11 ms·

Vaccine-derived poliovirus type 2 detected in London, UK

147 points by flave 4y ago

user_7832 4y ago
An interesting tidbit I haven't seen being mentioned - there's a polio oral vaccine, and an injection, but while the oral drops are much cheaper (and have lesser side effects), there's also a small chance of actually passing the virus.
- zubiaur 4y ago
  And the oral vaccine, which is not a killed virus, passes through feces.
- avs733 4y ago
  To clarify...you are referring to the method of vaccine administration not the type of vaccine. Live attenuated viruses create viral shedding, which creates a chance of passing the virus and are administered using oral drops. Inactivated virus vaccines, do not create viral shedding, cannot pass off the virus, and are administered using an injection. In general, attenuated viruses have the potential to create viral shedding and by extension pass on an infection. The fact that the live attenuated polio vaccine is done via drops is a secondary design decision for , gut immunity, shelf stability, ease of administration, etc. That it is oral drops itself does not cause the chance of passing on the virus. Ars technica had a fairly thorough article about all this: https://arstechnica.com/science/2022/06/poliovirus-may-be-spreading-in-london-virus-detected-in-sewage-for-months/ https://arstechnica.com/science/2022/06/poliovirus-may-be-sp...
anotherhue 4y ago
What is a vaccine-derived poliovirus? A vaccine-derived poliovirus (VDPV) is a strain of the weakened poliovirus that was initially included in oral polio vaccine (OPV) and that has changed over time and behaves more like the wild or naturally occurring virus. https://www.cdc.gov/vaccines/vpd/polio/hcp/vaccine-derived-poliovirus-faq.html https://www.cdc.gov/vaccines/vpd/polio/hcp/vaccine-derived-p... Notably, this isn't someone reverse engineering polio from vaccines. (it's still endemic so no need) Although arguably that's exactly what the virus did itself.
- fuckyah 4y ago
- andrewclunn 4y ago
  - dilap 4y ago
    There's some reason to believe that live vaccines may be net better for you, due to beneficial "non-specific" effects. See e.g. https://en.wikipedia.org/wiki/Non-specific_effect_of_vaccines#Live_attenuated_versus_inactivated_vaccines https://en.wikipedia.org/wiki/Non-specific_effect_of_vaccine... which links to https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2994348/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2994348/
  - bigDinosaur 4y ago
    Historically you probably would have preferred the live virus versions to nothing, though. Now it's easier to make the decision you have because vaccine technology has improved so much. It's a reasonable position, although you'd probably still take a live viral vaccine if the disease was otherwise incredibly dangerous and no alternative vaccine existed.
    - tialaramex 4y ago
      It's not a "decision" in a practical sense for the vast majority of HN readers. Imagine I go to a Burger King, and I declare, "Well, I shan't purchase a Big Mac. No, on principle I demand the Whopper". Sure enough the Burger King employees sell me a Whopper. But, that's not because they respect my principled stance against the Big Mac, they don't sell Big Macs and they do sell Whoppers. Rich industrialised countries have all eliminated Polio, and thus don't offer OPV at all. I had OPV when I was a child, because I am an old man but the younger people I work with all had IPV. There was no "Which do you want?" question, government policy changed after elimination and availability of a killed vaccine.
  - tialaramex 4y ago
baybal2 4y ago
laputan_machine 4y ago
In the UK as a child you are offered the Polio vaccine. Uptake is around 95% in the UK overall, and 91% in London. > “Vaccine-derived poliovirus has the potential to spread, particularly in communities where vaccine uptake is lower,” said Dr Vanessa Saliba, consultant epidemiologist at the UKHSA. https://www.theguardian.com/society/2022/jun/22/polio-uk-public-health-officials-declare-national-incident-over-poliovirus https://www.theguardian.com/society/2022/jun/22/polio-uk-pub...
- LatteLazy 4y ago
  It's worth remembering that London is 10m people over a huge area. There are 1001 communities within it. So a 91% overall rate could be 91% everywhere or 99% in many places and 0% in a few. Or anywhere in between. The actual numbers seem to be here: https://data.london.gov.uk/dataset/immunisation-rates-children-1st-2nd-and-5th-birthdays https://data.london.gov.uk/dataset/immunisation-rates-childr... But I am at work so can't really look. Time for me to get a booster maybe...
  - Arnt 4y ago
    That's data for 1, 2 and 5-year-olds. Not for immigrants who arrived at an older age, of which there are quite a few in some parts of London.
    - ClumsyPilot 4y ago
      polio vaccine is reasonably widespread, I don't expect that most proffeshional immigrants would be missing it. i woupd be more concerned about the recent trend of 'conciencious objection' against vaccines GPs could do a better job of asking for your vaccine record and actually checking if its up to date though. I only found out that one of my vaccines was outdated (they need to be done again every 10 years) because I spesifically was checking my vaccines for travel.
