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Medicine Science

In Brazil's Amazon a COVID-19 Resurgence Dashes Herd Immunity Hopes (reuters.com) 134

Posted by msmash from the closer-look dept.
Anthony Boadle, reporting for Reuters: [...] In April and May, so many Manaus residents were dying from COVID-19 that its hospitals collapsed and cemeteries could not dig graves fast enough. The city never imposed a full lockdown. Non-essential businesses were closed but many simply ignored social distancing guidelines. Then in June, deaths unexpectedly plummeted. Public health experts wondered whether so many residents had caught the virus that it had run out of new people to infect. Research posted last week to medRxiv, a website distributing unpublished papers on health science, estimated that 44% to 66% of the Manaus population was infected between the peak in mid-May and August.

The study by the University of Sao Paulo's Institute of Tropical Medicine tested newly donated banked blood for antibodies to the virus and used a mathematical model to estimate contagion levels. The high infection rate suggested that herd immunity led to the dramatic drop in cases and deaths, the study said. Scientists estimate that up to 70 pct of the population may need to be protected against coronavirus to reach herd immunity. In Manaus, daily burials and cremations fell from a peak of 277 on May 1 to just 45 in mid-September, the mayor's office said. The COVID-19 death toll that officially peaked at 60 on April 30 dropped to just two or three a day by late August. Now the numbers are on the rise again.
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In Brazil's Amazon a COVID-19 Resurgence Dashes Herd Immunity Hopes More

In Brazil's Amazon a COVID-19 Resurgence Dashes Herd Immunity Hopes

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  • But what about herd mentality? (Score:5, Funny)

    by spun ( 1352 ) <loverevolutionary&yahoo,com> on Tuesday September 29, 2020 @03:17PM (#60554940) Journal

    Surely herd mentality will save us all!

  • Public health and quarantines are all (Score:5, Insightful)

    by AleRunner ( 4556245 ) on Tuesday September 29, 2020 @03:20PM (#60554950)

    All we have now is public health and cutting of infected nations behind a wall of quarantine until they get their act together. Many countries in Europe succeeded in getting rid of the disease and were under control until they opened their borders, uncontrolled, to diseased nations. Now everybody needs to follow Vietnam, Thailand, Senegal, New Zealand, Ghana and Taiwan.

    These are countries, most of them not islands, most of them not mega rich. From every type of culture, with varied but mostly high levels of freedom. Nothing special, just simple competent countries which have used their knowledge of basic public health measures to almost entirely eliminate the virus.

    • Re:Public health and quarantines are all (Score:5, Informative)

      by thegarbz ( 1787294 ) on Tuesday September 29, 2020 @04:55PM (#60555312)

      Many countries in Europe succeeded in getting rid of the disease and were under control until they opened their borders, uncontrolled, to diseased nations.

      That's quite some ignorant waffle there. Not a single country in Europe ever managed to "get rid of the disease". Nearly all countries in Europe never closed their boarders to diseased nations. Nearly all countries in Europe started getting the second wave rise of cases before any international restrictions actually changed and for most countries in Europe the changes actually were to tighten restrictions rather than lift them.

      Now back in reality, the rise in cases seems to coincide with re-opening the economy, removing local restrictions, and returning kids to school, with some cases being related to inter EU travel which down to some of the more stricken countries, but that was never banned in the first place.

      • Many countries in Europe succeeded in getting rid of the disease and were under control until they opened their borders, uncontrolled, to diseased nations.

        That's quite some ignorant waffle there.

        let's see

        Not a single country in Europe ever managed to "get rid of the disease".

        As an example, Slovakia had long periods with 0 infections per day, especially in June, despite a quite wide scale testing regime. See also Norway, Slovenia and Finland

        Nearly all countries in Europe never closed their boarders to diseased nations.

        To count as a "diseased nation" I would a minimum definition would be e.g. 50 infections per 100,000. The entirety of Europe was below this threshold at one point and at that point they closed the boarders to most of the world, including the USA which was the one country that was clearly failing at that point.

        Nearly all countries in Europe started getting the second wave rise of cases before any international restrictions actually changed and for most countries in Europe the changes actually were to tighten restrictions rather than lift them.

        The EU recommendation [europa.eu]

        • Re: (Score:2)

          by makomk ( 752139 )

          If these stats are accurate [statista.com], Slovakia was testing between a couple of thousand people a day to as low as 41 people during June. It's not terribly surprising that they'd be reporting zero new cases per day on many days during June with that level of testing, especially if the tests were less than ideally targetted.

