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AstraZeneca Scientist Says Delta Variant Makes Herd Immunity Impossible

84 points by lnyan 5y ago

kalaido 5y ago
Lol. I thought the vax would fix every problem? Isn't that what we were promised?
fidesomnes 5y ago
My favorite new news was Fauci telling all of you to get booster shots.
robertwt7 5y ago
But isn't vaccine supposed to make the virus less severe? I've seen many of my relative or friend of a friend who caught the virus weeks after getting the vaccine. Most of them have less severe effect, some of them still have critical condition.. At this point if even vaccine is not effective, then we're not sure how to kick this virus ass anymore I'm still pro to get vaccine btw, I'm getting it once I am eligible :/
- jhayward 5y ago
  Yes, the vaccines are still very effective against severe disease. It is transmissibility that's changed dramatically.
- tharkun__ 5y ago
  That is exactly what the article says (25x less likely to have a severe case/die). The point is the transmissability (as also recently published by the CDC). You yourself get a milder case if you're vaccinated and catch Delta. But you can now still transmit it to children that can't be vaccinated (and who potentially are in a risk group), friends that have a contra-indication to vaccination but are in a risk group etc.
- wjossey 5y ago
  Many of the vaccines are effective against the delta, but they do not serve as a firewall to stop the spread of infection within a community. As a simple example, imagine you have a community of 100 people. 1 person is infected, 98 are vaccinated, and 1 is uninfected and not vaccinated. Ideally the 98 people who are vaccinated don’t contract the virus, and do not serve as vectors of spread for that one unvaccinated person. In essence, you make it so the one infected person has to come in contact with the unvaccinated person. With delta, the 98 vaccinated people are astronomically less likely to die or become severely ill from covid; however, they still can contract and pass along the virus… Which can eventually make its way to the one unvaccinated person at the end of the chain. So, vaccines are great. Vaccines work. These vaccines are awesome for how fast they were produced. But they aren’t able to serve as barriers of protection for the unvaccinated in a way other vaccines for other diseases.
labster 5y ago
I guess nature perfected what the Wuhan lab could not.
wejick 5y ago
I can't open the article, it seems redirected to insider.com/asia
greesil 5y ago
What about the intranasal vaccine?
- jhayward 5y ago
  That's what I want to know. A mucosal vaccine would be a very effective counter to the ramped up viral load and shorter incubation period that delta has brought.
anonuser123456 5y ago
Shouldn’t there be a “with existing vaccines” be attached to that? Delta was particularly infectious due to some mutations, but are those mutations antithetical in some way to antibody production? Why can’t b-cells just update their response and block that pathway with a new vaccine? My understanding is this was always expected to be whack a mole with the virus anyway. All other endemic coronavirus reinfect people.
- wonderwonder 5y ago
  We have 45% of Americans refusing to get a vaccine now, imagine the push back if we are attempting to get people to take a new one every 6 months. I don't have a better answer I just know that absolute chaos is down that road.
  - anonuser123456 5y ago
    I don’t think it’s that bad. Remember that children < 12 still can’t get it, which is a good chunk of people. Also, some people are not antivax, they are afraid of new mRNA technology. When the technology has had more time to bake, they will feel more comfortable. Finally, Novavax will be coming online soon. That should help with some of the mRNA skeptics.
    - eigen 5y ago
      > Also, some people are not antivax, they are afraid of new mRNA technology. then they can get the Janssen (aka Johnson & Johnson) vaccine which is not based on mRNA but an Adenovirus vector.
      - halfjoking 5y ago
        It’s viral vector which isn’t a traditional vaccine. Viral vector has only been used before for Ebola. All US vaccines execute custom RNA code that was spliced from the real virus. Viral vector just gets that code in the cell by a different method.
      - 5y ago
greesil 5y ago
What's the R0 in a vaccinated population?
- baby 5y ago
  Are there scientific papers out there that are worth reading on the road ahead with what we know about the delta variant? I remember Neil Ferguson’s paper early 2020 that was a goldmine of information and predicted that we would have to do lockdowns on and off for a year and a half til the vaccine. It was pretty spot on.
- gibba999 5y ago
  It depends on what other measures they take. A big part of the problem is everyone said "We're vaccinated, so we're done." That put enormous evolutionary pressure for the virus to learn to hop the vaccine.
ekianjo 5y ago
Isn't heard immunity impossible anyway with current vaccines regardless of the strain, since vaccinated people can still carry and transmit the virus? Herd immunity only works if you have sterilizing vaccines.
- davidcbc 5y ago
  Vaccinated people are much less likely to carry the virus.
  - ekianjo 5y ago
    Not at all. They are much less likely to get severe symptoms, which is not at all the same thing. There are several studies already in several countries showing that with Delta the viral load between infected vaccinated people and unvaccinated people is identical.
- vajrabum 5y ago
  Sterilizing or no herd immunity works if you can push R0 below 1. Below 1 fewer and fewer people get infection and the cycle stops.
  - ekianjo 5y ago
    Yeah but (current) vaccines are not stopping the transmission anyway, so they don't decrease R at all. That's been abundantly demonstrated already. (which is what Israel is finding out now after vaccinating almost everyone).
    - vajrabum 5y ago
      The vaccine does slow the rate of infection even Delta, but 59.9% is the current percentage of fully vaccinated in Israel and that's good but it's far from everyone. Very far given the infectiousness of Delta.
- toss1 5y ago
  Actually, herd immunity works if it reduces the R0 to less than 1. Obviously, the extinction happens a lot faster wit a vaccine as you describe that reduces R0 to zero, but an exponential decline will still result in extinction (barring other reservoirs).
epistasis 5y ago
We had a chance to keep a new disease under control, but it's increasingly looking like humanity blew that chance. There was definitely political interference in the US, and other places, people prioritizing the success of their favorite politicians over fighting a common enemy, but I'm not sure if we would have succeeded in fighting this back even if the US and other nations with political interference had not had the traitorous attitudes. Makes me realize how lucky we were with the first SARS and with MERS.
