk of becoming infected [1] and the risk of transmitting infection [2]. But in a heterogeneous population, with large numbers of unvaccinated individuals, those chains of transmission can go on indefinitely, hopping back-and-forth between the two populations. That's a far greater risk here than the issue of a "leaky" vaccine. A vaccine might "leak" a little bit, yet the probabilities of infection and subsequent infection remain so low that all chains of transmission quickly terminate. Instead, we have a situation where the virus can slip into a separate (reservoir) population where it continues unchecked. That, in my view, is the real risk to furthering infection. [0] https://en.wikipedia.org/wiki/Natural_reservoir https://en.wikipedia.org/wiki/Natural_reservoir [1] https://www.cdc.gov/media/releases/2021/p0607-mrna-reduce-risks.html https://www.cdc.gov/media/releases/2021/p0607-mrna-reduce-ri... [2] https://sporevidencealliance.ca/wp-content/uploads/2021/06/Transmissibility-of-COVID-19-Among-Vaccinated-Individuals_Plain-Language-Summary.pdf https://sporevidencealliance.ca/wp-content/uploads/2021/06/T...
- marton78 5y ago
  In addition, the vaccines currently in use -- at least in the West -- are either mRNA or vector vaccines containing only parts of the virus (as far as I know only the spike protein from the virus's surface). I would expect them to result in a more specific immunity which is easier for the virus to circumvent, my mutating only its spike protein. Conventional vaccines however, which are more prevalent in the developing world, as well as having gone through COVID, should provide a broader immunity - at least in my half-educated view.
becuzThrowaway 5y ago
My understanding is that there is very little evidence of vaccinated individuals actually transmitting the original ("wild-type") virus, or even the Alpha variant (obviously, Delta/Gamma are potentially different beasts). This was why we in the United States dropped mask mandates for vaccinated individuals. I don't know why the narrative always reverts to "oh, the vaccines just decrease symptoms", a statement unsupported by evidence. EDIT: Before I get downvoted completely into oblivion, take a look at the 90% reduction in infections, both symptomatic and asymptomatic, seen in vaccinated individuals in Israel. https://pubmed.ncbi.nlm.nih.gov/33964222/ https://pubmed.ncbi.nlm.nih.gov/33964222/ I think we can all agree that you can't transmit the virus if you yourself don't get infected.
- standapart 5y ago
  The amount of abstract certainty present in this comment is truly astonishing. Please just cite the RCT on this.
  - becuzThrowaway 5y ago
    https://pubmed.ncbi.nlm.nih.gov/33964222/ https://pubmed.ncbi.nlm.nih.gov/33964222/
    - standapart 5y ago
      This is not an RCT. The work itself makes this very clear, it's observational, based on what we'll call "pseudo-voluntary" testing. Just provide the RCT for your claims-- this is necessary since the vaccine is known to be effective on a symptomatic level.
      - becuzThrowaway 5y ago
        Please provide the RCT that shows that vaccinated individuals have similar levels of infection to unvaccinated individuals. What the RCTs for Pfizer and Moderna showed was that the vaccines reduced the symptomatic infection rate by 95%. But you are misconstruing the language being used if you extend that to say "the vaccine is known to be effective on a symptomatic level". The statement about symptomatic infection just means that it was impractical to have 42,000 people take a COVID nasal swab every day, and therefore they can make no professional scientific statements about the actual rate of infection. But if you are aware of an RCT that actually established the vaccine as being ineffective at preventing infection, I would love to see it. EDIT: And yes, I linked to observational data from Israel (TWICE) that showed real-world effectiveness in preventing both symptomatic and asymptomatic infections.
aranw 5y ago
> imperfect vaccines can cause selective pressure which enhances the fitness of highly virulent pathogens I've wondered this ever since the UK changed it's approach and now that we've got to a state where there is pretty much no restrictions. I think scientists around the world also have this concern with the UK's approach
- jsbdk 5y ago
  Why would I want to vaccinate if I'm still going to get restricted? I mean the whole deal here was that if we got vaccinated we'd be back to normal life. If that wasn't the case they should've been sincere up front and most of us wouldn't have gotten vaccinated.
  - ben_w 5y ago
    Same reason I want to wear a seatbelt even though I’m still restricted by the speed limit: demonstrably lower chances of not merely death but also sub-fatal harm.
    - thirsty-dove 5y ago
      Doesn't seem like a good comparison, because seat belts have been tested for decades and don't seem to be insidiously harmful, whereas VAERS already has an off-the-charts number of reports of deaths and harm. Not a day goes by where I don't hear about somebody dying shortly after getting the vaccine, often in novel ways like described here: https://freewestmedia.com/2021/06/27/surgeon-who-operated-on-young-italian-vaccine-victim-you-have-never-seen-anything-like-this/ https://freewestmedia.com/2021/06/27/surgeon-who-operated-on...
      - ben_w 5y ago
