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You might wonder how polio gets reintroduced into Israel or anywhere else. The polio vaccines we currently use are imperfect. The oral vaccine is a weakened fo

You might wonder how polio gets reintroduced into Israel or anywhere else. The polio vaccines we currently use are imperfect. The oral vaccine is a weakened form but it mutates in the neighborhood of one in a million cases to become effectively wild polio and some years this accounts for most of the poliomyelitis cases. On the other hand, the fully inactivated injected vaccine is non-sterilizing: it prevents poliomyelitis but still allows for gut infection. This eradicates the disease but not the virus. This is why they previously found the polio virus in sewage samples even though there were no poliomyelitis cases. Most anger at the un-vaccinated (due to the assumption that they are causing the spread) seems mis-placed since those vaccinated by the injected form (that's probably you commenting on Hacker News!) will spread the polio virus as well.

Fomite 5y ago
This is also somewhat complicated because, as the article notes, sewage monitoring in Israel picks up polio virus with some degree of frequency, despite there being no recorded cases - there's definitely shedding going on, and it's sort of an odd case due to a number of demographic and geopolitical factors. This is not necessarily something that can be attributed to the vaccine. Will be curious to see what the results are if they try to trace it back.
- gregwebs 5y ago
  That's exactly what is expected from a non-sterilizing vaccine. The polio virus will still circulate in the gut of the vaccinated and be visible in sewage, etc even though there are no poliomyelitis cases.
  - ars 5y ago
    Ugh, your post is a terrible mix of true and false, and you keep confusing IPV and OPV. I don't like that it's flagged, since there are elements in there that are true, but you wrote them in such a confusing way (in particular confusing IPV and OPV), that maybe you deserve to be flagged.
- tootie 5y ago
  Does polio not have animal reservoirs?
  - fastaguy88 5y ago
    No. If it could be eliminated from humans, it would be gone. Like smallpox.
    - cdtwigg 5y ago
      The oral polio vaccine is a live vaccine and occasionally reverts to an actually infectious strain. This isn’t a major concern in countries where people are widely vaccinated but would be an issue if we considered it eliminated and stopped vaccinating segments of the population. https://en.m.wikipedia.org/wiki/Polio_vaccine https://en.m.wikipedia.org/wiki/Polio_vaccine
      - gus_massa 5y ago
        After some years without cases and if the country has a high vaccination rate, then the recommendation is to switch to use only the injectable vaccine. More details in the section https://en.wikipedia.org/wiki/Polio_vaccine#Schedule https://en.wikipedia.org/wiki/Polio_vaccine#Schedule
  - Fomite 5y ago
    No. It and measles are currently our two best targets for genuine eradication.
  - manholio 5y ago
    recently it has found a way to spread to dogs, in Chad I believe.
    - manholio 5y ago
      Sorry, misremembered it, it was the Guineea worm.
- ars 5y ago
  Polio keeps being found in sewage in many countries without active cases. The countries that need the sewage monitoring the most, are the ones least likley to have it, so it's probably even worse than it seems.
- Izkata 5y ago
  > despite there being no recorded cases - there's definitely shedding going on > This is not necessarily something that can be attributed to the vaccine. Some stats about polio that people seem unaware of: * Around 72% of infections are completely asymptomatic. * Around 25% of infections result in flu-like symptoms. * That remaining 3% is where the serious symptoms are, with paralysis occurring in only about 0.5% of infections despite being what polio is known for. * Searching for the death rate of polio almost always results in finding "5 to 10 percent" - but that's of paralytic polio, not polio infections in general, so if you want polio infections in general, that's 5% of 0.5%, or around 0.025 - 0.05 percent. https://www.cdc.gov/polio/what-is-polio/index.htm https://www.cdc.gov/polio/what-is-polio/index.htm