- gfodor 5y ago
  Delta’s rapid evolution and plausible defeat of the vaccine which was rolled out incredibly fast, on the back of unprecedented economic lockdowns implies to me we didn’t stand a chance absent a global totalitarian regime just imprisoning everyone in their homes for a year by force.
  - mensetmanusman 5y ago
    It would still spread in wildlife though, so it would have to be a forever prison.
    - epistasis 5y ago
      SARS1 and MERS also lived in animals, but we were able to defeat those. SARS2 is definitely a much more difficult foe, and counterfactuals are always hard to establish, but I think we came pretty close to fighting it back. And we might still! I honestly have some hope for eventual elimination of the common cold (actually many different diseases, not one) to a large degree. Vaccine technology is advancing at a ridiculous pace these days. There is so much we don't know about immunology, but we are also learning so fast and biotech is accelerating too.
  - gibba999 5y ago
    ... or using N95-equivalent masks and mild social distancing ... What's scary is gamma through omega.
rubyist5eva 5y ago
Already got it, recovered, don't give a s*it about this virus anymore. Give me my freedom back before I come and take it.
wombatmobile 5y ago
What is the nature of the delta mutations ie what mechanism/a make it more infectious?
- deleted 5y ago
  [deleted]
- toss1 5y ago
  The measured viral load is substantially higher (e.g., 1000x in some studies) vs the original strain, and it is suspected, but not proven (afaik) that this translates to more exhaled virus. What is known is that the virus ramps up in the infected people more quickly, and stays infectious longer, so for sure, each person is infectious for more days on both sides, increasing infectious opportunities. In the vaccinated population with breakthru Delta cases, the viral load initially approaches the load of unvaxed people in the first few days after becoming detectable, but then falls off much more rapidly.
  - poisonarena 5y ago
    Can people who had the OG Covid(me) get it and get sick again? or are they more or less okay?
    - 6nf 5y ago
      There are only handful of verified cases of people getting covid more than once. It's extremely rare from what I can tell.
      - toss1 5y ago
        Both are fairly rare, but the latest data I've seen shows both 1) weaker and faster decaying immune response in previously infected people vs immune response from vaccine, and 2) previously infected people getting infected at abt 2X the rate of fully vaccinated people. (Sorry, no ref links on hand at the moment)
dcolkitt 5y ago
Here's my question. Current CFR for vaccinated individuals is under 0.05%. At that point does it matter if Covid's endemic? I think the problem is we're all anchored to Covid from early 2020, which was definitely a huge danger. So we hear that there's still community spread, and fly into a panic shutting everything down. But at 0.05% CFR, it's barely more dangerous than seasonal flu. If Covid in February 2020 had 0.05% would we even have done anything about it?
- newsbinator 5y ago
  Seasonal flu typically passes and has no lasting or permanent effects, in most cases. What % of people get Covid and are noticeably operating at less than 100% thereafter? What % are operating at less than 70% thereafter? Low CFR merely means you didn't die. It doesn't mean Covid didn't break you.
  - dcolkitt 5y ago
    Long influenza absolutely does exist. At least to the same standard of self reported evidence that is being used to report long Covid. [1]https://time.com/5915616/long-flu-1918-pandemic/ https://time.com/5915616/long-flu-1918-pandemic/
  - swiley 5y ago
    I've known multiple people that permanently lost their sense of taste after a bad flu.
- throwawaysea 5y ago
  COVID IFR was always low. The CDC planning scenarios (https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena...) consistently showed low IFR for those under 50 even mid 2020 in their earlier updates. However this was obfuscated by alarmist journalism and divisive politics, as well as people confusing CFR and IFR. COVID wasn’t that dangerous ever, unless you were immunocompromised or elderly, or unless your measure of danger is based on a high risk aversion. There is the possibility of rare lingering side effects. However studies show that the worst side effects, like ARDS, primarily affect those who are obese or vitamin D deficient. You could make an argument that it’s the individual’s’ responsibility to manage their own risks and vulnerability for that. Alternatively you could say that those comorbidities are common enough that they require society wide management.
anonymouswacker 5y ago
All of the anti-vaxxers were right this time around. What a complete clusterfuck.
- midrus 5y ago
  No, they're not. It would be a lot worse without the vaccines. Just compare how things are going on countries where vaccination is not happening vs countries that have a high population already vaccinated and you will see how ridiculous your comment is. Antivax and comments like this only makes things worse.
  - dazag 5y ago
    Not listening to a*holes blindly accepting only one side of the narrative, at least open your eyes to the opposite, or you will never realize when you're right or wrong. It is just science man, it is call antithesis.
    - midrus 5y ago
      What part of more people dying because not having had the vaccine than people die from side effects of having had it? I suppose that's not science to you because it's not in a tweet.
  - fidesomnes 5y ago
    It isn't a vaccine if you can still get covid and or spread it to others. It is an MRNA gene therapy with a covid viral load to boot immune system response by attaching itself to your DNA.
vimy 5y ago
Since the vaccines don’t seem to stop transmission their only use is to protect the ones who take it. So there is no need anymore for vaccine passports and forcing people to take it. Unless I’m missing something?
- throwawaysea 5y ago
  They don’t stop transmission but reduce its likelihood significantly. It seems someone who is vaccinated and very ill can be very infectious but generally vaccinated people are unlikely to infect others (reduced observed R0).
- finolex1 5y ago
  Vaccines definitely reduce transmission, just to a slightly smaller extent for the Delta variant. The CDC's messaging on this issue has been atrociously bad.
- selcuka 5y ago
  The vaccines don't stop transmission, but they still radically reduce it. Pfizer is 94% effective [1] in reducing transmissions of the original strain. Even with the delta variant it is still 64% effective: [1] https://www.businessinsider.com.au/israel-may-reimpose-coronavirus-restrictions-as-delta-variant-fuels-surge-2021-7 https://www.businessinsider.com.au/israel-may-reimpose-coron...
- shock-value 5y ago