    - Zenst 4y ago
      Indeed, London is home to many French nationals, so many that https://www.bbc.co.uk/news/magazine-18234930 https://www.bbc.co.uk/news/magazine-18234930 So the history of vacinations do become blurred. Actualy for France polio was still not eradicated as of 1988, not so in 2020 but how they count that and what the vaccine uptake was for the generations who have migrated is always going to be a factor. https://www.cdc.gov/polio/progress/index.htm https://www.cdc.gov/polio/progress/index.htm Then tourists - London does get a fair few as well, and as covid has shown, virus's dont' hang about.
Havoc 4y ago
On the plus side, I'm glad to hear London has active sewerage surveillance in place
- BoxOfRain 4y ago
  I just wish our water companies weren't cheerfully dumping raw sewage into the Thames like it's a serious commitment to the Victorian steampunk aesthetic.
  - deadbunny 4y ago
    Not just the Thames, it's happening everywhere.
    - tialaramex 4y ago
      Not everywhere. Most of the industrialised world does not build new combined sewers. So if you live in a city that didn't exist say, fifty years ago, the storm water sewers and foul water sewers have always been separate, and as a result there's no Combined Sewer Overflow. Some US cities in the middle are like this, nobody (to a first approximation) lived there in 1901, and today there may be a small city with an airport and a decent night life. But in Europe, and on the US coasts, the cities are older. In theory, you can separate existing combined sewers. For a town you could maybe attempt this as a large local infrastructure project over the course of a year or two, in a small city this is a large and expensive project that could take decades to complete. For somewhere like London or San Francisco it's unthinkably costly and won't be attempted in the foreseeable future. A small sign of willingness to attempt this, combined with the difficult reality of such work goes like this, I live in Southampton, an important port city on England's south coast: 1. Legally, if you fit a new grey water waste (e.g. from a shower, or a washing machine), it should flow into the sanitary sewer, which your home is plumbed into usually via large black pipes that run mostly vertically up the side of the building. It must not flow into the storm water sewer, which is often smaller rectangular pipes connecting to the gutter where they collect roof water. 2. But, there's probably a gutter pipe right near where your waste is, while the sanitary sewer could be on the far side of the property. So, does the plumber do the extra work, and charge you for it? Or do they just cut into the storm water sewer and save their time and your money? 3. Result: Now if you separate the storm water sewer, it has grey water waste flowing into it, and you're dumping that into the sea. Oops.
2-718-281-828 4y ago
What does "vaccine-derived" mean? What is the relation between the detected virus and the virus used in vaccines?
- Fomite 4y ago
  In countries that struggle with polio vaccination, we often use a "live attenuated" vaccine - that is, you are getting an infection with live virus, but one that has been engineered to cause little to no disease. The advantages of this are that it's very easy to administer (this is the classic "vaccine dropper onto a kid's tongue" image), and because you shed the attenuated virus, you can help boost the immunity of those who aren't directly vaccinated. The downside is for the polio vaccine that it occasionally reverts back to a type that causes active disease. This is rare, but definitely happens, and this is one of those cases.
- M2Ys4U 4y ago
  There are two types of vaccine in use: An inactivated virus and live, attenuated virus. Very occasionally the attenuated virus version can cause onward polio infections, i.e. the vaccinated individual can pass the virus on to others.
  - arghwhat 4y ago
    *in use for polio. Many other types of vaccine exist, and modern vaccines tend to be neither inactivated nor attenuated virus.
  - FartyMcFarter 4y ago
    Unfortunately some people will assume that all vaccines are the same type as this one, and they'll use this as an argument for why vaccines are bad :(
    - plsbenice34 4y ago
      Hopefully some people will realise that all vaccines do entail risks, too
wozniacki 4y ago
It looks it stems from pockets of London inhabited by communities historically resistant vaccination and/or a traveler from a country historically resistant to vaccination who has traveled there. UK Health Security Agency (UKHSA) experts believe a traveller – likely from Pakistan, Afghanistan or Nigeria - shed the virus in their stools after being given the oral polio inoculation.[1][2] It is likely the virus was shed by someone who was recently vaccinated against polio in a country where it has not yet been eradicated, such as Pakistan, Afghanistan or Nigeria.[3] [1] First outbreak of highly infectious polio detected in UK since 1984 – the 6 signs to know https://www.the-sun.com/health/5615177/first-outbreak-highly-infectious-polio-uk-signs/ https://www.the-sun.com/health/5615177/first-outbreak-highly... [2] National incident declared after polio detected in London sewage https://www.youtube.com/watch?v=tz7zsLJqZ7M https://www.youtube.com/watch?v=tz7zsLJqZ7M [3] Traces of polio virus found in London sewage as health officials declare national incident https://news.sky.com/story/traces-of-polio-virus-found-in-london-sewage-as-health-officials-declare-national-incident-12638443 https://news.sky.com/story/traces-of-polio-virus-found-in-lo...