        Even if all of the VAERS reports were both causal (they’re not) and fatal (not even remotely) the vaccine would still be seven times better than the illness. As the reports are overwhelming not about surprise deaths and not causal, the vaccines are somewhere between 170 times better and infinitely better than the disease. > Not a day goes by where I don't hear about somebody dying shortly after getting the vaccine, often in novel ways like described here And how many do you expect by coincidence in an ideal case where there are exactly zero side effects? Because it isn’t going to be zero coincidental deaths when there are 3.79 billion vaccination events. Not even zero per day.
Pyramus 5y ago
A couple of comments: > [...] vaccines reduce the chance of severe (symptomatic) illness but do not necessarily prevent infection and transmission. My understanding is that at least the RNA vaccines are sterilizing when titers peak, i.e. in the first weeks (months?) after full vaccination. This is due to the presence of a certain type of antibody in the mucosa of the respiratory tract. We also know that levels decrease over 6-12 months, at which point you can get infected, but illness will be mild due to T cell activity. (assuming the immune system of a young, healthy person). > My understanding is that this is a relatively new and perhaps highly understudied phenomenon. I don't have the impression it's understudied. With the widespread prevalence of genetic sequencing we have a pretty good understanding of the mutation activity. Once a variant has an evolutional advantage it is studied quite closely whether it is a fitness escape, an immune escape or both. E.g. Delta is mostly a fitness escape but fortunately only a slight immune escape. > or just trade relevant links with others who are diving into primary sources as a way to form an educated and well rounded opinion. The best resource I can give you is a German podcast with two of Germany's leading virologists [1]. Personally listening to experts in their field in a long form interview has been orders of magnitude more insightful. It's one thing to read an article in Vanity Fair whether the virus has escaped from a lab, it's a totally different thing to listen to an expert that actually knows how to do gain of function research. Maybe it's worth translating the transcriptions? [1] https://www.ndr.de/nachrichten/info/podcast4684.html https://www.ndr.de/nachrichten/info/podcast4684.html
trhway 5y ago
>the widespread observations that COVID-19 vaccines reduce the chance of severe (symptomatic) illness but do not necessarily prevent infection and transmission. that puts worksplace/etc. mandates into spotlight as their main rationale is to prevent the spread, ie. supposedly "it is not for you, it is for the others". So, it sounds like as a result of such mandates we may end up in a situation where the only people spreading virus at work/hospitals/government offices/etc. would be the ones with a highly virulent variety less susceptible to vaccines.
dot1x 5y ago
> That being said, IMO there seems to be a growing public opinion that unvaccinated individuals are to blame for the increasing dominance of variants of concern (delta, gamma, etc). This is no coincidence. The media has been directed to _not_ blame vaccines for ANYTHING, as doing so would negatively impact their narrative. It's well known that people vaccinated with leaky vaccines are the breeding ground for super-bugs, especially between they get their 1st and 2nd dose. The problem? Since their immune system has been trained for only the spike protein, they will be at an immune disadvantage once the variant learns how to completely circumvent the vaccine-induced immune response (and trust me, that's where we're going with all these variants, it's no coincidence Pfizer is prepping the 3rd shot). Once SARS-COV-2 has mutated enough to evade the current vaccine, we're going to have a resurgence of hospitalization and severe covid cases all around the world, but this time in VACCINATED people. Since their immune system has been primed by an incomplete vaccine, it will not generate multi-epitope antibodies any longer as it'll think "it got this handled" due to previous (incomplete) antibodies. Of course, the media will blame the "unvaxxed", just as they started doing right now. More lockdowns will commence, more vaccines every few months (with compounding risks). Oh, did I mention that subsequent vaccines will be less effective the more you get vaccinated, because your body is already primed and it'll produce the antibodies from the 1st vaccines? Look into "Original Antigenic Sin" or OAS.
- dot1x 5y ago
  Downvote as much as you want, the truth ain't changing :)
  - drdeca 5y ago
    I didn’t downvote the original comment, but my understanding of the social conventions here is that complaining about downvotes is frowned upon.
- yyyk 5y ago
  'It's well known that people vaccinated with leaky vaccines are the breeding ground for super-bugs, especially between they get their 1st and 2nd dose.' It's well known immunocompromised people are breeding grounds. One way to avoid that is vaccinating them early. 'it will not generate multi-epitope antibodies any longer as it'll think "it got this handled" due to previous (incomplete) antibodies.' The immune system knows to benchmark existing antidotes. If the spike antibody isn't enough it will stop producing it.
lmilcin 5y ago