  The do vastly lower the rate of transmission. That could translate into lower peak hospital utilization (even not accounting for their ability to prevent illness) which is good for everyone. I do agree that this thing is going to spread in an unbounded manner regardless of what we do now though.
- kyrra 5y ago
  Total guess: Slows down transmission. Those that are asymptomatic should have a lower viral load, which results in fewer cases.
- MereInterest 5y ago
farmerstan 5y ago
This doesn’t make sense. People who are infected by delta variant will become immune to delta variant. So if they are infected and it runs it’s course through the human population, people will get herd immunity from it. Or if we create a vaccine for delta variant similar thing should happen. But we also already know that we don’t achieve sterilizing immunity from coronavirus even with previous infection or vaccine. So it was never the case that we couldn’t stop transmitting the disease.
- nevir 5y ago
  I don't believe it's actually the case that once you are infected by the delta strain your body has lasting immunity to that same strain. It looks like that also is affected by age and other constraints: https://www.nature.com/articles/d41586-020-00502-w https://www.nature.com/articles/d41586-020-00502-w
  - base698 5y ago
    The vaccine is a single antigen. A live virus has many antigens. It makes sense your body would have more attacks if naturally infected.
  - farmerstan 5y ago
    To not have lasting immunity to the same strain is anti-science. We already know that people who were previously infected by covid are immune to many different variants. To think otherwise would be illogical. Even SARS patients from 2003 have immunity to SARS 18 years later.
- paulmd 5y ago
  > People who are infected by delta variant will become immune to delta variant "people who were exposed to H1N1 flu last year will become immune to it, so once it runs its course people will get herd immunity from it and the virus will die out". that's not how it works. What the scientist is saying here is that it's mutating fast enough that by the time we start to approach "herd immunity" (via vaccination or just exposure) it's mutated and the herd immunity is no longer effective against the new variant. So yeah you're immune to the strain from last year, but it doesn't do anything against this year's strain. and on top of that Delta is literally so infectious that it'll just about spread right through the existing vaccines. The vaccines were 98% effective against the initial strain, now Pfizer/Moderna are 88% effective, which means you have 6x as much spread (at an epi/population level), on top of a strain that is, itself, 2.5x as transmissible. So now we have to hit a much higher level of vaccination (near-100%) to get the reproduction number under 1.0. And then you've got the other vaccines - some early studies indicated Astra-Zeneca is only about 60% effective (!) which means even with 100% vaccination that vaccine could not stop the spread. Best-case scenario you have to get those people a booster shot of something else - and the clock is still ticking, it is still mutating and in another year the effectiveness of all the existing vaccines will be even lower. And on top of that, those are only the "severe illness" numbers, the "mild/moderate" illness numbers are higher, vaccinated people still spread an appreciable amount, and it's spreading through kids very aggressively now (funny how HN told me just last week that kids were immune and we could reopen schools...) In short if you want vaccines to actually work and reach herd immunity - you have to slow it down enough with containment measures to slow down the rate of mutation. Because if you just let people get exposed, every exposed person is another chance for the virus to mutate, and it's mutating fast enough that by the time we get everyone vaccinated, the virus will have mutated enough the vaccines are no longer very effective. (And reality check - we've barely got a start on vaccinating the global population, which is what you really have to do to control it. Vaccines are flowing like water in the US and Europe, and to a lesser extent in other developed nations, but in a lot of the world you just can't get a fucking vaccine even if you want one. A few months ago the number was something like 140 countries hadn't even gotten a single dose of vaccine yet.) Realistically that is no longer possible at this point. People are done with quarantine and social distancing and 40% of the country won't get vaccinated even when they're free and readily available. And now it's mutated to become several times as transmissible - that's game over. It's over, it's going to become endemic, it's a foregone conclusion at this point.
deleted 5y ago
[deleted]
johnp314 5y ago
Has anyone looked at the Johns Hopkins COVID map and considered Sweden? Last year they were the country all the lockdown experts vilified (and libertarians envied). Today, Aug 12 2021, among most all western nations they show essentially no delta-bump. How do all you experts blaming anti-vaxers and AstraZeneca scientists looking at Israel explain this data point? What has given Sweden this apparent immunity from delta? It's annoying when inconvenient reality gets in the way of our theoretical science.
- glangdale 5y ago
  They had a ton of COVID cases (1M, in a population of 10M!) and have vaccinated heavily. They're also doing a lot of the social distancing things that they initially avoided. Vaccination does reduce the chance of spreading the virus. Having 10% of the country get the natural variant and 45% fully immune, plus still doing the social distancing stuff, and requiring negative COVID tests for those entering the country, seems like a pretty good way of keeping delta under control.
  - nradov 5y ago
    As in every other country the case count is way lower than the actual number of infections. Most infected people never get tested or officially counted. They estimate that about 33% of Swedes had been infected by May 2021 and presumably the number is higher now. https://www.news-medical.net/news/20210714/e2809cHerd-immunitye2809d-not-responsible-for-Swedene28099s-control-of-COVID-19-say-researchers.aspx https://www.news-medical.net/news/20210714/e2809cHerd-immuni... As a comparison point the CDC estimates that about 36% of Americans have been infected. https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burd...
    - glangdale 5y ago
      Yeah, that would be even more consistent with the idea that there's a combination of natural resistance (if not immunity) from the first form of the virus (I think you can get again) as well as resistance for vaccination. It's not going to be 33% + 45% because there'd be overlap in the categories, but that's probably a pretty high rate of resistance. Couple that with the fact that the Swedes aren't acting completely stupid and are doing a pretty good job of voluntary distancing (not to mention border control) and it seems like the numbers are pretty easily explained. Quite the cost to get there...