- krageon 4y ago
  Honestly folks on holiday without vaccinations against such things should not be allowed to move around. It's already bad that they don't care to protect their own community.
  - vidarh 4y ago
    In this case the virus is a result of one of the polio vaccines. Whomever brought it would very possibly have done the right thing and gotten vaccinated recently, but the live attenuated polio vaccine very occasionally leads to shed attenuated polio virus reverting to full strength.
    - krageon 4y ago
      And that's definitely the reason they didn't get vaccinated, which probably wasn't fundamentally egocentric at all /s
sph 4y ago
Possibly dumb question: what's the risk for a European adult that has done all his vaccines since childhood?
- mateo1 4y ago
  I'm concerned too, I don't think I was offered a polio vaccine, ever.
  - ricardobayes 4y ago
    You probably were, it is part of the mandatory course administered to children (at least it was/is in Central/Eastern Europe)
    - mateo1 4y ago
      Turns out I didn't remember it because it's part of those combined vaccines. I hope my immune memory is better than my cerebral.
      - ggm 4y ago
        You can get an adult booster. I was a recipient of pink sugar cube, possibly Salk vaccine in the 60s. I got a booster with my son's series in the 90s.
    - bjoli 4y ago
      Building on this, the vaccination programmes of the EU countries have converged to the extent that I was able to vaccinate my 3 month old in accordance to the Swedish vaccination programme while on vacation in Portugal by just showing up at a health centre and asking for a vaccination in accordance to their vaccination programme. They even use the same vaccines. If you are younger than 30 you will have had a polio vaccine if you parents followed the national vaccine programme in any European country. If you are younger than 50 chances are that you have been vaccinated as well.
  - baggsie 4y ago
andy_ppp 4y ago
If I’ve had the vaccine as a child and possibly a booster around 15 years ago should I get a booster now?
- 6nf 4y ago
  Doesn't seem to be recommended unless you're actually going to be working with polio patients or something. Childhood vaccine is sufficient.
- avs733 4y ago
  >Two doses of inactivated polio vaccine (IPV) are 90% effective or more against polio; three doses are 99% to 100% effective. >It is not known how long people who received IPV will be immune to poliovirus, but they are most likely protected for many years after a complete series of IPV. https://www.cdc.gov/vaccines/vpd/polio/hcp/effectiveness-duration-protection.html https://www.cdc.gov/vaccines/vpd/polio/hcp/effectiveness-dur...
lol768 4y ago
I understand that the vaccine-derived poliovirus originates from the live/attenuated virus used in the oral vaccine. (Or at least, first-gen versions of it! Does nOPV2 conclusively address these issues?) Can anyone explain why it's rare for inactivated vaccines to be able to be delivered via the oral route? It would have been a lot more efficient/user-friendly to deliver the Coronavirus vaccinations in this manner, but almost all of the vaccines we seem to use nowadays appear to be intramuscular injections.
- sushibowl 4y ago
  There are two main challenges to developing an effective oral vaccine: * designing a formulation that can survive the harsh gastrointestinal environment. For example, COVID-19 vaccines, especially the mRNA-based ones, are especially fragile and degrade rapidly at room temperature even under normal conditions. * Avoiding mucosal tolerance. Many antigens that would evoke an immediate immune response if encountered in the blood stream are ignored by mucus tissue, to avoid your body creating hundreds or thousands of spurious immune responses every day to antigens occurring in your food. For an oral vaccine to be effective it must get around this tolerance to provoke an effective immune response. For respiratory viruses, another promising delivery method would be intranasal, and indeed there are some COVID-19 vaccines in development that use this route[1]. The bottom line is, developing vaccines is already complicated and costly, so unless there is a guaranteed large market demand pharmaceutical companies are unlikely to invest in delivery methods that add additional research challenges. [1] https://www.gavi.org/vaccineswork/covid-19-vaccines-could-squirt-nose-be-just-good-shot-arm https://www.gavi.org/vaccineswork/covid-19-vaccines-could-sq...
  - lol768 4y ago
    Thanks for taking the time to explain these challenges!
- avs733 4y ago