  - hef19898 5y ago
    And your point is? That Polio is just a non-serious disease?
    - Izkata 5y ago
      Look at the two lines from the parent comment that I quoted.
  - fragmede 5y ago
    To put that in perspective, to date, Covid-19 has killed 957k Americans. This works out to be 0.3 percent if everyone had it (which they didn't).
    - Izkata 5y ago
      This number is lower than that due to the "with vs from" distinction. The data is really messy though so we can't be sure how much lower.
      - albertopv 5y ago
        A recent italian Istituto Superiore di Sanità study showed that a great majority of people dead with covid died from it or it have been a serious concurrent cause. https://amp24.ilsole24ore.com/pagina/AEbOPLHB https://amp24.ilsole24ore.com/pagina/AEbOPLHB
ckemere 5y ago
This bears some correction. As the article reports, the strain that caused infection was traced from Malawi/Pakistan, where there is still endemic polio because of long-lasting vaccine hesitancy.
- gregwebs 5y ago
  The article doesn't say that this has been traced from anywhere. It just says the Malawi outbreak was traced from Pakistan.
- somenameforme 5y ago
  Some interesting history on Pakistan there that has do with unforeseen consequences and why the ends never really do justify the means. The CIA gained some intel that Bin Laden was residing in Pakistan, and in the precise vicinity, but they wanted to be certain. They way they did this was by recruiting a local doctor [1] and splashing around a ton of money to start a fake vaccine campaign. It's unclear if they bothered using real vaccines or not, but the entire point of the program was a CIA DNA collection program. The CIA was bulk harvesting Pakistani DNA and cross referencing it against DNA from Bin Laden's sister Once it was confirmed that Bin Laden had children in the area, the program was scrapped, we invaded, he was killed, and everybody was left out to to dry. The doctor was imprisoned, charged with treason, and has since been in solitary with claims of torture for going on a decade now [2]. Local aid workers (who had no idea what they were involved in) were hunted down and killed, some districts banned vaccination drives, and Pakistanis have been extremely critical of any sort of vaccination effort since. [1] - https://en.wikipedia.org/wiki/Shakil_Afridi https://en.wikipedia.org/wiki/Shakil_Afridi [2] - https://nationalinterest.org/blog/buzz/ten-years-what-became-cia%E2%80%99s-bin-laden-doctor-shakil-afridi-188452 https://nationalinterest.org/blog/buzz/ten-years-what-became...
  - jcadam 5y ago
    destroying trust has consequences.
  - sitkack 5y ago
    I don't have the emotional resevoir to find the hard numbers, but it is estimated that hundreds of doctors and aid workers have been killed because of this specific CIA action. And it turns it, from the article below, it was to possibly confirm that the compound had Bin Laden, not to actually find him. https://slate.com/human-interest/2011/07/the-cia-s-fake-vaccination-program-in-pakistan-reveals-the-moral-bankruptcy-of-american-spooks.html https://slate.com/human-interest/2011/07/the-cia-s-fake-vacc...
wolverine876 5y ago
> Most anger at the un-vaccinated (due to the assumption that they are causing the spread) seems mis-placed since those vaccinated by the injected form (that's probably you commenting on Hacker News!) will spread the polio virus as well. Seriously. In what population does polio spread, the unnvacinnated or the vaccinated? In what population are you exposed to it?
- mlyle 5y ago