glangdale 5y ago
As far as I can tell the conclusions we're going to have to draw are: 1) We need to keep using all strategies - including masking, social distancing, and targeted lockdowns - to reduce large scale spread of the virus. If we don't, we're going to be playing "new variant whack-a-mole" until the end of time. 2) Vaccination is critical to make the above task easier but it's not enough it itself. There seems to be a lot of evidence that it reduces chance of passing it on and the severity of the cases, but it's clearly not enough by itself (see Israel, although the remaining unvaccinated population is a big factor anywhere in passing COVID on). We're also going to have to start kicking the asses of the pointlessly vaccine-skeptical through harsh restrictions and denial of things. In Australia, once we have universal access to the vaccine, I would be quite keen to see vaccine refusers not treated for free if they do get COVID - I'd support a "HECS"-like scheme for people who get avoidable diseases like this, including the government getting to sell your house when you die to recoup costs. 3) There's a pile of stuff we don't know about the long-term effects of COVID-19 and some ominous indications that it's Really Not Good. I don't want to get into a case-by-case with a bunch of self-appointed Internet Experts about this but there's a lot of medical opinion out there that long COVID is real and serious (particularly on the neurological side). We don't know how bad it really is because no-one has had COVID for more than 2 years. Having participated in the care of multiple relatives over the years with dementia, one thing that chills me is the prospect that COVID will lead to even a slight uptick in the chance of getting Lewy body dementia or Parkinson's. That's a fucking public health tsunami. We also don't know much about the effects of lockdown, etc. but the picture seems to be complex and indecisive. All the anti-lockdown people going on about suicides and depression apparently think the only source of suicide and depression in a massive pandemic where people are losing folks dear to them and are terrified of getting a debilitating disease is because they are locked down. As usual, it's the typical overreach of the Internet Expert. Normal is a very long way off. The implications of COVID being 'endemic' certainly aren't what most people casually tossing the word around think they are, and magical thinking about 'living with the virus' isn't going to make long COVID go away.
- nradov 5y ago
  It's too late to prevent large-scale spread of the virus. That already happened and it's now endemic worldwide. We don't have a time machine. You obviously can't expect most people to continue tolerating masking, social distancing, and lockdowns indefinitely with no clear, achievable exit criteria. That would be absurd and people in free societies won't comply regardless of the potential consequences. You can complain that they're being irresponsible and putting others at risk but that won't change the reality. At some point we'll have to accept the risk and move forward with normal life. Fortunately the vaccines are very effective at preventing deaths.
rich_sasha 5y ago
I wonder how Covid compares to the bubonic plague. It remains endemic in some parts of Asia (so not disappeared), it is zoonotic (rodents, even cute squirrels in some parts of the US), killed off something like 1/3rd of Europe’s population, and... is generally a non-event nowadays. Not a pretty comparison if valid, of course. But that was what would be a nightmare scenario for Covid: letting the disease rip through a populous continent. And yet it burnt out eventually, over the course of 7 years, according to Wikipedia. For the most part, anyway. Bubonic plague outbreaks continued for centuries, but never again was there a continent-wide pandemic.
- hellisothers 5y ago
  Isn’t that partially because some people had better resistance to it and the survivors passed it on? https://www.studyfinds.org/bubonic-plague-human-immunity/ https://www.studyfinds.org/bubonic-plague-human-immunity/
  - rich_sasha 5y ago
    Maybe. This could happen with Covid too. Not a pretty scenario! But better than deadly-remains-forever.
- candiodari 5y ago
  Is this a trap question? I mean you can make 2 cases. Firstly the noncontroversial part: covid is a virus, bubonic plague is a bacterium. In the covid case, infected people infect others. Stay away from people, especially in restaurants (so, probably, eating near an infected person is a strong vector), and there isn't much chance of infection. In the case of bubonic plague: enter a building where an infected person had a shit 2 months before ... there's a decent chance you get infected. It's a world of difference. Objects are safe, with covid. Streets are safe. Beds are safe. Public toilets are safe. Public toilets would be a death trap with the bubonic plague. You ignore age? They're comparable in death rate. You only count people under 40 (life expectancy, without bubonic plague, was only about 30-40 years when bubonic plague got it's big moment). So if you compare that to what covid does to people <40, it's much less than the mildest flu ... Let's say you relax that by a lot and say, no people live to 70 in the 14th century, about double the real figure ... covid is about an average flu. So ... like everything, it depends. If you make a case based on years lost, covid is an exceptionally deadly flu, but less than 1% as bad as the bubonic plague. If you make a better comparison, and compare Covid to Tuberculosis, today, then for the first 4 months it got to about half as bad as TBC, then fell off a cliff. If you take an average over a year, TBC wins on all fronts: people infected, people killed, years of life destroyed, ... well, except on dollars spent. BUT covid kills many rich old people in the west. Tuberculosis kills young poor adults, mostly in the third world. Tuberculosis produces orphans. Not that I don't think rich people in the west they have right to a few more years, they very much do. But you want to help humanity, it's the wrong target. So Covid only really wins from even contemporary diseases in the "dollars resisting the deaths" department.
loftyal 5y ago
Wont we achieve herd immunity via natural infecion then? Unless the virus starts to become like flu, which evades the the natural immunty very easily.
- bananapub 5y ago
  if the problem is that the immune response drops too low to prevent infection then there may be no herd immunity from that either, it can just cycle around.
- deleted 5y ago
  [deleted]
- nradov 5y ago
  With highly contagious diseases, herd immunity is kind of a meaningless concept. Eventually close to 100% of people get infected.
bartimus 5y ago
It seems they are confusing herd immunity with complete eradication? Most likely the virus will become endemic. We've already achieved a level of herd immunity.