> As other commenters have noted, this case study further supports the widespread observations that COVID-19 vaccines reduce the chance of severe (symptomatic) illness but do not necessarily prevent infection and transmission. Your argument that the vaccine stops only symptoms and not the infection is false. If that was true, we would not see countries that practically eradicated the virus instantly after vaccination (like Israel). The virus would still be spreading and infecting people, and those unvaccinated would still be getting seriously ill. > That being said, IMO there seems to be a growing public opinion that unvaccinated individuals are to blame for the increasing dominance of variants of concern (delta, gamma, etc). The vaccines have proved to be effective preventing infection from the original strains. If people have vaccinated then, it is likely we would have been done with the virus. Now, there were not enough vaccine doses to vaccinate everybody in the world in time, so a strain developing in a poor country could still reach western world. So it may not have been possible to prevent delta completely.
- pigeonhole123 5y ago
  Coparing Jordan and Israel, their new cases and death graphs look very similar. Israel has a 60% vaccination rate and Jordan has 20%. Where did you get this "instantly eradicated" idea from?
- effie 5y ago
  > countries that practically eradicated the virus instantly after vaccination (like Israel) Source for this absurd claim?
  - lmilcin 5y ago
    It is not an absurd claim. The statistics are available to everybody. Israel implemented vaccinations efficiently and very quickly their infection rates dropped close to zero. I live in Poland and same thing happened here. Now the infection rates grow again because the current vaccination rate and vaccine themselves are not enough to protect.
    - glandium 5y ago
nikolay 5y ago
Many young people have still a low chance of severe course of the disease but they are pushed to get vaccinated. My issue with the disease is not the severe course, which some people are pretty well protected from, but the lasting tissue and organ damage going thru the infection with or without a vaccine. I yet have to see a study showing that vaccines prevent such damage. We will have huge epidemics of CVDs after this is over as nobody really pays now close attention to people who pass thru the disease with or without symptoms.
- scotty79 5y ago
  It is possible that covid gives you brain damage even if you have mild symptoms https://www.businessinsider.com/covid-19-survivors-gray-matter-brain-tissue-long-term-study-2021-6?IR=T https://www.businessinsider.com/covid-19-survivors-gray-matt... Not sure if vaccines prevent any of this. They surely prevent damage by reducing infection rates in fully vaccinated, but not sure if they can save you from damage, same way they are saving you from death if you contract the virus anyways. https://www.medrxiv.org/content/10.1101/2021.07.13.21260393v1 https://www.medrxiv.org/content/10.1101/2021.07.13.21260393v...
  - nikolay 5y ago
    My point is that many restrictions are removed for fully-vaccinated people, i.e. the exposure of these people will increase, i.e. the chance of getting the infection, even if it doesn't take you to the hospital, greatly increases. Even if it's a small percentage, this means many people will get lasting damage. To me, vaccination status should not mean you can take your face mask off - first, you can still get stick, and, second, you can still bridge two sick people even better as you're less likely to show symptoms when you still carry the virus and exhale it without the mask.
    - samus 5y ago
      It's of course not ideal that restrictions are unduly waived. But it is also recognized that many won't consider taking the vaccine because they don't see how doing so contributes to end the pandemy. Luring them with incentives like entry to bars without testing, or positive monetary rewards, changes the decision making process though. But many places maintain restrictions like mask wearing or mandatory testing for a reason.
maxerickson 5y ago
All vaccines are imperfect. The mRNA vaccines are relatively effective. The strains that are spreading were first detected well before widespread vaccination. Widespread vaccination can increase the relative fitness of an existing strain of course, if it more or less eradicates less infectious strains.
Gravityloss 5y ago
The MRNA vaccine was developed fast, it's the testing that took a long time. There should be sampling and a new variant of the vaccine created fast to prevent this variant of the virus from spreading.
estaseuropano 5y ago
This is just a specific version of the Red Queen of evolution and in no way unexpected. But the virus will keep mutating as much as it spreads, so our best bet is still to vaccinate as widely as possible to contain the spread, thereby reducing chance of mutations. Vaccinated people get still sick but are less likely to infect others, reducing overall spread.
failwhaleshark 5y ago
The reality is antivaxxers and nomaskers are to blame for the entire pandemic, its continuation, and subsequent variant evolution. Contributing factors are lifting restrictions too early, lack of enforcement in underdeveloped and developed countries, and lack of compulsory vaccination. If such measures were taken, the R number would be much less than 1. If gamma circulates worldwide, it might as well be SARS-CoV-3.
vfclists 5y ago
> My understanding is that this is a relatively new and perhaps highly understudied phenomenon It is neither relatively new or understudied. Everyone's favourite "anti-vaxxer", the Godfather of the "Anti-Vaxx Movement", Andrew Wakefield has been saying so for some time. Vaccines: Their Safety, Effectiveness, and Risks https://www.youtube.com/playlist?list=PLbkS7FXQ1321h9H5HdbwPWC3UHeeWjzdM https://www.youtube.com/playlist?list=PLbkS7FXQ1321h9H5HdbwP...