  To wildly summarize...for the same reason you are not CONSTANTLY sick. your stomach is a pretty good, but not perfect, immunodefense - i.e., the stomach is a pretty tough environment for survival. whether it is worth the trouble also depends on the method of infection. The live attenuated oral polio vaccine creates gut immunity, which is helpful because polio is passed via ingestion of infected materials. Gut immunity is less useful if a disease is passed via inhalation. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6132247/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6132247/
deleted 4y ago
[deleted]
shadowgovt 4y ago
Interesting. The tricky thing about finding it in London is that since they found it in sewage sampling, they don't yet know if it originated from the UK's vaccine program or an international source. They'll have to do more digging to narrow it down. EDIT: as per peer comment from the UKHSA, it's believed to be from an international traveler or resident from a country where polio is still endemic and not yet eradicated. This is a good reminder to keep up on one's vaccinations, as herd immunity statistics are impacted by ubiquitous international travel.
- Fomite 4y ago
  Given the UK's vaccine program uses the inactivated vaccine form, it's almost certainly an import case.
gregwebs 4y ago
If you understand the limitations of the two types of vaccines, this story is just something that should be expected to happen. Someone traveled from a country where the weakened live version is given to the UK. This live version mutated in that individual to become transmissible (this mutation happens in around one in a million individuals). The UK vaccinates with the non-live version. This non-live version cannot mutate, but it is non-sterilizing- the vaccinated can still become infected in their gut- the vaccine prevents it from getting into their bloodstream and become poliomyelitis. We now we see this outcome in the sewage samples.
- lamontcg 4y ago
  TWiV was discussing this concept awhile back and mentioned the fact that if someone looked for poliovirus in NYC sewer samples that it would certainly turn up. There's a sort of ethical problem here because if you find it you immediately make a big splash and headlines over something entirely expected and not terribly worrisome. They were leaning towards that you just shouldn't look for it -- it doesn't really add anything to science because virologists who study polio knew it'd be there and everyone else would freak out. Well, now we're there more or less.
- makomk 4y ago
  It's not even really that the live version mutated to become transmissible, exactly - the live oral polio vaccine is reasonably transmissible through the usual fecal-oral route full stop. The problem is that as it spreads through a community the vaccine virus - and especially the type 2 poliovirus - tends to mutate in ways that undo the attenuation which allows it to safely be used as a vaccine and cause it to spread, paralyze and kill in the same way that wild-type polio virus does. Viruses with these kind of mutations have been circulating in the developing world for some time and there seems to be concern they may now be in the UK. (In fact this is the only kind of type 2 poliovirus in circulation these days - the wild version of it was eradicated a few years ago. There were a bunch of celebratory announcements of this that made it to HN which were probably rather premature. The WHO and their partners had a fancy endgame plan for this involving pulling the type 2 component of the vaccine, at which point it would go extinct for real and we'd no longer have to deal with it. This plan failed spectacularly.)
scotty79 4y ago
I think we should move to mRNA technology for most of our vaccines.
hulitu 4y ago
> It is important that all countries, in particular those with a high volume of travel and contact with polio-affected countries and areas, strengthen surveillance in order to rapidly detect any new virus importation and to facilitate a rapid response. If the virus is vaccine derived, shouldn't they search for the vaccine which is causing it ?
- Fomite 4y ago
  They know the vaccine that's causing it - this isn't new, it's just very rare in a country that predominantly administers the inactivated vaccine. This is just the result of the joint probability of someone recently being vaccinated with the live attenuated vaccine, being in London (likely traveling there), and the vaccine converting to a more pathogenic type.
raffraffraff 4y ago
A few months back my wife told me something about polio that I never knew... Polio emerged as an epidemic after the introduction of sanitation. The reason is that polio doesn't have such a terrible effect on infants, so the entire population has been exposed to it as babies and had developed immunity. So while sanitation reduced a lot of other horrible diseases that come from contaminated water, it prevented the population from getting this natural immunity in childhood, leading to an epidemic. And the people who suffered the worst during that time were the more affluent people who would have had better sanitation available to them. Because even though your neighborhood might be clean, you simply couldn't avoid coming in contact with polio in the great mixing bowl of a town or city.
- Cthulhu_ 4y ago
  That's an interesting factoid, thank you for sharing. I've heard related things, e.g. kids who grow up 'too clean' being more susceptible to allergies.

