25 ms·

Covid deaths plunge after 75% of town's adults vaccinated

172 points by astdb 5y ago

beervirus 5y ago
> mass vaccination with the Chinese-developed CoronaVac The drop in death rate is probably just a coincidence then.
meepmorp 5y ago
Is this surprising? That’s right in line with the expected herd immunity threshold for the sars-cov2. Epidemiology works.
- version_five 5y ago
  That's the first thing I thought when I saw this (hopefully your detractors will explain themselves). It seems almost tautological. If you've accepted that the vaccine is effective, then it's effective when it gets used at scale.
  - whatshisface 5y ago
    You're going down a dangerous road with that "seems almost tautological" perspective, because it is only one step away from "it's tautological, why bother checking?"
    - version_five 5y ago
      Interesting, and I agree. The opposite result, mass vaccination and no change in outcome would have been important news, because it's new and unexpected information. But news that a vaccine that is shown to work works is a much less interesting outcome.
    - monkellipse 5y ago
      Yes. Sometimes science seems silly for confirming things we think we already know. But if we don’t confirm them scientifically (especially when the stakes are high) we aren’t much better off than the magically-minded folk… Also, vaccine effectiveness in the real world is an important area of study, surely it’s good to know with higher certainty that the vaccine is effective against today’s disease, no?
    - lmilcin 5y ago
      It is not tautological. Vaccines are designed and created based on enormous body of knowledge gathered over the past century. We know it works for sure because of trust in all that knowledge. We know what viruses are, how they work in principle. We can use that knowledge to predict what is going to happen if we disrupt how they multiply or spread or gain access to our cells. That knowledge is not self evident -- it has been hard won by generations of scientists.
      - whatshisface 5y ago
        >We know what viruses are, how they work in principle. We can use that knowledge to predict what is going to happen if we disrupt how they multiply or spread or gain access to our cells. I think that's a misapprehension of how drug development works in practice. The models can lead towards discoveries, but most drugs fall out of the pipeline due to being unexpectedly unsafe or ineffective. The "checking if it actually works" step is the most important part of medicine by a large margin.
        lmilcin 5y ago
        What I meant is we know what happens if we have working vaccine. Meaning that working vaccine leads to less people being sick and that leads to less deaths from virus. As to the vaccine itself it is usually easy to come up with a formula that can disrupt the virus (any potent poison or lava flow can do that). The difficult part is that the formula must also not disrupt anything important. No amount of knowledge about virology can help with the second part, human body is vastly more complex than the virus.
      - version_five 5y ago
        I should have been clearer. I meant that if it was shown to be effective in clinical trials, then it's unsurprising that it worked when deployed in practice.
        whatshisface 5y ago
        The strains in the wild at the time of the clinical trials are different from the strains in the wild now. Furthermore, the trials did not test herd immunity, only direct immunity.
- refurb 5y ago
  No one knows the herd immunity threshold for these vaccines. Based on cases of vaccinated people getting Covid infections, this is just the vaccine preventing serious infections.
  - standardUser 5y ago
    Vaccines prevent infections in the vast majority of cases, not just severe infections. Not why this misinformation keeps being spread around. https://www.cdc.gov/media/releases/2021/p0329-COVID-19-Vaccines.html https://www.cdc.gov/media/releases/2021/p0329-COVID-19-Vacci...
    - refurb 5y ago
      Your link doesn't contradict anything I said so I'm not sure why you are claiming it's "misinformation". A 90% reduction of infection means vaccinated individuals still get infected. That's what other countries have seen as seen.[1] 300 unvaccinated COVID-19 cases in current Singapore outbreak vs 78 vaccinated If vaccinated people still get infected (even asymptomatically or at a lower rate) then they can transmit to the unvaccinated. There is no sterilizing immunity therefore the herd immunity threshold is likely much higher than 75%. Basically if you aren't vaccinated, you aren't protected. [1]https://www.channelnewsasia.com/news/singapore/covid-19-vaccination-effectiveness-moh-ong-ye-kung-14869342 https://www.channelnewsasia.com/news/singapore/covid-19-vacc...
- lmilcin 5y ago
  The anti-vaccine movement is not going to stop because these people are not persuaded by facts or arguments. Yes, we know epidemiology works. No, this proves nothing to people who do not listen.