Izkata 5y ago

> One counterpoint that I’ve come across during my own review of the literature, is the idea that imperfect vaccines can cause selective pressure which enhances the fitness of highly virulent pathogens. This is what happened with "Marek's disease", a virus-caused disease in chickens. The vaccine was "leaky" and ended up selecting for a more deadly form, such that now all chickens worldwide have to be vaccinated for it or they'll die if they get infected - which didn't used to be the case. https://en.wikipedia.org/wiki/Marek%27s_disease https://en.wikipedia.org/wiki/Marek%27s_disease

sschueller 5y ago
So does this mean we made this pandemic worse than the one from 1918 when we didn't have a vaccine?
- mlang23 5y ago
  This is very likely. And has already been said by various critics already months ago. But these people were silenced or ridiculed, because it apparently was already decided the vaccines need to be sold.
  - evgen 5y ago
    Completely untrue. The reservoir of selfish unvaccinated individuals is what is providing a place for Covid to hide and mutate. Vax critics were silenced and ridiculed because they are dangerous deceivers who need to be called out and held to account for the consequences of their lies.
    - native_samples 5y ago
      That's not something that's ever been a problem with vaccines before. Even if you have unshakeable faith in this evidence-free perversion of biological theory, nobody was claiming the vaccines will fail without 100% adoption last year when they launched. Their reception would have been rather different if that had been claimed, wouldn't it? So you can either believe this is true, in which case governments and pharma firms deceived people about the nature of the 'vaccine', or you can believe it's false and they didn't. But you can't believe it's true and it's the other people who are deceivers. That makes no logical sense.
      - samus 5y ago
        It's a general issue with every vaccine against an illness that has a reservoir. The reservoir can be other species (birds and various other animals in case of influenza) or it can be human populations that for various reasons have not eliminated the spread of the illness yet (measles in countries that refuse or make it difficult to vaccinate, polio if not completely eradicated yet). In this reservoir the agent has opportunity to mutate, and it can never be excluded that at some point it makes inroads into populations again where it was eradicated before. Global eradication of diseases has been achieved with smallpox and bovine rinderpest precisely because they had no natural reservoir and all vulnerable populations could be vaccinated. With Coronaviruses the situation is not so simple, but it should at least be possible to eradicate the currently relevant variant.
the_mitsuhiko 5y ago
Not all chicken get vaccinated.
yyyk 5y ago
1) All current variations of concern come from mostly unvaccinated countries. Apparently there's a serious issue with immunocompromised individuals and the vaccines may help prevent that: https://www.scientificamerican.com/article/covid-variants-may-arise-in-people-with-compromised-immune-systems/ https://www.scientificamerican.com/article/covid-variants-ma... 2) We can see with SARS and MERS that a more deadly form may actually reduce overall mortality, since the virus can't spread as effectively. However, we haven't had this effect so far.
- erdewit 5y ago
  From the article: > Analysis of samples from the patient showed that the virus evolved rapidly after the plasma therapy, developing mutations that changed how it could infect cells and resist antibodies. Seems to be that the plasma therapy (injecting antibodies) is responsible here.
  - yyyk 5y ago
    There are cases of mutation in immunocompromised preceding plasma therapy, e.g.: https://www.npr.org/sections/goatsandsoda/2021/02/05/964447070/where-did-the-coronavirus-variants-come-from https://www.npr.org/sections/goatsandsoda/2021/02/05/9644470...
- jstanley 5y ago
  > All current variations of concern come from mostly unvaccinated countries. Isn't it more significant not where they emerge (which is by random mutation) but where they do well? And don't they seem to do well in countries that have vaccinated more people? Is it even particularly easy to say where a variant originated? Could the mutations happen multiple times independently?
  - yyyk 5y ago
    >Isn't it more significant not where they emerge (which is by random mutation) but where they do well? Random mutation happens more when we give it more chances, by letting it infect more unprotected people. We'd rather avoid that, so it's also important. >Is it even particularly easy to say where a variant originated? No, but we have gene sampling to help. >Could the mutations happen multiple times independently? They can and sometimes do happen independently.
sampo 5y ago
> This is what happened with "Marek's disease" Marek's disease in chicken is what the PLOS article is about: MDV = Marek's disease virus. > The vaccine was "leaky" and ended up selecting for a more deadly form The researchers of the PLOS article do not claim to know that for certain: "Our data do not demonstrate that vaccination was responsible for the evolution of hyperpathogenic strains of MDV, and we may never know for sure why they evolved in the first place." But this they claim: "But whatever was responsible for the evolution of more virulent strains in the first place (and there may be many causes), our data show that vaccination is sufficient to maintain hyperpathogenic strains in poultry flocks today." https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002198 https://journals.plos.org/plosbiology/article?id=10.1371/jou...