147 points by flave 4y ago

An interesting tidbit I haven't seen being mentioned - there's a polio oral vaccine, and an injection, but while the oral drops are much cheaper (and have lesser side effects), there's also a small chance of actually passing the virus.

zubiaur 4y ago
And the oral vaccine, which is not a killed virus, passes through feces.
avs733 4y ago
To clarify...you are referring to the method of vaccine administration not the type of vaccine. Live attenuated viruses create viral shedding, which creates a chance of passing the virus and are administered using oral drops. Inactivated virus vaccines, do not create viral shedding, cannot pass off the virus, and are administered using an injection. In general, attenuated viruses have the potential to create viral shedding and by extension pass on an infection. The fact that the live attenuated polio vaccine is done via drops is a secondary design decision for , gut immunity, shelf stability, ease of administration, etc. That it is oral drops itself does not cause the chance of passing on the virus. Ars technica had a fairly thorough article about all this: https://arstechnica.com/science/2022/06/poliovirus-may-be-spreading-in-london-virus-detected-in-sewage-for-months/ https://arstechnica.com/science/2022/06/poliovirus-may-be-sp...

anotherhue 4y ago

What is a vaccine-derived poliovirus? A vaccine-derived poliovirus (VDPV) is a strain of the weakened poliovirus that was initially included in oral polio vaccine (OPV) and that has changed over time and behaves more like the wild or naturally occurring virus. https://www.cdc.gov/vaccines/vpd/polio/hcp/vaccine-derived-poliovirus-faq.html https://www.cdc.gov/vaccines/vpd/polio/hcp/vaccine-derived-p... Notably, this isn't someone reverse engineering polio from vaccines. (it's still endemic so no need) Although arguably that's exactly what the virus did itself.

fuckyah 4y ago
andrewclunn 4y ago
- dilap 4y ago
  There's some reason to believe that live vaccines may be net better for you, due to beneficial "non-specific" effects. See e.g. https://en.wikipedia.org/wiki/Non-specific_effect_of_vaccines#Live_attenuated_versus_inactivated_vaccines https://en.wikipedia.org/wiki/Non-specific_effect_of_vaccine... which links to https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2994348/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2994348/
- bigDinosaur 4y ago
  Historically you probably would have preferred the live virus versions to nothing, though. Now it's easier to make the decision you have because vaccine technology has improved so much. It's a reasonable position, although you'd probably still take a live viral vaccine if the disease was otherwise incredibly dangerous and no alternative vaccine existed.
  - tialaramex 4y ago
    It's not a "decision" in a practical sense for the vast majority of HN readers. Imagine I go to a Burger King, and I declare, "Well, I shan't purchase a Big Mac. No, on principle I demand the Whopper". Sure enough the Burger King employees sell me a Whopper. But, that's not because they respect my principled stance against the Big Mac, they don't sell Big Macs and they do sell Whoppers. Rich industrialised countries have all eliminated Polio, and thus don't offer OPV at all. I had OPV when I was a child, because I am an old man but the younger people I work with all had IPV. There was no "Which do you want?" question, government policy changed after elimination and availability of a killed vaccine.
- tialaramex 4y ago

baybal2 4y ago

laputan_machine 4y ago

In the UK as a child you are offered the Polio vaccine. Uptake is around 95% in the UK overall, and 91% in London. > “Vaccine-derived poliovirus has the potential to spread, particularly in communities where vaccine uptake is lower,” said Dr Vanessa Saliba, consultant epidemiologist at the UKHSA. https://www.theguardian.com/society/2022/jun/22/polio-uk-public-health-officials-declare-national-incident-over-poliovirus https://www.theguardian.com/society/2022/jun/22/polio-uk-pub...