        • Re: (Score:2)

          by AmiMoJo ( 196126 )

          Scotland came pretty close too, for a few weeks over the summer. Incredible considering they have an open border with England where the virus is running rife.

      • Nearly all countries in Europe never closed their boarders to diseased nations.
        That is nonsense. From March till June all borders were closed.

        • Be specific about which border and which point I made you're talking about.

          As someone who regularly travelled between EU countries during the pandemic I assure no borders were closed, some were controlled but non were closed.
          As someone who has lots of contact with people who travel beyond the EU borders I assure you almost nothing which was previously closed is currently open and all those "closures" both then and now applied only to completely voluntarily travel and didn't actually block any kind of busine

          • All borders inside of the eu were closed for "non essential" traffic.

            If you could pass them, then probably for work. Everything else was closed down.

            • So in otherwords all the borders were completely open, because no one defined or even asked about "essential traffic". Hell you're not even following your own country's policies properly. In the very middle of the pandemic I drove straight through Germany on the E30. There were zero border people to be seen where your A30 joins the Netherlands, there were police standing doing absolutely nothing on the A12 going into Poland. On the way back from Poland I got stopped and asked where I was going, I said Nethe

  • Summary is terrible. (Score:3)

    by bistromath007 ( 1253428 ) on Tuesday September 29, 2020 @03:20PM (#60554952)

    Only the last sentence matches the title. We need more explanation for that part than the way it was before.

  • Story not the same as the headline (Score:3)

    by Kohath ( 38547 ) on Tuesday September 29, 2020 @03:23PM (#60554964)

    The story doesn't really support the headline. They arguably got herd immunity, now maybe that's not good enough. They don’t know yet.

    Notice that none of these news stories ever emphasize the positive possibilities? They almost always seem to cheer for the virus.

    • Re: (Score:3)

      by GuB-42 ( 2483988 )

      I believe they got herd immunity, it is just that herd immunity is not magic.

      Herd immunity just means that the decrease in susceptible people lowers R to less than 1. The virus doesn't have a kill switch that triggers once 70% of the population is infected. Even with herd immunity and vaccines, the virus will continue to be with us for a very long time even when the numbers are small enough for it to stop being a major concern.

      And not only that, Manaus is presumably not an isolated system. So even if it bec

  • No (Score:5, Insightful)

    by Impy the Impiuos Imp ( 442658 ) on Tuesday September 29, 2020 @03:43PM (#60555032) Journal

    Pure sensationalism. No definition of what rise means. Sensationalistic headline when the paper was about whether this city had gotten to herd immunity but the headline suggests herd immunity was achieved but doesn't work omggg!

    Author could would not comment. Still in peer review.

    Article is crap sensationalism nobody but an editor looking for clicks could love.

  • "Numbers are on the rise again" is a bunch of bull (Score:3)

    by iamacat ( 583406 ) on Tuesday September 29, 2020 @03:58PM (#60555092)

    By how much? And why? If death toll dropped from 60 to 2-3 per day, some people will naturally stop taking precautions and get sick. And immunity doesn't have to be permanent to control the pandemic. It could be that most people will get re-exposed within 2-3 months that immunity lasts and get natural boosters. T-cell immunity could last much longer than antibodies and provide protection from severe cases. The whole article seems to be alarmism without proof.

  • Doesn't just dash herd immunity hopes (Score:5, Insightful)

    by smoot123 ( 1027084 ) on Tuesday September 29, 2020 @03:59PM (#60555098)

    TFA didn't touch on this but if we don't develop a long term immunity from actually contracting the disease, what does that say about the efficacy of a vaccine?

    That being said, I'd first caution that "antibodies" are not synonymous with "long term immunity". You can be immune without having antibodies in your blood. Presumably the paper authors know this. I'm less certain about Reuters reporters.

    Second, immune systems are complicated. I'd be pretty surprised you can make a vaccine which is more effective than an actual infection but won't go so far as to say it's impossible. I'm not a doctor, what do I know?

    • I'd be pretty surprised you can make a vaccine which is more effective than an actual infection but won't go so far as to say it's impossible.

      Prepared to be surprised at well-known and overwhelming science!

      Smallpox has been eradicated almost entirely due to vaccinations. The vaccination campaign against polio has been almost as successful. There is an overwhelming negative correlation [wikipedia.org] between measles infection and vaccination rates.

      • COVID19 is a bit different. It initially lives and reproduces on the surface of the lungs. There are no antibodies on the lungs - but there are other means by which your body suppresses infection. Antibodies might prevent you from getting sick and can limit the infection to your lungs but you can still, in theory, contract and transmit COVID19 despite the presence of antibodies.