murphyslab 5y ago

> imperfect vaccines can cause selective pressure which enhances the fitness of highly virulent pathogens The number of ways in which we undertaking a natural experiment in viral evolution has been top-of-mind for me as well. But the greater issue in my view is not that the vaccines are imperfect. All vaccines are somewhat imperfect. On its own, I the mRNA vaccines were probably entirely adequate. The problem is that the human population, as a result of policy decisions, will continue to have an immediately-adjacent reservoir of infection [0] with whom we are constantly in contact. I speak, of course, of the large numbers of unvaccinated among us. With vaccinated-to-vaccinated chains of transmission, there's a greater chance that a chain of vaccine-resistant variant will die out because the vaccine both reduces the risk of becoming infected [1] and the risk of transmitting infection [2]. But in a heterogeneous population, with large numbers of unvaccinated individuals, those chains of transmission can go on indefinitely, hopping back-and-forth between the two populations. That's a far greater risk here than the issue of a "leaky" vaccine. A vaccine might "leak" a little bit, yet the probabilities of infection and subsequent infection remain so low that all chains of transmission quickly terminate. Instead, we have a situation where the virus can slip into a separate (reservoir) population where it continues unchecked. That, in my view, is the real risk to furthering infection. [0] https://en.wikipedia.org/wiki/Natural_reservoir https://en.wikipedia.org/wiki/Natural_reservoir [1] https://www.cdc.gov/media/releases/2021/p0607-mrna-reduce-risks.html https://www.cdc.gov/media/releases/2021/p0607-mrna-reduce-ri... [2] https://sporevidencealliance.ca/wp-content/uploads/2021/06/Transmissibility-of-COVID-19-Among-Vaccinated-Individuals_Plain-Language-Summary.pdf https://sporevidencealliance.ca/wp-content/uploads/2021/06/T...

marton78 5y ago
In addition, the vaccines currently in use -- at least in the West -- are either mRNA or vector vaccines containing only parts of the virus (as far as I know only the spike protein from the virus's surface). I would expect them to result in a more specific immunity which is easier for the virus to circumvent, my mutating only its spike protein. Conventional vaccines however, which are more prevalent in the developing world, as well as having gone through COVID, should provide a broader immunity - at least in my half-educated view.