LatteLazy 4y ago
It's worth remembering that London is 10m people over a huge area. There are 1001 communities within it. So a 91% overall rate could be 91% everywhere or 99% in many places and 0% in a few. Or anywhere in between. The actual numbers seem to be here: https://data.london.gov.uk/dataset/immunisation-rates-children-1st-2nd-and-5th-birthdays https://data.london.gov.uk/dataset/immunisation-rates-childr... But I am at work so can't really look. Time for me to get a booster maybe...
- Arnt 4y ago
  That's data for 1, 2 and 5-year-olds. Not for immigrants who arrived at an older age, of which there are quite a few in some parts of London.
  - ClumsyPilot 4y ago
    polio vaccine is reasonably widespread, I don't expect that most proffeshional immigrants would be missing it. i woupd be more concerned about the recent trend of 'conciencious objection' against vaccines GPs could do a better job of asking for your vaccine record and actually checking if its up to date though. I only found out that one of my vaccines was outdated (they need to be done again every 10 years) because I spesifically was checking my vaccines for travel.
  - Zenst 4y ago
    Indeed, London is home to many French nationals, so many that https://www.bbc.co.uk/news/magazine-18234930 https://www.bbc.co.uk/news/magazine-18234930 So the history of vacinations do become blurred. Actualy for France polio was still not eradicated as of 1988, not so in 2020 but how they count that and what the vaccine uptake was for the generations who have migrated is always going to be a factor. https://www.cdc.gov/polio/progress/index.htm https://www.cdc.gov/polio/progress/index.htm Then tourists - London does get a fair few as well, and as covid has shown, virus's dont' hang about.

Havoc 4y ago

On the plus side, I'm glad to hear London has active sewerage surveillance in place

BoxOfRain 4y ago
I just wish our water companies weren't cheerfully dumping raw sewage into the Thames like it's a serious commitment to the Victorian steampunk aesthetic.
- deadbunny 4y ago
  Not just the Thames, it's happening everywhere.
  - tialaramex 4y ago
    Not everywhere. Most of the industrialised world does not build new combined sewers. So if you live in a city that didn't exist say, fifty years ago, the storm water sewers and foul water sewers have always been separate, and as a result there's no Combined Sewer Overflow. Some US cities in the middle are like this, nobody (to a first approximation) lived there in 1901, and today there may be a small city with an airport and a decent night life. But in Europe, and on the US coasts, the cities are older. In theory, you can separate existing combined sewers. For a town you could maybe attempt this as a large local infrastructure project over the course of a year or two, in a small city this is a large and expensive project that could take decades to complete. For somewhere like London or San Francisco it's unthinkably costly and won't be attempted in the foreseeable future. A small sign of willingness to attempt this, combined with the difficult reality of such work goes like this, I live in Southampton, an important port city on England's south coast: 1. Legally, if you fit a new grey water waste (e.g. from a shower, or a washing machine), it should flow into the sanitary sewer, which your home is plumbed into usually via large black pipes that run mostly vertically up the side of the building. It must not flow into the storm water sewer, which is often smaller rectangular pipes connecting to the gutter where they collect roof water. 2. But, there's probably a gutter pipe right near where your waste is, while the sanitary sewer could be on the far side of the property. So, does the plumber do the extra work, and charge you for it? Or do they just cut into the storm water sewer and save their time and your money? 3. Result: Now if you separate the storm water sewer, it has grey water waste flowing into it, and you're dumping that into the sea. Oops.

2-718-281-828 4y ago

What does "vaccine-derived" mean? What is the relation between the detected virus and the virus used in vaccines?

Fomite 4y ago
In countries that struggle with polio vaccination, we often use a "live attenuated" vaccine - that is, you are getting an infection with live virus, but one that has been engineered to cause little to no disease. The advantages of this are that it's very easy to administer (this is the classic "vaccine dropper onto a kid's tongue" image), and because you shed the attenuated virus, you can help boost the immunity of those who aren't directly vaccinated. The downside is for the polio vaccine that it occasionally reverts back to a type that causes active disease. This is rare, but definitely happens, and this is one of those cases.
M2Ys4U 4y ago
There are two types of vaccine in use: An inactivated virus and live, attenuated virus. Very occasionally the attenuated virus version can cause onward polio infections, i.e. the vaccinated individual can pass the virus on to others.
- arghwhat 4y ago
  *in use for polio. Many other types of vaccine exist, and modern vaccines tend to be neither inactivated nor attenuated virus.
- FartyMcFarter 4y ago
  Unfortunately some people will assume that all vaccines are the same type as this one, and they'll use this as an argument for why vaccines are bad :(
  - plsbenice34 4y ago
    Hopefully some people will realise that all vaccines do entail risks, too