  > In what population does polio spread, the unnvacinnated or the vaccinated? In what population are you exposed to it? This is all so weird. An explanation of how I understand it: Polio definitely spreads in the unvaccinated. If you've given the IPV vaccine, you can later be infected and spread polio (with a little less likelihood), but won't become sick. If you're given the OPV vaccine, you eventually will have sterilizing immunity, and won't spread it, once immunity develops a small time after vaccination. But the OPV vaccine itself very rarely causes polio outbreaks. So the recommendations are complicated. If you're in a part of the world without polio spread, you should be given the IPV vaccine. If you're in a part of the world with endemic polio and a good health system, you should be given the IPV vaccine and then the OPV vaccine a few months later. If you're in a part of the world with endemic polio and a lacking health system, the best bet is just giving you the OPV vaccine.
  - selimthegrim 5y ago
    Weren't there vaccine derived polio cases from the OPV in Pakistan?
    - mlyle 5y ago
      > If you're given the OPV vaccine, you eventually will have sterilizing immunity, and won't spread it, once immunity develops a small time after vaccination. But the OPV vaccine itself very rarely causes polio outbreaks.
      - selimthegrim 5y ago
jeromegv 5y ago
Yes but the vaccinated would have no one to make sick around them if there isn’t anyone unvaccinated around them. Doesn’t matter as much if we all have the virus, as long as it doesn’t develop as a sickness.
moonchild 5y ago
> The polio vaccines we currently use are imperfect Is that due to tradeoffs (cost, health risk, etc.) with other types of vaccines, or do we simply not know how to make them?q
- beagle3 5y ago
  They are non-sterilizing ; that is, they protect the vaccinee from getting the disease, but not from getting (and shedding) the virus. We have sterilizing oral ones. They have safety issues, both personal and population level ones. The essentially perfect way is to give everyone the non-sterilizing one as early as possible in life, and the sterilizing one at a later stage. The non-sterilizing one protects against the safety issues in the sterilizing one.
jqquah 5y ago
Is this where mRNA vaccines can be useful?
- duxup 5y ago
  There already are effective polio vaccines.
- gregwebs 5y ago
  The COVID vaccines suffer from a similar issue. By design they are non-sterilizing because they don't develop immunity in the nasal mucous. It's always been the case that with a large enough exposure the COVID vaccinated would still get infected in the nose and transmit the virus to others.
  - puffoflogic 5y ago
    This is disinformation. If you get the vaccine you won't get COVID. It's that simple.
bsder 5y ago
Part of the problem is that the weakened form is used because it doesn't require refrigeration. So, the fully inactivated vaccine is the "better" of the two, but, because it requires refrigeration, is harder to deal with in the areas of Pakistan and Afghanistan where vaccination is most needed.
legulere 5y ago
Does Israel even use the oral vaccine? As far as I know all countries that have the basic infrastructure that is needed for the injection one, use that one.
- beagle3 5y ago
  For many years, Israel used both - injection, followed by oral a few years later. At some point, it stopped with the oral - but e.g. in 2013 following some increased sewage levels detected, Israel had a population wide oral vaccine drive[0] I'm not quite sure what the schedule is right now, but the heavy handed essentially mandated covid vaccination is reported (so far unofficially, official data not yet released) to have caused a non trivial drop in standard vaccine uptake. Last time Israel had a vaccine mandate was for a short while in the early 50s; Since then, there were no mandate or general requirements e.g. in schools. Uptake was still very high, at over 95% or so until the MMR vaccine scare, which only dented it lightly. Officially and technically, Irsael did not have a covid vaccine mandate - but practically, it did for many people, much like it did in France until a few days ago. [0] https://www.pnas.org/doi/10.1073/pnas.1922746117 https://www.pnas.org/doi/10.1073/pnas.1922746117