becuzThrowaway 5y ago

My understanding is that there is very little evidence of vaccinated individuals actually transmitting the original ("wild-type") virus, or even the Alpha variant (obviously, Delta/Gamma are potentially different beasts). This was why we in the United States dropped mask mandates for vaccinated individuals. I don't know why the narrative always reverts to "oh, the vaccines just decrease symptoms", a statement unsupported by evidence. EDIT: Before I get downvoted completely into oblivion, take a look at the 90% reduction in infections, both symptomatic and asymptomatic, seen in vaccinated individuals in Israel. https://pubmed.ncbi.nlm.nih.gov/33964222/ https://pubmed.ncbi.nlm.nih.gov/33964222/ I think we can all agree that you can't transmit the virus if you yourself don't get infected.

standapart 5y ago
The amount of abstract certainty present in this comment is truly astonishing. Please just cite the RCT on this.
- becuzThrowaway 5y ago
  https://pubmed.ncbi.nlm.nih.gov/33964222/ https://pubmed.ncbi.nlm.nih.gov/33964222/
  - standapart 5y ago
    This is not an RCT. The work itself makes this very clear, it's observational, based on what we'll call "pseudo-voluntary" testing. Just provide the RCT for your claims-- this is necessary since the vaccine is known to be effective on a symptomatic level.
    - becuzThrowaway 5y ago
      Please provide the RCT that shows that vaccinated individuals have similar levels of infection to unvaccinated individuals. What the RCTs for Pfizer and Moderna showed was that the vaccines reduced the symptomatic infection rate by 95%. But you are misconstruing the language being used if you extend that to say "the vaccine is known to be effective on a symptomatic level". The statement about symptomatic infection just means that it was impractical to have 42,000 people take a COVID nasal swab every day, and therefore they can make no professional scientific statements about the actual rate of infection. But if you are aware of an RCT that actually established the vaccine as being ineffective at preventing infection, I would love to see it. EDIT: And yes, I linked to observational data from Israel (TWICE) that showed real-world effectiveness in preventing both symptomatic and asymptomatic infections.

aranw 5y ago

> imperfect vaccines can cause selective pressure which enhances the fitness of highly virulent pathogens I've wondered this ever since the UK changed it's approach and now that we've got to a state where there is pretty much no restrictions. I think scientists around the world also have this concern with the UK's approach

jsbdk 5y ago
Why would I want to vaccinate if I'm still going to get restricted? I mean the whole deal here was that if we got vaccinated we'd be back to normal life. If that wasn't the case they should've been sincere up front and most of us wouldn't have gotten vaccinated.
- ben_w 5y ago
  Same reason I want to wear a seatbelt even though I’m still restricted by the speed limit: demonstrably lower chances of not merely death but also sub-fatal harm.
  - thirsty-dove 5y ago
    Doesn't seem like a good comparison, because seat belts have been tested for decades and don't seem to be insidiously harmful, whereas VAERS already has an off-the-charts number of reports of deaths and harm. Not a day goes by where I don't hear about somebody dying shortly after getting the vaccine, often in novel ways like described here: https://freewestmedia.com/2021/06/27/surgeon-who-operated-on-young-italian-vaccine-victim-you-have-never-seen-anything-like-this/ https://freewestmedia.com/2021/06/27/surgeon-who-operated-on...
    - ben_w 5y ago
      Even if all of the VAERS reports were both causal (they’re not) and fatal (not even remotely) the vaccine would still be seven times better than the illness. As the reports are overwhelming not about surprise deaths and not causal, the vaccines are somewhere between 170 times better and infinitely better than the disease. > Not a day goes by where I don't hear about somebody dying shortly after getting the vaccine, often in novel ways like described here And how many do you expect by coincidence in an ideal case where there are exactly zero side effects? Because it isn’t going to be zero coincidental deaths when there are 3.79 billion vaccination events. Not even zero per day.