84 points by lnyan 5y ago

kalaido 5y ago

Lol. I thought the vax would fix every problem? Isn't that what we were promised?

fidesomnes 5y ago

My favorite new news was Fauci telling all of you to get booster shots.

robertwt7 5y ago

But isn't vaccine supposed to make the virus less severe? I've seen many of my relative or friend of a friend who caught the virus weeks after getting the vaccine. Most of them have less severe effect, some of them still have critical condition.. At this point if even vaccine is not effective, then we're not sure how to kick this virus ass anymore I'm still pro to get vaccine btw, I'm getting it once I am eligible :/

jhayward 5y ago
Yes, the vaccines are still very effective against severe disease. It is transmissibility that's changed dramatically.
tharkun__ 5y ago
That is exactly what the article says (25x less likely to have a severe case/die). The point is the transmissability (as also recently published by the CDC). You yourself get a milder case if you're vaccinated and catch Delta. But you can now still transmit it to children that can't be vaccinated (and who potentially are in a risk group), friends that have a contra-indication to vaccination but are in a risk group etc.
wjossey 5y ago
Many of the vaccines are effective against the delta, but they do not serve as a firewall to stop the spread of infection within a community. As a simple example, imagine you have a community of 100 people. 1 person is infected, 98 are vaccinated, and 1 is uninfected and not vaccinated. Ideally the 98 people who are vaccinated don’t contract the virus, and do not serve as vectors of spread for that one unvaccinated person. In essence, you make it so the one infected person has to come in contact with the unvaccinated person. With delta, the 98 vaccinated people are astronomically less likely to die or become severely ill from covid; however, they still can contract and pass along the virus… Which can eventually make its way to the one unvaccinated person at the end of the chain. So, vaccines are great. Vaccines work. These vaccines are awesome for how fast they were produced. But they aren’t able to serve as barriers of protection for the unvaccinated in a way other vaccines for other diseases.

labster 5y ago

I guess nature perfected what the Wuhan lab could not.

wejick 5y ago

I can't open the article, it seems redirected to insider.com/asia

greesil 5y ago

What about the intranasal vaccine?

jhayward 5y ago
That's what I want to know. A mucosal vaccine would be a very effective counter to the ramped up viral load and shorter incubation period that delta has brought.

anonuser123456 5y ago

Shouldn’t there be a “with existing vaccines” be attached to that? Delta was particularly infectious due to some mutations, but are those mutations antithetical in some way to antibody production? Why can’t b-cells just update their response and block that pathway with a new vaccine? My understanding is this was always expected to be whack a mole with the virus anyway. All other endemic coronavirus reinfect people.

wonderwonder 5y ago
We have 45% of Americans refusing to get a vaccine now, imagine the push back if we are attempting to get people to take a new one every 6 months. I don't have a better answer I just know that absolute chaos is down that road.
- anonuser123456 5y ago
  I don’t think it’s that bad. Remember that children < 12 still can’t get it, which is a good chunk of people. Also, some people are not antivax, they are afraid of new mRNA technology. When the technology has had more time to bake, they will feel more comfortable. Finally, Novavax will be coming online soon. That should help with some of the mRNA skeptics.
  - eigen 5y ago
    > Also, some people are not antivax, they are afraid of new mRNA technology. then they can get the Janssen (aka Johnson & Johnson) vaccine which is not based on mRNA but an Adenovirus vector.
    - halfjoking 5y ago
      It’s viral vector which isn’t a traditional vaccine. Viral vector has only been used before for Ebola. All US vaccines execute custom RNA code that was spliced from the real virus. Viral vector just gets that code in the cell by a different method.
    - 5y ago

greesil 5y ago

What's the R0 in a vaccinated population?

baby 5y ago
Are there scientific papers out there that are worth reading on the road ahead with what we know about the delta variant? I remember Neil Ferguson’s paper early 2020 that was a goldmine of information and predicted that we would have to do lockdowns on and off for a year and a half til the vaccine. It was pretty spot on.
gibba999 5y ago
It depends on what other measures they take. A big part of the problem is everyone said "We're vaccinated, so we're done." That put enormous evolutionary pressure for the virus to learn to hop the vaccine.

ekianjo 5y ago

Isn't heard immunity impossible anyway with current vaccines regardless of the strain, since vaccinated people can still carry and transmit the virus? Herd immunity only works if you have sterilizing vaccines.

davidcbc 5y ago
Vaccinated people are much less likely to carry the virus.
- ekianjo 5y ago
  Not at all. They are much less likely to get severe symptoms, which is not at all the same thing. There are several studies already in several countries showing that with Delta the viral load between infected vaccinated people and unvaccinated people is identical.
vajrabum 5y ago
Sterilizing or no herd immunity works if you can push R0 below 1. Below 1 fewer and fewer people get infection and the cycle stops.
- ekianjo 5y ago
  Yeah but (current) vaccines are not stopping the transmission anyway, so they don't decrease R at all. That's been abundantly demonstrated already. (which is what Israel is finding out now after vaccinating almost everyone).
  - vajrabum 5y ago
    The vaccine does slow the rate of infection even Delta, but 59.9% is the current percentage of fully vaccinated in Israel and that's good but it's far from everyone. Very far given the infectiousness of Delta.
toss1 5y ago
Actually, herd immunity works if it reduces the R0 to less than 1. Obviously, the extinction happens a lot faster wit a vaccine as you describe that reduces R0 to zero, but an exponential decline will still result in extinction (barring other reservoirs).