  - deleted 5y ago
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  - tobesure 5y ago
    It's dishonest to conflate people who are hesitant about covid vaccines with anti-vaxxers. No amount of "listening" will change the fact that all three vaccines are untested (it will take time for manifestation and detection of possible long term side effects), and the two primary vaccines are novel technologies. The truth of the matter is that covid vaccination has its risks and they need to be weighed against those of the virus. And when you make an honest effort to perform such an evaluation, the choice is not quite so clear cut.
    - bawolff 5y ago
      > No amount of "listening" will change the fact that all three vaccines are untested They've had significant testing, similar to other medications of a similar type. Do you have an actual threshold you think would be a reasonable amount of "testing" and a reasonable argument as to why that is an appropriate amount as oposed to just picked at random? Or is this the sort of thing where someone could run a 100 year study, and you would still object, because what-if i live to a ripe ole' 150 and the long term effects only start 110 years later?
      - totony 5y ago
        Not parent, but I think it's pretty clear (at least) mRNA vaccines have not had "[testing] similar to other medications of a similar type," because they are quite novel and the first of their kind that has been approved for widespread use. (Aka they had testing, but not as strong historical real-world testing as others) As for the other available vaccines, I'm not as familiar, but they seem more tested (although less efficient afaik). Although they also have their risks, especially for younger people, which one may want to factor in their risk/cost analysis.
- beervirus 5y ago
  Moderna works. Pfizer works. JJ works. Chinese vaccines though…
  - deleted 5y ago
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  - mchusma 5y ago
    Works? This study showed a Chinese vaccine worked.
    - deleted 5y ago
      [deleted]
  - bsder 5y ago
    Except the first vaccines mentioned require functional cold chains, which a country like Brazil does not have. While things like the Gamelaya vaccine deserved the slagging it got, that in no way makes me any happier. We need vaccines like the ones from China and Russia that don't require negative stupid Celsius to store and distribute so we can get everybody on this planet vaccinated.
    - cromwellian 5y ago
      That's all well and good, but Seychelles is the most vaccinated country on earth, got the Chinese vaccine, and had another COVID surge, leading to a Chinese authority advising them to give everyone a THIRD DOSE of the vaccine. https://www.bbc.com/news/world-africa-56992121 https://www.bbc.com/news/world-africa-56992121
      - deleted 5y ago
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      - bsder 5y ago
        That's ... unfortunate. I was really hoping that someone was going to have a useful inactivated virus vaccine as storing and transporting those is much easier. It looks like J&J is going to have the field to itself for a single dose, reasonable storage vaccine.
- paxys 5y ago
  We know it works only because there are scientific studies confirming it. If we stop doing the studies just because the results are "obvious" by now, we won't know if/when something changes and our assumptions don't hold anymore. Not every new study has to be a surprise. Ones that confirm the status quo are equally valuable.
  - Dylan16807 5y ago
    Okay? Nobody suggested the study wasn't worth doing. But reporting on the non-surprising result as if it's surprising is weird.
    - ycombigator 5y ago
      The BBC is a state broadcaster, not just a news agency. It has social goals.
      - h0l0cube 5y ago
        What are ulterior motives you see here?
        nexuist 5y ago
        Increasing vaccination rates? It shows that the potential benefits outweigh the potential risks.
- bawolff 5y ago
  My understanding is that the estimated range for herd immunity was quite a large range, from 60-90%. I suppose 75 is right in the middle of that, but given the big range, getting more data seemed prudent. Edit: i missed that we're talking about CoronaVac, where the range i cited was for a different vaccine.
  - totony 5y ago
    75% seemed to be from immune people (from that nature article that showcased the maths). It's curious to me a 50%(correct me if I'm wrong) efficiency vaccine would work at 75%. I guess they had some natural immunity already? EDIT: Nevermind, it would work anyway because the vaccines prevent more dangerous effects. So if you vaccinate at-risk people, ofc your deaths would lower
    - h0l0cube 5y ago
      > It's curious to me a 50%(correct me if I'm wrong) efficiency vaccine From the article that's the lowest estimate: > The results of the experiment could give a boost to the CoronaVac, which is being used by dozens of developing countries. There was some controversy about the vaccine this year, after clinical trials in Brazil, Indonesia and Turkey put its efficacy in a range of 50% to 90%.