wozniacki 4y ago

It looks it stems from pockets of London inhabited by communities historically resistant vaccination and/or a traveler from a country historically resistant to vaccination who has traveled there. UK Health Security Agency (UKHSA) experts believe a traveller – likely from Pakistan, Afghanistan or Nigeria - shed the virus in their stools after being given the oral polio inoculation.[1][2] It is likely the virus was shed by someone who was recently vaccinated against polio in a country where it has not yet been eradicated, such as Pakistan, Afghanistan or Nigeria.[3] [1] First outbreak of highly infectious polio detected in UK since 1984 – the 6 signs to know https://www.the-sun.com/health/5615177/first-outbreak-highly-infectious-polio-uk-signs/ https://www.the-sun.com/health/5615177/first-outbreak-highly... [2] National incident declared after polio detected in London sewage https://www.youtube.com/watch?v=tz7zsLJqZ7M https://www.youtube.com/watch?v=tz7zsLJqZ7M [3] Traces of polio virus found in London sewage as health officials declare national incident https://news.sky.com/story/traces-of-polio-virus-found-in-london-sewage-as-health-officials-declare-national-incident-12638443 https://news.sky.com/story/traces-of-polio-virus-found-in-lo...

krageon 4y ago
Honestly folks on holiday without vaccinations against such things should not be allowed to move around. It's already bad that they don't care to protect their own community.
- vidarh 4y ago
  In this case the virus is a result of one of the polio vaccines. Whomever brought it would very possibly have done the right thing and gotten vaccinated recently, but the live attenuated polio vaccine very occasionally leads to shed attenuated polio virus reverting to full strength.
  - krageon 4y ago
    And that's definitely the reason they didn't get vaccinated, which probably wasn't fundamentally egocentric at all /s

sph 4y ago

Possibly dumb question: what's the risk for a European adult that has done all his vaccines since childhood?

mateo1 4y ago
I'm concerned too, I don't think I was offered a polio vaccine, ever.
- ricardobayes 4y ago
  You probably were, it is part of the mandatory course administered to children (at least it was/is in Central/Eastern Europe)
  - mateo1 4y ago
    Turns out I didn't remember it because it's part of those combined vaccines. I hope my immune memory is better than my cerebral.
    - ggm 4y ago
      You can get an adult booster. I was a recipient of pink sugar cube, possibly Salk vaccine in the 60s. I got a booster with my son's series in the 90s.
  - bjoli 4y ago
    Building on this, the vaccination programmes of the EU countries have converged to the extent that I was able to vaccinate my 3 month old in accordance to the Swedish vaccination programme while on vacation in Portugal by just showing up at a health centre and asking for a vaccination in accordance to their vaccination programme. They even use the same vaccines. If you are younger than 30 you will have had a polio vaccine if you parents followed the national vaccine programme in any European country. If you are younger than 50 chances are that you have been vaccinated as well.
- baggsie 4y ago

andy_ppp 4y ago

If I’ve had the vaccine as a child and possibly a booster around 15 years ago should I get a booster now?

6nf 4y ago
Doesn't seem to be recommended unless you're actually going to be working with polio patients or something. Childhood vaccine is sufficient.
avs733 4y ago
>Two doses of inactivated polio vaccine (IPV) are 90% effective or more against polio; three doses are 99% to 100% effective. >It is not known how long people who received IPV will be immune to poliovirus, but they are most likely protected for many years after a complete series of IPV. https://www.cdc.gov/vaccines/vpd/polio/hcp/effectiveness-duration-protection.html https://www.cdc.gov/vaccines/vpd/polio/hcp/effectiveness-dur...

lol768 4y ago

I understand that the vaccine-derived poliovirus originates from the live/attenuated virus used in the oral vaccine. (Or at least, first-gen versions of it! Does nOPV2 conclusively address these issues?) Can anyone explain why it's rare for inactivated vaccines to be able to be delivered via the oral route? It would have been a lot more efficient/user-friendly to deliver the Coronavirus vaccinations in this manner, but almost all of the vaccines we seem to use nowadays appear to be intramuscular injections.

sushibowl 4y ago
There are two main challenges to developing an effective oral vaccine: * designing a formulation that can survive the harsh gastrointestinal environment. For example, COVID-19 vaccines, especially the mRNA-based ones, are especially fragile and degrade rapidly at room temperature even under normal conditions. * Avoiding mucosal tolerance. Many antigens that would evoke an immediate immune response if encountered in the blood stream are ignored by mucus tissue, to avoid your body creating hundreds or thousands of spurious immune responses every day to antigens occurring in your food. For an oral vaccine to be effective it must get around this tolerance to provoke an effective immune response. For respiratory viruses, another promising delivery method would be intranasal, and indeed there are some COVID-19 vaccines in development that use this route[1]. The bottom line is, developing vaccines is already complicated and costly, so unless there is a guaranteed large market demand pharmaceutical companies are unlikely to invest in delivery methods that add additional research challenges. [1] https://www.gavi.org/vaccineswork/covid-19-vaccines-could-squirt-nose-be-just-good-shot-arm https://www.gavi.org/vaccineswork/covid-19-vaccines-could-sq...
- lol768 4y ago
  Thanks for taking the time to explain these challenges!
avs733 4y ago
To wildly summarize...for the same reason you are not CONSTANTLY sick. your stomach is a pretty good, but not perfect, immunodefense - i.e., the stomach is a pretty tough environment for survival. whether it is worth the trouble also depends on the method of infection. The live attenuated oral polio vaccine creates gut immunity, which is helpful because polio is passed via ingestion of infected materials. Gut immunity is less useful if a disease is passed via inhalation. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6132247/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6132247/