        I am all for vaccines, but COVID19 is going to be a tough one to manage. The virus actually has to potential of being here f

    • I'd be pretty surprised you can make a vaccine which is more effective than an actual infection but won't go so far as to say it's impossible.

      They are trying to create antibodies to specific proteins that might not naturally end up as targets. They do this by creating fragments of the virus from DNA sequences. This means it's a very different system from an entire virus and entirely possible that it ends up either much weaker or noticeably stronger than natural immunity. There are quite a number of different vaccines being attempted from different approaches so I'd say there's an explicit hope that they could create long term immunity even if

    • TFA didn't touch on this but if we don't develop a long term immunity from actually contracting the disease, what does that say about the efficacy of a vaccine?

      Exactly the same as the efficacy of every other vaccine which is to say how vaccines work and simply having had the virus at some point are two very different things.

    • if we force everyone to take it. The vaccine can work then, because we'd achieve a sudden herd immunity that would overtake the virus. But with 30-40% refusing the vaccine it becomes impossible.

  • The summary isn't clear (Score:5, Informative)

    by rsilvergun ( 571051 ) on Tuesday September 29, 2020 @04:09PM (#60555160)
    it leaves out why Herd Immunity is unlikely to work:

    University of Sao Paulo researchers suggested that a drastic fall in COVID-19 deaths in Manaus pointed to collective immunity at work, but they also believe that antibodies to the disease after infection may not last more than a few months.

    The summary did mention one critical thing, which is that cases are going back up in the city (as on poster already noted they're leveling off in Brazil as a whole, but the spot that matters is this city because they're at the "herd immunity" numbers).

    So this city is at the point where they should be seeing case drops due to H.I. but they're not. And it's very likely because immunity only lasts a short while.

    This also means a vaccine is useless in countries like America where 30-40% will refuse to take it. The only way a vaccine can work is that if everybody gets it save the very, very immunocompromised. Here in the states you'll have numbskulls in their 20s that go rock climbing on the weekend claiming "I'm immunocompromised!". Doesn't help that anti-vax is a political issue here. >
    TL;DR; baring a miracle America is going to be awash in pandemic for 2-4 years thanks to human stupidity.

    • Re:The summary isn't clear (Score:4, Insightful)

      by dgatwood ( 11270 ) on Tuesday September 29, 2020 @04:37PM (#60555268) Homepage Journal

      So this city is at the point where they should be seeing case drops due to H.I. but they're not. And it's very likely because immunity only lasts a short while.

      Or it is because people have stopped being scared to go to the city, so you're getting new people who don't have immunity. Also, even with antibodies, immunity is not 100%. You can still get the disease even with antibodies; you're just less likely to get it and considerably less likely to have a severe case of it.

      This also means a vaccine is useless in countries like America where 30-40% will refuse to take it. The only way a vaccine can work is that if everybody gets it save the very, very immunocompromised.

      That depends on the mutation rate. A virus with a low mutation rate can burn itself out in a larger non-immunized subpopulation than a virus whose mutation rate is high. That's why there's at least a chance of success of using vaccines to eliminate COVID-19 in spite of the anti-vaxxers, unlike with influenza, where you'd have to basically hit 100% coverage worldwide.

      That said, if the vaccine is useless in America, it's also useless in the rest of the world unless all travel from America is permanently banned.

      Oh, and one other thing you missed is that immunization, even long after antibodies are gone, can have a significant impact on your body's response to a virus (for better or worse). So there's some possibility that vaccination will significantly reduce mortality among the vaccinated long after the antibodies are gone and the virus has mutated to the point that the vaccine no longer prevents infection. So even if the virus only eliminates the 70% of deaths that would occur in non-anti-vaxxers, it would still be a huge win.

      • can instantly cause another outbreak then Herd Immunity doesn't work. The virus will just go round and round and every time a community gets close their population will hit the 3-4 month mark where it's vulnerable again and we're back to square one.

        Worse actually, because the virus is likely to mutate, and not the good "mutate to be less lethal" way but bad as in "mutate to spread faster".

        Europe & Canada are both way ahead of you on banning Americans.
        • it's looking increasingly like this virus does a lot of damage to survivors. It hits pretty much every part of your body. Most importantly it hits the brain & key parts of your lungs. Both of which don't heal. Ever.

          So we need to stop talking about just "death" and consider the ones who don't die, but are permanently maimed.
          • I've read before, that it causes permanent lung damage.  My question is, how can anyone possibly know the effects are "permanent"?