epistasis 5y ago

We had a chance to keep a new disease under control, but it's increasingly looking like humanity blew that chance. There was definitely political interference in the US, and other places, people prioritizing the success of their favorite politicians over fighting a common enemy, but I'm not sure if we would have succeeded in fighting this back even if the US and other nations with political interference had not had the traitorous attitudes. Makes me realize how lucky we were with the first SARS and with MERS.

gfodor 5y ago
Delta’s rapid evolution and plausible defeat of the vaccine which was rolled out incredibly fast, on the back of unprecedented economic lockdowns implies to me we didn’t stand a chance absent a global totalitarian regime just imprisoning everyone in their homes for a year by force.
- mensetmanusman 5y ago
  It would still spread in wildlife though, so it would have to be a forever prison.
  - epistasis 5y ago
    SARS1 and MERS also lived in animals, but we were able to defeat those. SARS2 is definitely a much more difficult foe, and counterfactuals are always hard to establish, but I think we came pretty close to fighting it back. And we might still! I honestly have some hope for eventual elimination of the common cold (actually many different diseases, not one) to a large degree. Vaccine technology is advancing at a ridiculous pace these days. There is so much we don't know about immunology, but we are also learning so fast and biotech is accelerating too.
- gibba999 5y ago
  ... or using N95-equivalent masks and mild social distancing ... What's scary is gamma through omega.

rubyist5eva 5y ago

Already got it, recovered, don't give a s*it about this virus anymore. Give me my freedom back before I come and take it.

wombatmobile 5y ago

What is the nature of the delta mutations ie what mechanism/a make it more infectious?

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toss1 5y ago
The measured viral load is substantially higher (e.g., 1000x in some studies) vs the original strain, and it is suspected, but not proven (afaik) that this translates to more exhaled virus. What is known is that the virus ramps up in the infected people more quickly, and stays infectious longer, so for sure, each person is infectious for more days on both sides, increasing infectious opportunities. In the vaccinated population with breakthru Delta cases, the viral load initially approaches the load of unvaxed people in the first few days after becoming detectable, but then falls off much more rapidly.
- poisonarena 5y ago
  Can people who had the OG Covid(me) get it and get sick again? or are they more or less okay?
  - 6nf 5y ago
    There are only handful of verified cases of people getting covid more than once. It's extremely rare from what I can tell.
    - toss1 5y ago
      Both are fairly rare, but the latest data I've seen shows both 1) weaker and faster decaying immune response in previously infected people vs immune response from vaccine, and 2) previously infected people getting infected at abt 2X the rate of fully vaccinated people. (Sorry, no ref links on hand at the moment)

dcolkitt 5y ago

Here's my question. Current CFR for vaccinated individuals is under 0.05%. At that point does it matter if Covid's endemic? I think the problem is we're all anchored to Covid from early 2020, which was definitely a huge danger. So we hear that there's still community spread, and fly into a panic shutting everything down. But at 0.05% CFR, it's barely more dangerous than seasonal flu. If Covid in February 2020 had 0.05% would we even have done anything about it?

newsbinator 5y ago
Seasonal flu typically passes and has no lasting or permanent effects, in most cases. What % of people get Covid and are noticeably operating at less than 100% thereafter? What % are operating at less than 70% thereafter? Low CFR merely means you didn't die. It doesn't mean Covid didn't break you.
- dcolkitt 5y ago
  Long influenza absolutely does exist. At least to the same standard of self reported evidence that is being used to report long Covid. [1]https://time.com/5915616/long-flu-1918-pandemic/ https://time.com/5915616/long-flu-1918-pandemic/
- swiley 5y ago
  I've known multiple people that permanently lost their sense of taste after a bad flu.
throwawaysea 5y ago
COVID IFR was always low. The CDC planning scenarios (https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena...) consistently showed low IFR for those under 50 even mid 2020 in their earlier updates. However this was obfuscated by alarmist journalism and divisive politics, as well as people confusing CFR and IFR. COVID wasn’t that dangerous ever, unless you were immunocompromised or elderly, or unless your measure of danger is based on a high risk aversion. There is the possibility of rare lingering side effects. However studies show that the worst side effects, like ARDS, primarily affect those who are obese or vitamin D deficient. You could make an argument that it’s the individual’s’ responsibility to manage their own risks and vulnerability for that. Alternatively you could say that those comorbidities are common enough that they require society wide management.

anonymouswacker 5y ago

All of the anti-vaxxers were right this time around. What a complete clusterfuck.

midrus 5y ago
No, they're not. It would be a lot worse without the vaccines. Just compare how things are going on countries where vaccination is not happening vs countries that have a high population already vaccinated and you will see how ridiculous your comment is. Antivax and comments like this only makes things worse.
- dazag 5y ago
  Not listening to a*holes blindly accepting only one side of the narrative, at least open your eyes to the opposite, or you will never realize when you're right or wrong. It is just science man, it is call antithesis.
  - midrus 5y ago
    What part of more people dying because not having had the vaccine than people die from side effects of having had it? I suppose that's not science to you because it's not in a tweet.
- fidesomnes 5y ago
  It isn't a vaccine if you can still get covid and or spread it to others. It is an MRNA gene therapy with a covid viral load to boot immune system response by attaching itself to your DNA.

vimy 5y ago

Since the vaccines don’t seem to stop transmission their only use is to protect the ones who take it. So there is no need anymore for vaccine passports and forcing people to take it. Unless I’m missing something?