Pyramus 5y ago

A couple of comments: > [...] vaccines reduce the chance of severe (symptomatic) illness but do not necessarily prevent infection and transmission. My understanding is that at least the RNA vaccines are sterilizing when titers peak, i.e. in the first weeks (months?) after full vaccination. This is due to the presence of a certain type of antibody in the mucosa of the respiratory tract. We also know that levels decrease over 6-12 months, at which point you can get infected, but illness will be mild due to T cell activity. (assuming the immune system of a young, healthy person). > My understanding is that this is a relatively new and perhaps highly understudied phenomenon. I don't have the impression it's understudied. With the widespread prevalence of genetic sequencing we have a pretty good understanding of the mutation activity. Once a variant has an evolutional advantage it is studied quite closely whether it is a fitness escape, an immune escape or both. E.g. Delta is mostly a fitness escape but fortunately only a slight immune escape. > or just trade relevant links with others who are diving into primary sources as a way to form an educated and well rounded opinion. The best resource I can give you is a German podcast with two of Germany's leading virologists [1]. Personally listening to experts in their field in a long form interview has been orders of magnitude more insightful. It's one thing to read an article in Vanity Fair whether the virus has escaped from a lab, it's a totally different thing to listen to an expert that actually knows how to do gain of function research. Maybe it's worth translating the transcriptions? [1] https://www.ndr.de/nachrichten/info/podcast4684.html https://www.ndr.de/nachrichten/info/podcast4684.html

trhway 5y ago

>the widespread observations that COVID-19 vaccines reduce the chance of severe (symptomatic) illness but do not necessarily prevent infection and transmission. that puts worksplace/etc. mandates into spotlight as their main rationale is to prevent the spread, ie. supposedly "it is not for you, it is for the others". So, it sounds like as a result of such mandates we may end up in a situation where the only people spreading virus at work/hospitals/government offices/etc. would be the ones with a highly virulent variety less susceptible to vaccines.

dot1x 5y ago

> That being said, IMO there seems to be a growing public opinion that unvaccinated individuals are to blame for the increasing dominance of variants of concern (delta, gamma, etc). This is no coincidence. The media has been directed to _not_ blame vaccines for ANYTHING, as doing so would negatively impact their narrative. It's well known that people vaccinated with leaky vaccines are the breeding ground for super-bugs, especially between they get their 1st and 2nd dose. The problem? Since their immune system has been trained for only the spike protein, they will be at an immune disadvantage once the variant learns how to completely circumvent the vaccine-induced immune response (and trust me, that's where we're going with all these variants, it's no coincidence Pfizer is prepping the 3rd shot). Once SARS-COV-2 has mutated enough to evade the current vaccine, we're going to have a resurgence of hospitalization and severe covid cases all around the world, but this time in VACCINATED people. Since their immune system has been primed by an incomplete vaccine, it will not generate multi-epitope antibodies any longer as it'll think "it got this handled" due to previous (incomplete) antibodies. Of course, the media will blame the "unvaxxed", just as they started doing right now. More lockdowns will commence, more vaccines every few months (with compounding risks). Oh, did I mention that subsequent vaccines will be less effective the more you get vaccinated, because your body is already primed and it'll produce the antibodies from the 1st vaccines? Look into "Original Antigenic Sin" or OAS.

dot1x 5y ago
Downvote as much as you want, the truth ain't changing :)
- drdeca 5y ago
  I didn’t downvote the original comment, but my understanding of the social conventions here is that complaining about downvotes is frowned upon.
yyyk 5y ago
'It's well known that people vaccinated with leaky vaccines are the breeding ground for super-bugs, especially between they get their 1st and 2nd dose.' It's well known immunocompromised people are breeding grounds. One way to avoid that is vaccinating them early. 'it will not generate multi-epitope antibodies any longer as it'll think "it got this handled" due to previous (incomplete) antibodies.' The immune system knows to benchmark existing antidotes. If the spike antibody isn't enough it will stop producing it.

lmilcin 5y ago

> As other commenters have noted, this case study further supports the widespread observations that COVID-19 vaccines reduce the chance of severe (symptomatic) illness but do not necessarily prevent infection and transmission. Your argument that the vaccine stops only symptoms and not the infection is false. If that was true, we would not see countries that practically eradicated the virus instantly after vaccination (like Israel). The virus would still be spreading and infecting people, and those unvaccinated would still be getting seriously ill. > That being said, IMO there seems to be a growing public opinion that unvaccinated individuals are to blame for the increasing dominance of variants of concern (delta, gamma, etc). The vaccines have proved to be effective preventing infection from the original strains. If people have vaccinated then, it is likely we would have been done with the virus. Now, there were not enough vaccine doses to vaccinate everybody in the world in time, so a strain developing in a poor country could still reach western world. So it may not have been possible to prevent delta completely.