    - bawolff 5y ago
      75% of population getting a vaccine with 50% efficacy could induce heard immunity, it depends what the reproduction rate is. Covid has a fairly high reproduction rate so it seems unlikely (although the 50% number might be incorrect), but as a general principle its possible for 75% of pop with 50% efficacy to trigger heard immunity if the viruses reproduction rate was low enough.
      - mjevans 5y ago
        Mixed with other efforts, E.G. masking and social distancing, create sufficient reduction to make previously stalling campaigns sufficiently effective. Maybe enough to strangle the disease out if those other measures are held long enough.
- smnrchrds 5y ago
  > Is this surprising? To an extent. Just a couple of weeks ago, this was in the news: "Why the world’s most vaccinated country is seeing an unprecedented spike in coronavirus cases" [0] [0] https://www.washingtonpost.com/world/2021/05/06/seychelles-vaccines-covid-cases/ https://www.washingtonpost.com/world/2021/05/06/seychelles-v...
  - adventured 5y ago
    Britain - which is of course highly vaccinated - is seeing recent small (so far) problems with spikes as well [1], due to the Delta (India B.1.617.2) variant now spreading there. There doesn't seem to be much consensus as to what a high-vaccination (and, in theory, high herd immunity) location like Britain might expect against that variant. The US will find out pretty soon how the mRNA vaccines hold up against it, as I imagine it'll blanket the US in the coming months. [1] https://www.theguardian.com/world/2021/may/31/scientists-call-uk-speed-up-second-covid-jabs-india-variant-spreads https://www.theguardian.com/world/2021/may/31/scientists-cal...
- ufo 5y ago
  It's not surprising, but it's very good to see an experiment confirming that prediction.
- apatheticonion 5y ago
  > Epidemiology works. Not according to my colleagues who, to my frustration, believe podcasts are more credible than scientific literature. Which surprised me. They are intelligent people, how does that happen?
asperous 5y ago
There is actually more interesting things going on here then the title suggests. They split this small city into 4 and offered each section vaccines at a different time to get a better real-world test of the exact herd immunity point. https://clinicaltrials.gov/ct2/show/NCT04747821 https://clinicaltrials.gov/ct2/show/NCT04747821 https://www.sciencenews.org/article/coronavirus-pandemic-serrana-brazil-covid-mass-vaccine https://www.sciencenews.org/article/coronavirus-pandemic-ser...
williesleg 5y ago
You mean masks didn't work?
ArkanExplorer 5y ago
COVID deaths are plunging across the northern hemisphere, because of seasonality effects. For example Ukraine has vaccinated only 2.3% of its population with at least one dose, but COVID cases are down 81% from peak and are continuing to decline.
- whatever_dude 5y ago
  This study was conducted in the Southern Hemisphere.
- shard 5y ago
  There didn't seem to be any seasonality effects last year during this time. What's different this year?
woliveirajr 5y ago
> Serrana, with 45,000 inhabitants 20 deaths in March/2021 to 6 in April/2021. When you go to see the stats since April/2020, you'll notice that there were full months with 0 or 1 death. [0] Too soon, too small sample to draw such conclusions. [0] For ex., search for "Serrana" in this site: https://especiais.gazetadopovo.com.br/coronavirus/casos-no-brasil-por-cidades/ https://especiais.gazetadopovo.com.br/coronavirus/casos-no-b... edit: typo, should be "april/2020"
- deleted 5y ago
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- seanmcdirmid 5y ago
  The end of winter probably has a lot to do with it also (just like flu deaths go down during the spring and summer). The vaccines effectiveness probably won’t show through very visibly until November.
  - brlewis 5y ago
    With Brazil being on the equator and mostly south of it, I doubt the end of northern hemisphere winter has much to do with it.
    - cesarb 5y ago
      > With Brazil being on the equator and mostly south of it Brazil is a huge country. The city in question is a long way south of the equator, it's near the tropic of Capricorn.
      - renatovico 5y ago
        It’s start of Winter here, i live 100km from serrana
    - thu2111 5y ago
      Seasonality isn't really understood at all by epidemiologists, so it's probably best to confine discussion of it to the places where it's clearly visible, which is mostly the northern hemisphere indeed.
void_mint 5y ago
I am _shocked_.
godmode2019 5y ago
This is a Chinese vaccine, probably looking for good western PR. Since the dates where omitted one can safely assume they timed the 2nd jab with the end if a flu season. A quick google shows this is March - April. Covid deaths spike during the flu season. They should realistically compare to average deaths for that time period, rather than comparing flu season deaths to non flu season deaths.