throwawaysea 5y ago
They don’t stop transmission but reduce its likelihood significantly. It seems someone who is vaccinated and very ill can be very infectious but generally vaccinated people are unlikely to infect others (reduced observed R0).
finolex1 5y ago
Vaccines definitely reduce transmission, just to a slightly smaller extent for the Delta variant. The CDC's messaging on this issue has been atrociously bad.
selcuka 5y ago
The vaccines don't stop transmission, but they still radically reduce it. Pfizer is 94% effective [1] in reducing transmissions of the original strain. Even with the delta variant it is still 64% effective: [1] https://www.businessinsider.com.au/israel-may-reimpose-coronavirus-restrictions-as-delta-variant-fuels-surge-2021-7 https://www.businessinsider.com.au/israel-may-reimpose-coron...
shock-value 5y ago
The do vastly lower the rate of transmission. That could translate into lower peak hospital utilization (even not accounting for their ability to prevent illness) which is good for everyone. I do agree that this thing is going to spread in an unbounded manner regardless of what we do now though.
kyrra 5y ago
Total guess: Slows down transmission. Those that are asymptomatic should have a lower viral load, which results in fewer cases.
MereInterest 5y ago

farmerstan 5y ago

This doesn’t make sense. People who are infected by delta variant will become immune to delta variant. So if they are infected and it runs it’s course through the human population, people will get herd immunity from it. Or if we create a vaccine for delta variant similar thing should happen. But we also already know that we don’t achieve sterilizing immunity from coronavirus even with previous infection or vaccine. So it was never the case that we couldn’t stop transmitting the disease.

nevir 5y ago
I don't believe it's actually the case that once you are infected by the delta strain your body has lasting immunity to that same strain. It looks like that also is affected by age and other constraints: https://www.nature.com/articles/d41586-020-00502-w https://www.nature.com/articles/d41586-020-00502-w
- base698 5y ago
  The vaccine is a single antigen. A live virus has many antigens. It makes sense your body would have more attacks if naturally infected.
- farmerstan 5y ago
  To not have lasting immunity to the same strain is anti-science. We already know that people who were previously infected by covid are immune to many different variants. To think otherwise would be illogical. Even SARS patients from 2003 have immunity to SARS 18 years later.
paulmd 5y ago
> People who are infected by delta variant will become immune to delta variant "people who were exposed to H1N1 flu last year will become immune to it, so once it runs its course people will get herd immunity from it and the virus will die out". that's not how it works. What the scientist is saying here is that it's mutating fast enough that by the time we start to approach "herd immunity" (via vaccination or just exposure) it's mutated and the herd immunity is no longer effective against the new variant. So yeah you're immune to the strain from last year, but it doesn't do anything against this year's strain. and on top of that Delta is literally so infectious that it'll just about spread right through the existing vaccines. The vaccines were 98% effective against the initial strain, now Pfizer/Moderna are 88% effective, which means you have 6x as much spread (at an epi/population level), on top of a strain that is, itself, 2.5x as transmissible. So now we have to hit a much higher level of vaccination (near-100%) to get the reproduction number under 1.0. And then you've got the other vaccines - some early studies indicated Astra-Zeneca is only about 60% effective (!) which means even with 100% vaccination that vaccine could not stop the spread. Best-case scenario you have to get those people a booster shot of something else - and the clock is still ticking, it is still mutating and in another year the effectiveness of all the existing vaccines will be even lower. And on top of that, those are only the "severe illness" numbers, the "mild/moderate" illness numbers are higher, vaccinated people still spread an appreciable amount, and it's spreading through kids very aggressively now (funny how HN told me just last week that kids were immune and we could reopen schools...) In short if you want vaccines to actually work and reach herd immunity - you have to slow it down enough with containment measures to slow down the rate of mutation. Because if you just let people get exposed, every exposed person is another chance for the virus to mutate, and it's mutating fast enough that by the time we get everyone vaccinated, the virus will have mutated enough the vaccines are no longer very effective. (And reality check - we've barely got a start on vaccinating the global population, which is what you really have to do to control it. Vaccines are flowing like water in the US and Europe, and to a lesser extent in other developed nations, but in a lot of the world you just can't get a fucking vaccine even if you want one. A few months ago the number was something like 140 countries hadn't even gotten a single dose of vaccine yet.) Realistically that is no longer possible at this point. People are done with quarantine and social distancing and 40% of the country won't get vaccinated even when they're free and readily available. And now it's mutated to become several times as transmissible - that's game over. It's over, it's going to become endemic, it's a foregone conclusion at this point.

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johnp314 5y ago

Has anyone looked at the Johns Hopkins COVID map and considered Sweden? Last year they were the country all the lockdown experts vilified (and libertarians envied). Today, Aug 12 2021, among most all western nations they show essentially no delta-bump. How do all you experts blaming anti-vaxers and AstraZeneca scientists looking at Israel explain this data point? What has given Sweden this apparent immunity from delta? It's annoying when inconvenient reality gets in the way of our theoretical science.

glangdale 5y ago
They had a ton of COVID cases (1M, in a population of 10M!) and have vaccinated heavily. They're also doing a lot of the social distancing things that they initially avoided. Vaccination does reduce the chance of spreading the virus. Having 10% of the country get the natural variant and 45% fully immune, plus still doing the social distancing stuff, and requiring negative COVID tests for those entering the country, seems like a pretty good way of keeping delta under control.
- nradov 5y ago
  As in every other country the case count is way lower than the actual number of infections. Most infected people never get tested or officially counted. They estimate that about 33% of Swedes had been infected by May 2021 and presumably the number is higher now. https://www.news-medical.net/news/20210714/e2809cHerd-immunitye2809d-not-responsible-for-Swedene28099s-control-of-COVID-19-say-researchers.aspx https://www.news-medical.net/news/20210714/e2809cHerd-immuni... As a comparison point the CDC estimates that about 36% of Americans have been infected. https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burd...
  - glangdale 5y ago
    Yeah, that would be even more consistent with the idea that there's a combination of natural resistance (if not immunity) from the first form of the virus (I think you can get again) as well as resistance for vaccination. It's not going to be 33% + 45% because there'd be overlap in the categories, but that's probably a pretty high rate of resistance. Couple that with the fact that the Swedes aren't acting completely stupid and are doing a pretty good job of voluntary distancing (not to mention border control) and it seems like the numbers are pretty easily explained. Quite the cost to get there...