deleted 4y ago

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shadowgovt 4y ago

Interesting. The tricky thing about finding it in London is that since they found it in sewage sampling, they don't yet know if it originated from the UK's vaccine program or an international source. They'll have to do more digging to narrow it down. EDIT: as per peer comment from the UKHSA, it's believed to be from an international traveler or resident from a country where polio is still endemic and not yet eradicated. This is a good reminder to keep up on one's vaccinations, as herd immunity statistics are impacted by ubiquitous international travel.

Fomite 4y ago
Given the UK's vaccine program uses the inactivated vaccine form, it's almost certainly an import case.

gregwebs 4y ago

If you understand the limitations of the two types of vaccines, this story is just something that should be expected to happen. Someone traveled from a country where the weakened live version is given to the UK. This live version mutated in that individual to become transmissible (this mutation happens in around one in a million individuals). The UK vaccinates with the non-live version. This non-live version cannot mutate, but it is non-sterilizing- the vaccinated can still become infected in their gut- the vaccine prevents it from getting into their bloodstream and become poliomyelitis. We now we see this outcome in the sewage samples.

lamontcg 4y ago
TWiV was discussing this concept awhile back and mentioned the fact that if someone looked for poliovirus in NYC sewer samples that it would certainly turn up. There's a sort of ethical problem here because if you find it you immediately make a big splash and headlines over something entirely expected and not terribly worrisome. They were leaning towards that you just shouldn't look for it -- it doesn't really add anything to science because virologists who study polio knew it'd be there and everyone else would freak out. Well, now we're there more or less.
makomk 4y ago
It's not even really that the live version mutated to become transmissible, exactly - the live oral polio vaccine is reasonably transmissible through the usual fecal-oral route full stop. The problem is that as it spreads through a community the vaccine virus - and especially the type 2 poliovirus - tends to mutate in ways that undo the attenuation which allows it to safely be used as a vaccine and cause it to spread, paralyze and kill in the same way that wild-type polio virus does. Viruses with these kind of mutations have been circulating in the developing world for some time and there seems to be concern they may now be in the UK. (In fact this is the only kind of type 2 poliovirus in circulation these days - the wild version of it was eradicated a few years ago. There were a bunch of celebratory announcements of this that made it to HN which were probably rather premature. The WHO and their partners had a fancy endgame plan for this involving pulling the type 2 component of the vaccine, at which point it would go extinct for real and we'd no longer have to deal with it. This plan failed spectacularly.)

scotty79 4y ago

I think we should move to mRNA technology for most of our vaccines.

hulitu 4y ago

> It is important that all countries, in particular those with a high volume of travel and contact with polio-affected countries and areas, strengthen surveillance in order to rapidly detect any new virus importation and to facilitate a rapid response. If the virus is vaccine derived, shouldn't they search for the vaccine which is causing it ?

Fomite 4y ago
They know the vaccine that's causing it - this isn't new, it's just very rare in a country that predominantly administers the inactivated vaccine. This is just the result of the joint probability of someone recently being vaccinated with the live attenuated vaccine, being in London (likely traveling there), and the vaccine converting to a more pathogenic type.

raffraffraff 4y ago

A few months back my wife told me something about polio that I never knew... Polio emerged as an epidemic after the introduction of sanitation. The reason is that polio doesn't have such a terrible effect on infants, so the entire population has been exposed to it as babies and had developed immunity. So while sanitation reduced a lot of other horrible diseases that come from contaminated water, it prevented the population from getting this natural immunity in childhood, leading to an epidemic. And the people who suffered the worst during that time were the more affluent people who would have had better sanitation available to them. Because even though your neighborhood might be clean, you simply couldn't avoid coming in contact with polio in the great mixing bowl of a town or city.

Cthulhu_ 4y ago
That's an interesting factoid, thank you for sharing. I've heard related things, e.g. kids who grow up 'too clean' being more susceptible to allergies.