- bellyfullofbac 5y ago
  Ok Mr. Expert "It's just a flu". Except this is Brazil, which is the southern hemisphere, where flu season is May to October. Quick, find another alternative explanation!
  - godmode2019 5y ago
    Maybe you should double check your information before you post. It makes you look like a complete worthless fool. The flu season is a weather event, 'covid' kills more people during this weather event. This weather event just finished in Brazil, its tropical so its more similar to India than Australia.
- chapium 5y ago
  By publishing scientific research. How dare they.
- redis_mlc 5y ago
  The parent has a point. If the CCP is involved, they can't report anything negative without retaliation.
- shard 5y ago
  Is the flu much of a problem this year? I thought the flu infection rate was way down due to social distancing and lockdowns. The comparison you are suggesting might not be an accurate one.
  - godmode2019 5y ago
mxcrossr 5y ago
This seems like good news for a country like Bahrain. It’s unfortunate that the Chinese vaccine isn’t as effective as the competition (such that the current ~50% deployment isn’t enough), but getting to 75% is a realistic goal still.
- ec109685 5y ago
  The vaccine reduced deaths by 95%. It seems pretty effective.
zoom6628 5y ago
Let's hope to see more studies like this. Here in Hong Kong there is a prevailing public view of the vaccines being too new and created too quickly esp the mRNA ones. Public don't understand that mRNA was decades in the making and is engineered which is why available so quickly. The cultivated traditional vaccines took a little longer due to process. But maybe now people will understand the importance of herd immunity because until that is achieved world wide then this pandemic will stay with us. I worry it will be like tuberculosis and hang around amongst the poor and dense populations, further reducing their chances for good quality of life in places with large populations,high density, and prevailing poverty.
AuthorizedCust 5y ago
While I strongly believe in vaccines, I note that the Dallas, Texas (USA) area has seen similar improvements, and we’re hardly a high-vaccination area. Vaccines surely help, but there seems to be an additional force beyond 1. vaccination rates and 2. natural immunity that could be inferred based on data-informed infection rates. Almost every pandemic measure has been eliminated in Texas the past two months, and the fatality, positivity, and hospitalization rates have kept going down. (The state has prevented local jurisdictions from extending measures.) My guess is that asymptomatic infection rates may have been far higher than what the professionals believe or herd immunity happens at considerably lower levels than believed. I don’t know how else to explain this. For backup, here’s various plots I’m making from official state data. The hospitalizations are probably the most reliable metric, and like the other metrics, they are just falling off a cliff. https://www.arencambre.com/covid-19-stats-for-dallas-and-texas/ https://www.arencambre.com/covid-19-stats-for-dallas-and-tex...
- ceph_ 5y ago
  You really trying to say it isn't the vaccine. When vaccine availability is the only positive thing that changed?
  - kapp_in_life 5y ago
    We're also entering the summer months which I hazily remember somehow negatively impacting Covid-19's ability to spread last year.
    - igetspam 5y ago
      I challenge your hazy memory with a "false." Late spring was when we started seeing infections. Summer being hot was what we were told would help. The data showed otherwise. As you've provided none of your own, I'll go ahead and do the same.
      - Izkata 5y ago
        There's a few states where the drop in the summer was really obvious, like Illinois and New York, and others that didn't spike until the fall, like Washington and Montana. Cases being low in the summer is common in the northern states, which is probably what GP is hazily remembering.
akamaka 5y ago
The article doesn’t mention how much natural immunity exists in the community, which is presumably high given the large outbreaks in Brazil. Is there a study which has calculated a more precise herd immunity threshold, taking this effect into account?
pengaru 5y ago
In 2021 are we supposed to be surprised to learn vaccines actually work?
kenneth 5y ago
Pretty impressive result for a vaccine that's been shown to barely have the 50% efficacy threshold to make the cut (and with doubts about its results due to no releasing of trial data). Shows high promise for countries using mRNA vaccines.
Markoff 5y ago
I could make same headline about Czechia - COVID deaths plunge after less than 40% adults vaccinated and warm weather came from 200+ deaths per day we are at <20 deaths