Fomite 5y ago

This is also somewhat complicated because, as the article notes, sewage monitoring in Israel picks up polio virus with some degree of frequency, despite there being no recorded cases - there's definitely shedding going on, and it's sort of an odd case due to a number of demographic and geopolitical factors. This is not necessarily something that can be attributed to the vaccine. Will be curious to see what the results are if they try to trace it back.

gregwebs 5y ago
That's exactly what is expected from a non-sterilizing vaccine. The polio virus will still circulate in the gut of the vaccinated and be visible in sewage, etc even though there are no poliomyelitis cases.
- ars 5y ago
  Ugh, your post is a terrible mix of true and false, and you keep confusing IPV and OPV. I don't like that it's flagged, since there are elements in there that are true, but you wrote them in such a confusing way (in particular confusing IPV and OPV), that maybe you deserve to be flagged.
tootie 5y ago
Does polio not have animal reservoirs?
- fastaguy88 5y ago
  No. If it could be eliminated from humans, it would be gone. Like smallpox.
  - cdtwigg 5y ago
    The oral polio vaccine is a live vaccine and occasionally reverts to an actually infectious strain. This isn’t a major concern in countries where people are widely vaccinated but would be an issue if we considered it eliminated and stopped vaccinating segments of the population. https://en.m.wikipedia.org/wiki/Polio_vaccine https://en.m.wikipedia.org/wiki/Polio_vaccine
    - gus_massa 5y ago
      After some years without cases and if the country has a high vaccination rate, then the recommendation is to switch to use only the injectable vaccine. More details in the section https://en.wikipedia.org/wiki/Polio_vaccine#Schedule https://en.wikipedia.org/wiki/Polio_vaccine#Schedule
- Fomite 5y ago
  No. It and measles are currently our two best targets for genuine eradication.
- manholio 5y ago
  recently it has found a way to spread to dogs, in Chad I believe.
  - manholio 5y ago
    Sorry, misremembered it, it was the Guineea worm.
ars 5y ago
Polio keeps being found in sewage in many countries without active cases. The countries that need the sewage monitoring the most, are the ones least likley to have it, so it's probably even worse than it seems.
Izkata 5y ago
> despite there being no recorded cases - there's definitely shedding going on > This is not necessarily something that can be attributed to the vaccine. Some stats about polio that people seem unaware of: * Around 72% of infections are completely asymptomatic. * Around 25% of infections result in flu-like symptoms. * That remaining 3% is where the serious symptoms are, with paralysis occurring in only about 0.5% of infections despite being what polio is known for. * Searching for the death rate of polio almost always results in finding "5 to 10 percent" - but that's of paralytic polio, not polio infections in general, so if you want polio infections in general, that's 5% of 0.5%, or around 0.025 - 0.05 percent. https://www.cdc.gov/polio/what-is-polio/index.htm https://www.cdc.gov/polio/what-is-polio/index.htm
- hef19898 5y ago
  And your point is? That Polio is just a non-serious disease?
  - Izkata 5y ago
    Look at the two lines from the parent comment that I quoted.
- fragmede 5y ago
  To put that in perspective, to date, Covid-19 has killed 957k Americans. This works out to be 0.3 percent if everyone had it (which they didn't).
  - Izkata 5y ago
    This number is lower than that due to the "with vs from" distinction. The data is really messy though so we can't be sure how much lower.
    - albertopv 5y ago
      A recent italian Istituto Superiore di Sanità study showed that a great majority of people dead with covid died from it or it have been a serious concurrent cause. https://amp24.ilsole24ore.com/pagina/AEbOPLHB https://amp24.ilsole24ore.com/pagina/AEbOPLHB

ckemere 5y ago

This bears some correction. As the article reports, the strain that caused infection was traced from Malawi/Pakistan, where there is still endemic polio because of long-lasting vaccine hesitancy.

gregwebs 5y ago
The article doesn't say that this has been traced from anywhere. It just says the Malawi outbreak was traced from Pakistan.
somenameforme 5y ago
Some interesting history on Pakistan there that has do with unforeseen consequences and why the ends never really do justify the means. The CIA gained some intel that Bin Laden was residing in Pakistan, and in the precise vicinity, but they wanted to be certain. They way they did this was by recruiting a local doctor [1] and splashing around a ton of money to start a fake vaccine campaign. It's unclear if they bothered using real vaccines or not, but the entire point of the program was a CIA DNA collection program. The CIA was bulk harvesting Pakistani DNA and cross referencing it against DNA from Bin Laden's sister Once it was confirmed that Bin Laden had children in the area, the program was scrapped, we invaded, he was killed, and everybody was left out to to dry. The doctor was imprisoned, charged with treason, and has since been in solitary with claims of torture for going on a decade now [2]. Local aid workers (who had no idea what they were involved in) were hunted down and killed, some districts banned vaccination drives, and Pakistanis have been extremely critical of any sort of vaccination effort since. [1] - https://en.wikipedia.org/wiki/Shakil_Afridi https://en.wikipedia.org/wiki/Shakil_Afridi [2] - https://nationalinterest.org/blog/buzz/ten-years-what-became-cia%E2%80%99s-bin-laden-doctor-shakil-afridi-188452 https://nationalinterest.org/blog/buzz/ten-years-what-became...
- jcadam 5y ago
  destroying trust has consequences.
- sitkack 5y ago
  I don't have the emotional resevoir to find the hard numbers, but it is estimated that hundreds of doctors and aid workers have been killed because of this specific CIA action. And it turns it, from the article below, it was to possibly confirm that the compound had Bin Laden, not to actually find him. https://slate.com/human-interest/2011/07/the-cia-s-fake-vaccination-program-in-pakistan-reveals-the-moral-bankruptcy-of-american-spooks.html https://slate.com/human-interest/2011/07/the-cia-s-fake-vacc...