            • Because COVID-19 attacks the lungs with a sharpie.

            • I've read before, that it causes permanent lung damage. My question is, how can anyone possibly know the effects are "permanent"?

              Because the tissues that are being damaged, are the kinds that the body doesn't repair?

        • Re: (Score:2)

          by dgatwood ( 11270 )

          can instantly cause another outbreak then Herd Immunity doesn't work.

          No, I meant that people from the other areas could be the ones getting sick.

          • that's clear from the context of Brazil's overall numbers going down and the numbers in the city going up.

            The point the researchers are making is that that cases in the city are going up even though they should be at numbers that would indicate Herd Immunity.

            That point wouldn't even make sense if they were talking about the country as a whole or even the surrounding area.

            • Re: (Score:2)

              by dgatwood ( 11270 )

              Does the study ask the sick people, "Were you living here six months ago?"

              My point is that an influx of people changes the percentage of people who are immune, and those new people coming in are not immune. And they're coming into a high-density area that makes spreading a contagion extremely easy, and in particular, a high-density area where that contagion is known to be spreading.

              The surrounding state as a whole isn't anywhere close to herd immunity levels:

              Amazonas state population: 3.874 million
              Amaz

  • We should thank Brazil for testing these theories so we don't have to...hopefully.

    • Re: (Score:2)

      by higuita ( 129722 )

      Brazil, India and USA are the world Guinea Pigs... THANK YOU !!

      • Brazil, India and USA are the world Guinea Pigs... THANK YOU !!

        Don't thank them too much. These countries are also the viruses petri dish where it gets to try new mutations and eventually find ones which allow it to overcome whatever forms of immunity we develop. If all the countries in the world were as sensible as Vietnam over this virus then we simply wouldn't have a problem.

        • Re: (Score:2)

          by dryeo ( 100693 )

          Vietnam recently let some business people in and now their cases are going up. It's hard to seal off a country.

    • We should thank the USA for providing a Worst Case baseline for comparison. When testing the effectiveness of treatments we need the placebo to test against.

  • Now the numbers are on the rise again.

    And those numbers are... nowhere to be found anywhere in the article. So I guess we'll just have to take their word for it. Why are writers so lazy?

  • I dont get it.... (Score:4, Insightful)

    by aXis100 ( 690904 ) on Tuesday September 29, 2020 @07:26PM (#60555700)

    I don't understand why people are pushing naturally acquired herd immunity as a valid valid strategy.

    In order to reach immunity without a vaccine, you have to let 70 - 90% of your population catch the disease - the one we are trying to avoid. You then have to accept the fatalities and long term complications across that 70-90%, a staggering number of casualties.

    A *disturbing* number of people seem to be OK with that kind of collateral damage versus just staying home and/or wearing masks for a couple of months. Has society become less compassionate, or is it a product of some countries not having a social security safety net.

    • From what I've seen, a lot of anti-mask people seem to be under the impression that the masks are supposed to protect them, so the whole moral/ethics/freedom thing is reversed in their thinking, i.e. "You can't force me to wear a mask if I don't want to!" type of thing.

    • Re: (Score:2)

      by khchung ( 462899 )

      I don't understand why people are pushing naturally acquired herd immunity as a valid valid strategy.

      Because they think it will always be *other people* dying, and unfortunately, over 90% of them would be proven correct in the end.

      It seemed that people in some countries are ok with 1-5% of their population dying, while people in some other countries are not ok with it if lockdown/quarantine/masks/social distancing can prevent it.

    • Re: (Score:2)

      by makomk ( 752139 )

      Probably because herd immunity is what would normally end a pandemic like this one, and the idea of stopping a respiratory disease with characteristics so unfavourable to any kind of containment as Covid-19 is basically completely unprecedented and untested. Staying home and/or wearing masks for a couple of months is absolutely not close to enough - most of Europe already tried that, and all it did was delay things for a few months at vast, unbelievable costs.

    • Herd Immunity is the only valid strategy, that's why.

      You can vaccinate everyone (with an untested, rushed-to-market vaccine that usually takes years, if not decades to develop) and you end up with 70% of the population immune to the virus - which is herd immunity.

      The idea here is that you let the people who are not going to be affected (ie the young, where we have seen in statistics that the death rate is minimal to insignificant for those under 65) "vaccinate" themselves with the live virus to get the same

  • Sorry, the Slashdot AI got confused with the mention of "Amazon"...

  • This is a bit of a long shot to explain the Manaus data, but here goes...

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