172 points by astdb 5y ago

> mass vaccination with the Chinese-developed CoronaVac The drop in death rate is probably just a coincidence then.

Is this surprising? That’s right in line with the expected herd immunity threshold for the sars-cov2. Epidemiology works.

version_five 5y ago
That's the first thing I thought when I saw this (hopefully your detractors will explain themselves). It seems almost tautological. If you've accepted that the vaccine is effective, then it's effective when it gets used at scale.
- whatshisface 5y ago
  You're going down a dangerous road with that "seems almost tautological" perspective, because it is only one step away from "it's tautological, why bother checking?"
  - version_five 5y ago
    Interesting, and I agree. The opposite result, mass vaccination and no change in outcome would have been important news, because it's new and unexpected information. But news that a vaccine that is shown to work works is a much less interesting outcome.
  - monkellipse 5y ago
    Yes. Sometimes science seems silly for confirming things we think we already know. But if we don’t confirm them scientifically (especially when the stakes are high) we aren’t much better off than the magically-minded folk… Also, vaccine effectiveness in the real world is an important area of study, surely it’s good to know with higher certainty that the vaccine is effective against today’s disease, no?
  - lmilcin 5y ago
    It is not tautological. Vaccines are designed and created based on enormous body of knowledge gathered over the past century. We know it works for sure because of trust in all that knowledge. We know what viruses are, how they work in principle. We can use that knowledge to predict what is going to happen if we disrupt how they multiply or spread or gain access to our cells. That knowledge is not self evident -- it has been hard won by generations of scientists.
    - whatshisface 5y ago
      >We know what viruses are, how they work in principle. We can use that knowledge to predict what is going to happen if we disrupt how they multiply or spread or gain access to our cells. I think that's a misapprehension of how drug development works in practice. The models can lead towards discoveries, but most drugs fall out of the pipeline due to being unexpectedly unsafe or ineffective. The "checking if it actually works" step is the most important part of medicine by a large margin.
      - lmilcin 5y ago
        What I meant is we know what happens if we have working vaccine. Meaning that working vaccine leads to less people being sick and that leads to less deaths from virus. As to the vaccine itself it is usually easy to come up with a formula that can disrupt the virus (any potent poison or lava flow can do that). The difficult part is that the formula must also not disrupt anything important. No amount of knowledge about virology can help with the second part, human body is vastly more complex than the virus.
    - version_five 5y ago
      I should have been clearer. I meant that if it was shown to be effective in clinical trials, then it's unsurprising that it worked when deployed in practice.
      - whatshisface 5y ago
        The strains in the wild at the time of the clinical trials are different from the strains in the wild now. Furthermore, the trials did not test herd immunity, only direct immunity.
refurb 5y ago
No one knows the herd immunity threshold for these vaccines. Based on cases of vaccinated people getting Covid infections, this is just the vaccine preventing serious infections.
- standardUser 5y ago
  Vaccines prevent infections in the vast majority of cases, not just severe infections. Not why this misinformation keeps being spread around. https://www.cdc.gov/media/releases/2021/p0329-COVID-19-Vaccines.html https://www.cdc.gov/media/releases/2021/p0329-COVID-19-Vacci...
  - refurb 5y ago
    Your link doesn't contradict anything I said so I'm not sure why you are claiming it's "misinformation". A 90% reduction of infection means vaccinated individuals still get infected. That's what other countries have seen as seen.[1] 300 unvaccinated COVID-19 cases in current Singapore outbreak vs 78 vaccinated If vaccinated people still get infected (even asymptomatically or at a lower rate) then they can transmit to the unvaccinated. There is no sterilizing immunity therefore the herd immunity threshold is likely much higher than 75%. Basically if you aren't vaccinated, you aren't protected. [1]https://www.channelnewsasia.com/news/singapore/covid-19-vaccination-effectiveness-moh-ong-ye-kung-14869342 https://www.channelnewsasia.com/news/singapore/covid-19-vacc...
lmilcin 5y ago
The anti-vaccine movement is not going to stop because these people are not persuaded by facts or arguments. Yes, we know epidemiology works. No, this proves nothing to people who do not listen.
- deleted 5y ago
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- tobesure 5y ago
  It's dishonest to conflate people who are hesitant about covid vaccines with anti-vaxxers. No amount of "listening" will change the fact that all three vaccines are untested (it will take time for manifestation and detection of possible long term side effects), and the two primary vaccines are novel technologies. The truth of the matter is that covid vaccination has its risks and they need to be weighed against those of the virus. And when you make an honest effort to perform such an evaluation, the choice is not quite so clear cut.
  - bawolff 5y ago
    > No amount of "listening" will change the fact that all three vaccines are untested They've had significant testing, similar to other medications of a similar type. Do you have an actual threshold you think would be a reasonable amount of "testing" and a reasonable argument as to why that is an appropriate amount as oposed to just picked at random? Or is this the sort of thing where someone could run a 100 year study, and you would still object, because what-if i live to a ripe ole' 150 and the long term effects only start 110 years later?