wolverine876 5y ago

> Most anger at the un-vaccinated (due to the assumption that they are causing the spread) seems mis-placed since those vaccinated by the injected form (that's probably you commenting on Hacker News!) will spread the polio virus as well. Seriously. In what population does polio spread, the unnvacinnated or the vaccinated? In what population are you exposed to it?

mlyle 5y ago
> In what population does polio spread, the unnvacinnated or the vaccinated? In what population are you exposed to it? This is all so weird. An explanation of how I understand it: Polio definitely spreads in the unvaccinated. If you've given the IPV vaccine, you can later be infected and spread polio (with a little less likelihood), but won't become sick. If you're given the OPV vaccine, you eventually will have sterilizing immunity, and won't spread it, once immunity develops a small time after vaccination. But the OPV vaccine itself very rarely causes polio outbreaks. So the recommendations are complicated. If you're in a part of the world without polio spread, you should be given the IPV vaccine. If you're in a part of the world with endemic polio and a good health system, you should be given the IPV vaccine and then the OPV vaccine a few months later. If you're in a part of the world with endemic polio and a lacking health system, the best bet is just giving you the OPV vaccine.
- selimthegrim 5y ago
  Weren't there vaccine derived polio cases from the OPV in Pakistan?
  - mlyle 5y ago
    > If you're given the OPV vaccine, you eventually will have sterilizing immunity, and won't spread it, once immunity develops a small time after vaccination. But the OPV vaccine itself very rarely causes polio outbreaks.
    - selimthegrim 5y ago

jeromegv 5y ago

Yes but the vaccinated would have no one to make sick around them if there isn’t anyone unvaccinated around them. Doesn’t matter as much if we all have the virus, as long as it doesn’t develop as a sickness.

moonchild 5y ago

> The polio vaccines we currently use are imperfect Is that due to tradeoffs (cost, health risk, etc.) with other types of vaccines, or do we simply not know how to make them?q

beagle3 5y ago
They are non-sterilizing ; that is, they protect the vaccinee from getting the disease, but not from getting (and shedding) the virus. We have sterilizing oral ones. They have safety issues, both personal and population level ones. The essentially perfect way is to give everyone the non-sterilizing one as early as possible in life, and the sterilizing one at a later stage. The non-sterilizing one protects against the safety issues in the sterilizing one.

jqquah 5y ago

Is this where mRNA vaccines can be useful?

duxup 5y ago
There already are effective polio vaccines.
gregwebs 5y ago
The COVID vaccines suffer from a similar issue. By design they are non-sterilizing because they don't develop immunity in the nasal mucous. It's always been the case that with a large enough exposure the COVID vaccinated would still get infected in the nose and transmit the virus to others.
- puffoflogic 5y ago
  This is disinformation. If you get the vaccine you won't get COVID. It's that simple.

bsder 5y ago

Part of the problem is that the weakened form is used because it doesn't require refrigeration. So, the fully inactivated vaccine is the "better" of the two, but, because it requires refrigeration, is harder to deal with in the areas of Pakistan and Afghanistan where vaccination is most needed.

legulere 5y ago

Does Israel even use the oral vaccine? As far as I know all countries that have the basic infrastructure that is needed for the injection one, use that one.

beagle3 5y ago
For many years, Israel used both - injection, followed by oral a few years later. At some point, it stopped with the oral - but e.g. in 2013 following some increased sewage levels detected, Israel had a population wide oral vaccine drive[0] I'm not quite sure what the schedule is right now, but the heavy handed essentially mandated covid vaccination is reported (so far unofficially, official data not yet released) to have caused a non trivial drop in standard vaccine uptake. Last time Israel had a vaccine mandate was for a short while in the early 50s; Since then, there were no mandate or general requirements e.g. in schools. Uptake was still very high, at over 95% or so until the MMR vaccine scare, which only dented it lightly. Officially and technically, Irsael did not have a covid vaccine mandate - but practically, it did for many people, much like it did in France until a few days ago. [0] https://www.pnas.org/doi/10.1073/pnas.1922746117 https://www.pnas.org/doi/10.1073/pnas.1922746117