glangdale 5y ago

As far as I can tell the conclusions we're going to have to draw are: 1) We need to keep using all strategies - including masking, social distancing, and targeted lockdowns - to reduce large scale spread of the virus. If we don't, we're going to be playing "new variant whack-a-mole" until the end of time. 2) Vaccination is critical to make the above task easier but it's not enough it itself. There seems to be a lot of evidence that it reduces chance of passing it on and the severity of the cases, but it's clearly not enough by itself (see Israel, although the remaining unvaccinated population is a big factor anywhere in passing COVID on). We're also going to have to start kicking the asses of the pointlessly vaccine-skeptical through harsh restrictions and denial of things. In Australia, once we have universal access to the vaccine, I would be quite keen to see vaccine refusers not treated for free if they do get COVID - I'd support a "HECS"-like scheme for people who get avoidable diseases like this, including the government getting to sell your house when you die to recoup costs. 3) There's a pile of stuff we don't know about the long-term effects of COVID-19 and some ominous indications that it's Really Not Good. I don't want to get into a case-by-case with a bunch of self-appointed Internet Experts about this but there's a lot of medical opinion out there that long COVID is real and serious (particularly on the neurological side). We don't know how bad it really is because no-one has had COVID for more than 2 years. Having participated in the care of multiple relatives over the years with dementia, one thing that chills me is the prospect that COVID will lead to even a slight uptick in the chance of getting Lewy body dementia or Parkinson's. That's a fucking public health tsunami. We also don't know much about the effects of lockdown, etc. but the picture seems to be complex and indecisive. All the anti-lockdown people going on about suicides and depression apparently think the only source of suicide and depression in a massive pandemic where people are losing folks dear to them and are terrified of getting a debilitating disease is because they are locked down. As usual, it's the typical overreach of the Internet Expert. Normal is a very long way off. The implications of COVID being 'endemic' certainly aren't what most people casually tossing the word around think they are, and magical thinking about 'living with the virus' isn't going to make long COVID go away.

nradov 5y ago
It's too late to prevent large-scale spread of the virus. That already happened and it's now endemic worldwide. We don't have a time machine. You obviously can't expect most people to continue tolerating masking, social distancing, and lockdowns indefinitely with no clear, achievable exit criteria. That would be absurd and people in free societies won't comply regardless of the potential consequences. You can complain that they're being irresponsible and putting others at risk but that won't change the reality. At some point we'll have to accept the risk and move forward with normal life. Fortunately the vaccines are very effective at preventing deaths.

rich_sasha 5y ago

I wonder how Covid compares to the bubonic plague. It remains endemic in some parts of Asia (so not disappeared), it is zoonotic (rodents, even cute squirrels in some parts of the US), killed off something like 1/3rd of Europe’s population, and... is generally a non-event nowadays. Not a pretty comparison if valid, of course. But that was what would be a nightmare scenario for Covid: letting the disease rip through a populous continent. And yet it burnt out eventually, over the course of 7 years, according to Wikipedia. For the most part, anyway. Bubonic plague outbreaks continued for centuries, but never again was there a continent-wide pandemic.

hellisothers 5y ago
Isn’t that partially because some people had better resistance to it and the survivors passed it on? https://www.studyfinds.org/bubonic-plague-human-immunity/ https://www.studyfinds.org/bubonic-plague-human-immunity/
- rich_sasha 5y ago
  Maybe. This could happen with Covid too. Not a pretty scenario! But better than deadly-remains-forever.
candiodari 5y ago
Is this a trap question? I mean you can make 2 cases. Firstly the noncontroversial part: covid is a virus, bubonic plague is a bacterium. In the covid case, infected people infect others. Stay away from people, especially in restaurants (so, probably, eating near an infected person is a strong vector), and there isn't much chance of infection. In the case of bubonic plague: enter a building where an infected person had a shit 2 months before ... there's a decent chance you get infected. It's a world of difference. Objects are safe, with covid. Streets are safe. Beds are safe. Public toilets are safe. Public toilets would be a death trap with the bubonic plague. You ignore age? They're comparable in death rate. You only count people under 40 (life expectancy, without bubonic plague, was only about 30-40 years when bubonic plague got it's big moment). So if you compare that to what covid does to people <40, it's much less than the mildest flu ... Let's say you relax that by a lot and say, no people live to 70 in the 14th century, about double the real figure ... covid is about an average flu. So ... like everything, it depends. If you make a case based on years lost, covid is an exceptionally deadly flu, but less than 1% as bad as the bubonic plague. If you make a better comparison, and compare Covid to Tuberculosis, today, then for the first 4 months it got to about half as bad as TBC, then fell off a cliff. If you take an average over a year, TBC wins on all fronts: people infected, people killed, years of life destroyed, ... well, except on dollars spent. BUT covid kills many rich old people in the west. Tuberculosis kills young poor adults, mostly in the third world. Tuberculosis produces orphans. Not that I don't think rich people in the west they have right to a few more years, they very much do. But you want to help humanity, it's the wrong target. So Covid only really wins from even contemporary diseases in the "dollars resisting the deaths" department.

loftyal 5y ago

Wont we achieve herd immunity via natural infecion then? Unless the virus starts to become like flu, which evades the the natural immunty very easily.

bananapub 5y ago
if the problem is that the immune response drops too low to prevent infection then there may be no herd immunity from that either, it can just cycle around.
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nradov 5y ago
With highly contagious diseases, herd immunity is kind of a meaningless concept. Eventually close to 100% of people get infected.

bartimus 5y ago

It seems they are confusing herd immunity with complete eradication? Most likely the virus will become endemic. We've already achieved a level of herd immunity.