    - totony 5y ago
      Not parent, but I think it's pretty clear (at least) mRNA vaccines have not had "[testing] similar to other medications of a similar type," because they are quite novel and the first of their kind that has been approved for widespread use. (Aka they had testing, but not as strong historical real-world testing as others) As for the other available vaccines, I'm not as familiar, but they seem more tested (although less efficient afaik). Although they also have their risks, especially for younger people, which one may want to factor in their risk/cost analysis.
beervirus 5y ago
Moderna works. Pfizer works. JJ works. Chinese vaccines though…
- deleted 5y ago
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- mchusma 5y ago
  Works? This study showed a Chinese vaccine worked.
  - deleted 5y ago
    [deleted]
- bsder 5y ago
  Except the first vaccines mentioned require functional cold chains, which a country like Brazil does not have. While things like the Gamelaya vaccine deserved the slagging it got, that in no way makes me any happier. We need vaccines like the ones from China and Russia that don't require negative stupid Celsius to store and distribute so we can get everybody on this planet vaccinated.
  - cromwellian 5y ago
    That's all well and good, but Seychelles is the most vaccinated country on earth, got the Chinese vaccine, and had another COVID surge, leading to a Chinese authority advising them to give everyone a THIRD DOSE of the vaccine. https://www.bbc.com/news/world-africa-56992121 https://www.bbc.com/news/world-africa-56992121
    - deleted 5y ago
      [deleted]
    - bsder 5y ago
      That's ... unfortunate. I was really hoping that someone was going to have a useful inactivated virus vaccine as storing and transporting those is much easier. It looks like J&J is going to have the field to itself for a single dose, reasonable storage vaccine.
paxys 5y ago
We know it works only because there are scientific studies confirming it. If we stop doing the studies just because the results are "obvious" by now, we won't know if/when something changes and our assumptions don't hold anymore. Not every new study has to be a surprise. Ones that confirm the status quo are equally valuable.
- Dylan16807 5y ago
  Okay? Nobody suggested the study wasn't worth doing. But reporting on the non-surprising result as if it's surprising is weird.
  - ycombigator 5y ago
    The BBC is a state broadcaster, not just a news agency. It has social goals.
    - h0l0cube 5y ago
      What are ulterior motives you see here?
      - nexuist 5y ago
        Increasing vaccination rates? It shows that the potential benefits outweigh the potential risks.
bawolff 5y ago
My understanding is that the estimated range for herd immunity was quite a large range, from 60-90%. I suppose 75 is right in the middle of that, but given the big range, getting more data seemed prudent. Edit: i missed that we're talking about CoronaVac, where the range i cited was for a different vaccine.
- totony 5y ago
  75% seemed to be from immune people (from that nature article that showcased the maths). It's curious to me a 50%(correct me if I'm wrong) efficiency vaccine would work at 75%. I guess they had some natural immunity already? EDIT: Nevermind, it would work anyway because the vaccines prevent more dangerous effects. So if you vaccinate at-risk people, ofc your deaths would lower
  - h0l0cube 5y ago
    > It's curious to me a 50%(correct me if I'm wrong) efficiency vaccine From the article that's the lowest estimate: > The results of the experiment could give a boost to the CoronaVac, which is being used by dozens of developing countries. There was some controversy about the vaccine this year, after clinical trials in Brazil, Indonesia and Turkey put its efficacy in a range of 50% to 90%.
  - bawolff 5y ago
    75% of population getting a vaccine with 50% efficacy could induce heard immunity, it depends what the reproduction rate is. Covid has a fairly high reproduction rate so it seems unlikely (although the 50% number might be incorrect), but as a general principle its possible for 75% of pop with 50% efficacy to trigger heard immunity if the viruses reproduction rate was low enough.
    - mjevans 5y ago
      Mixed with other efforts, E.G. masking and social distancing, create sufficient reduction to make previously stalling campaigns sufficiently effective. Maybe enough to strangle the disease out if those other measures are held long enough.
smnrchrds 5y ago
> Is this surprising? To an extent. Just a couple of weeks ago, this was in the news: "Why the world’s most vaccinated country is seeing an unprecedented spike in coronavirus cases" [0] [0] https://www.washingtonpost.com/world/2021/05/06/seychelles-vaccines-covid-cases/ https://www.washingtonpost.com/world/2021/05/06/seychelles-v...
- adventured 5y ago
  Britain - which is of course highly vaccinated - is seeing recent small (so far) problems with spikes as well [1], due to the Delta (India B.1.617.2) variant now spreading there. There doesn't seem to be much consensus as to what a high-vaccination (and, in theory, high herd immunity) location like Britain might expect against that variant. The US will find out pretty soon how the mRNA vaccines hold up against it, as I imagine it'll blanket the US in the coming months. [1] https://www.theguardian.com/world/2021/may/31/scientists-call-uk-speed-up-second-covid-jabs-india-variant-spreads https://www.theguardian.com/world/2021/may/31/scientists-cal...
ufo 5y ago
It's not surprising, but it's very good to see an experiment confirming that prediction.
apatheticonion 5y ago
> Epidemiology works. Not according to my colleagues who, to my frustration, believe podcasts are more credible than scientific literature. Which surprised me. They are intelligent people, how does that happen?