pigeonhole123 5y ago
Coparing Jordan and Israel, their new cases and death graphs look very similar. Israel has a 60% vaccination rate and Jordan has 20%. Where did you get this "instantly eradicated" idea from?
effie 5y ago
> countries that practically eradicated the virus instantly after vaccination (like Israel) Source for this absurd claim?
- lmilcin 5y ago
  It is not an absurd claim. The statistics are available to everybody. Israel implemented vaccinations efficiently and very quickly their infection rates dropped close to zero. I live in Poland and same thing happened here. Now the infection rates grow again because the current vaccination rate and vaccine themselves are not enough to protect.
  - glandium 5y ago

nikolay 5y ago

Many young people have still a low chance of severe course of the disease but they are pushed to get vaccinated. My issue with the disease is not the severe course, which some people are pretty well protected from, but the lasting tissue and organ damage going thru the infection with or without a vaccine. I yet have to see a study showing that vaccines prevent such damage. We will have huge epidemics of CVDs after this is over as nobody really pays now close attention to people who pass thru the disease with or without symptoms.

scotty79 5y ago
It is possible that covid gives you brain damage even if you have mild symptoms https://www.businessinsider.com/covid-19-survivors-gray-matter-brain-tissue-long-term-study-2021-6?IR=T https://www.businessinsider.com/covid-19-survivors-gray-matt... Not sure if vaccines prevent any of this. They surely prevent damage by reducing infection rates in fully vaccinated, but not sure if they can save you from damage, same way they are saving you from death if you contract the virus anyways. https://www.medrxiv.org/content/10.1101/2021.07.13.21260393v1 https://www.medrxiv.org/content/10.1101/2021.07.13.21260393v...
- nikolay 5y ago
  My point is that many restrictions are removed for fully-vaccinated people, i.e. the exposure of these people will increase, i.e. the chance of getting the infection, even if it doesn't take you to the hospital, greatly increases. Even if it's a small percentage, this means many people will get lasting damage. To me, vaccination status should not mean you can take your face mask off - first, you can still get stick, and, second, you can still bridge two sick people even better as you're less likely to show symptoms when you still carry the virus and exhale it without the mask.
  - samus 5y ago
    It's of course not ideal that restrictions are unduly waived. But it is also recognized that many won't consider taking the vaccine because they don't see how doing so contributes to end the pandemy. Luring them with incentives like entry to bars without testing, or positive monetary rewards, changes the decision making process though. But many places maintain restrictions like mask wearing or mandatory testing for a reason.

maxerickson 5y ago

All vaccines are imperfect. The mRNA vaccines are relatively effective. The strains that are spreading were first detected well before widespread vaccination. Widespread vaccination can increase the relative fitness of an existing strain of course, if it more or less eradicates less infectious strains.

Gravityloss 5y ago

The MRNA vaccine was developed fast, it's the testing that took a long time. There should be sampling and a new variant of the vaccine created fast to prevent this variant of the virus from spreading.

estaseuropano 5y ago

This is just a specific version of the Red Queen of evolution and in no way unexpected. But the virus will keep mutating as much as it spreads, so our best bet is still to vaccinate as widely as possible to contain the spread, thereby reducing chance of mutations. Vaccinated people get still sick but are less likely to infect others, reducing overall spread.

failwhaleshark 5y ago

The reality is antivaxxers and nomaskers are to blame for the entire pandemic, its continuation, and subsequent variant evolution. Contributing factors are lifting restrictions too early, lack of enforcement in underdeveloped and developed countries, and lack of compulsory vaccination. If such measures were taken, the R number would be much less than 1. If gamma circulates worldwide, it might as well be SARS-CoV-3.

vfclists 5y ago

> My understanding is that this is a relatively new and perhaps highly understudied phenomenon It is neither relatively new or understudied. Everyone's favourite "anti-vaxxer", the Godfather of the "Anti-Vaxx Movement", Andrew Wakefield has been saying so for some time. Vaccines: Their Safety, Effectiveness, and Risks https://www.youtube.com/playlist?list=PLbkS7FXQ1321h9H5HdbwPWC3UHeeWjzdM https://www.youtube.com/playlist?list=PLbkS7FXQ1321h9H5HdbwP...