asperous 5y ago

There is actually more interesting things going on here then the title suggests. They split this small city into 4 and offered each section vaccines at a different time to get a better real-world test of the exact herd immunity point. https://clinicaltrials.gov/ct2/show/NCT04747821 https://clinicaltrials.gov/ct2/show/NCT04747821 https://www.sciencenews.org/article/coronavirus-pandemic-serrana-brazil-covid-mass-vaccine https://www.sciencenews.org/article/coronavirus-pandemic-ser...

williesleg 5y ago

You mean masks didn't work?

ArkanExplorer 5y ago

COVID deaths are plunging across the northern hemisphere, because of seasonality effects. For example Ukraine has vaccinated only 2.3% of its population with at least one dose, but COVID cases are down 81% from peak and are continuing to decline.

whatever_dude 5y ago
This study was conducted in the Southern Hemisphere.
shard 5y ago
There didn't seem to be any seasonality effects last year during this time. What's different this year?

woliveirajr 5y ago

> Serrana, with 45,000 inhabitants 20 deaths in March/2021 to 6 in April/2021. When you go to see the stats since April/2020, you'll notice that there were full months with 0 or 1 death. [0] Too soon, too small sample to draw such conclusions. [0] For ex., search for "Serrana" in this site: https://especiais.gazetadopovo.com.br/coronavirus/casos-no-brasil-por-cidades/ https://especiais.gazetadopovo.com.br/coronavirus/casos-no-b... edit: typo, should be "april/2020"

deleted 5y ago
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seanmcdirmid 5y ago
The end of winter probably has a lot to do with it also (just like flu deaths go down during the spring and summer). The vaccines effectiveness probably won’t show through very visibly until November.
- brlewis 5y ago
  With Brazil being on the equator and mostly south of it, I doubt the end of northern hemisphere winter has much to do with it.
  - cesarb 5y ago
    > With Brazil being on the equator and mostly south of it Brazil is a huge country. The city in question is a long way south of the equator, it's near the tropic of Capricorn.
    - renatovico 5y ago
      It’s start of Winter here, i live 100km from serrana
  - thu2111 5y ago
    Seasonality isn't really understood at all by epidemiologists, so it's probably best to confine discussion of it to the places where it's clearly visible, which is mostly the northern hemisphere indeed.

void_mint 5y ago

I am _shocked_.

godmode2019 5y ago

This is a Chinese vaccine, probably looking for good western PR. Since the dates where omitted one can safely assume they timed the 2nd jab with the end if a flu season. A quick google shows this is March - April. Covid deaths spike during the flu season. They should realistically compare to average deaths for that time period, rather than comparing flu season deaths to non flu season deaths.

bellyfullofbac 5y ago
Ok Mr. Expert "It's just a flu". Except this is Brazil, which is the southern hemisphere, where flu season is May to October. Quick, find another alternative explanation!
- godmode2019 5y ago
  Maybe you should double check your information before you post. It makes you look like a complete worthless fool. The flu season is a weather event, 'covid' kills more people during this weather event. This weather event just finished in Brazil, its tropical so its more similar to India than Australia.
chapium 5y ago
By publishing scientific research. How dare they.
redis_mlc 5y ago
The parent has a point. If the CCP is involved, they can't report anything negative without retaliation.
shard 5y ago
Is the flu much of a problem this year? I thought the flu infection rate was way down due to social distancing and lockdowns. The comparison you are suggesting might not be an accurate one.
- godmode2019 5y ago

mxcrossr 5y ago

This seems like good news for a country like Bahrain. It’s unfortunate that the Chinese vaccine isn’t as effective as the competition (such that the current ~50% deployment isn’t enough), but getting to 75% is a realistic goal still.

ec109685 5y ago
The vaccine reduced deaths by 95%. It seems pretty effective.

zoom6628 5y ago

Let's hope to see more studies like this. Here in Hong Kong there is a prevailing public view of the vaccines being too new and created too quickly esp the mRNA ones. Public don't understand that mRNA was decades in the making and is engineered which is why available so quickly. The cultivated traditional vaccines took a little longer due to process. But maybe now people will understand the importance of herd immunity because until that is achieved world wide then this pandemic will stay with us. I worry it will be like tuberculosis and hang around amongst the poor and dense populations, further reducing their chances for good quality of life in places with large populations,high density, and prevailing poverty.

AuthorizedCust 5y ago

While I strongly believe in vaccines, I note that the Dallas, Texas (USA) area has seen similar improvements, and we’re hardly a high-vaccination area. Vaccines surely help, but there seems to be an additional force beyond 1. vaccination rates and 2. natural immunity that could be inferred based on data-informed infection rates. Almost every pandemic measure has been eliminated in Texas the past two months, and the fatality, positivity, and hospitalization rates have kept going down. (The state has prevented local jurisdictions from extending measures.) My guess is that asymptomatic infection rates may have been far higher than what the professionals believe or herd immunity happens at considerably lower levels than believed. I don’t know how else to explain this. For backup, here’s various plots I’m making from official state data. The hospitalizations are probably the most reliable metric, and like the other metrics, they are just falling off a cliff. https://www.arencambre.com/covid-19-stats-for-dallas-and-texas/ https://www.arencambre.com/covid-19-stats-for-dallas-and-tex...

ceph_ 5y ago
You really trying to say it isn't the vaccine. When vaccine availability is the only positive thing that changed?
- kapp_in_life 5y ago
  We're also entering the summer months which I hazily remember somehow negatively impacting Covid-19's ability to spread last year.
  - igetspam 5y ago
    I challenge your hazy memory with a "false." Late spring was when we started seeing infections. Summer being hot was what we were told would help. The data showed otherwise. As you've provided none of your own, I'll go ahead and do the same.
    - Izkata 5y ago
      There's a few states where the drop in the summer was really obvious, like Illinois and New York, and others that didn't spike until the fall, like Washington and Montana. Cases being low in the summer is common in the northern states, which is probably what GP is hazily remembering.

akamaka 5y ago

The article doesn’t mention how much natural immunity exists in the community, which is presumably high given the large outbreaks in Brazil. Is there a study which has calculated a more precise herd immunity threshold, taking this effect into account?

pengaru 5y ago

In 2021 are we supposed to be surprised to learn vaccines actually work?

kenneth 5y ago

Pretty impressive result for a vaccine that's been shown to barely have the 50% efficacy threshold to make the cut (and with doubts about its results due to no releasing of trial data). Shows high promise for countries using mRNA vaccines.

Markoff 5y ago

I could make same headline about Czechia - COVID deaths plunge after less than 40% adults vaccinated and warm weather came from 200+ deaths per day we are at <20 deaths