The dream of polio eradication might need a rethink | Hacker News Reader

The dream of polio eradication might need a rethink

npr.org

37 pointslxm50 comments

> In a perfect world, health experts say they'd like everyone would get the more expensive polio shot which is incapable of mutating into a dangerous, circulating virus.

but then...

> Mass immunization campaigns with the more expensive yet safer injectable vaccine, he says, are nearly impossible in some of these places. There simply isn't the infrastructure or trained medical staff to carry out such campaigns.

So, let's try to understand this: if we throw a boatload of money onto this problem, is it possible to eradicate polio using that decent, more expensive vaccine?

or... do we have a theoretical misunderstanding of viruses?

If I'm not mistaken both IPV and OPV is applied to children in national immunization problems of developed countries. So there must be something still missing in IPV.

As far as I know, OPV isn't used in childhood immunization programs in developed countries any more, but it used to be and I think every successful polio eradication program in countries where it's no longer endemic relied on it. There's also some evidence that the inactivated vaccine isn't so good at preventing polio from multiplying in people's guts and spreading to others. Is this a problem in practice? There's probably not any way to know for sure. Also, since polio spreads via the oral-fecal route it's obviously going to spread more effectively in developing countries with poor sewage treatment, so what works in the developed world may not work so well elsewhere anyway.

This would seem to suggest that it's not a problem with the vaccine but with the level of sanitation. The one big relevant difference here is that in developed countries we had flush toilets and sewer systems carrying effluent away from the populace, which may not be true in places that still have polio. So OPV could work but doesn't not because it's ineffective but because the polio-rich effluent produced by vaccinated people isn't being carried away from them effectively.

So maybe the best way to eradicate polio is to build sewers and septic systems.

The problem is that money would not be enough. Training people to the level they can inject it would still take incompressible time.

Is time really the bottleneck? Those easy injectors that are used for epipens can be used by anyone. Perhaps there is an option for something like that.

The problem isn't that it takes a lot of skill to inject someone.

The problem is that it takes a lot of community outreach and organization to have people actually show up for a schedule of 4 shots at different ages. https://www.cdc.gov/vaccines/vpd/polio/public/index.html gives the US schedule, four shots at, "2 months old, 4 months old, 6 through 18 months old, and 4 through 6 years old."

We do a LOT to make sure that people have taken those vaccines. Including checking that you have when you enroll in school.

It the required temperature ranges.

Keeping something on ice is much easier than storing at a precise temperature range and not freezing it.

  The oral polio vaccine (OPV)
  ----------------------------

Contains live, attenuated virus

Should be frozen. If thawed but still cold--below 8 C (46 F)--refreeze immediately. Place in freezer on arrival. If thawed and warm--above 8 C (46 F) [1]

Maintain continuously in the frozen state--14 C (7 F) or lower. The vaccine may be refrozen. A maximum of 10 freeze-thaw cycles are permissible provided the total cumulative duration of thaw does not exceed 24 hours, and provided the temperature does not exceed 8 C (46 F) during the period of thaw. [1]

Vaccine in liquid state in unopened dispettes may be used for up to 30 days provided it has been stored at 2 -8 C (35 -46 F). A maximum of 10 freeze- thaw cycles are permissible provided the total cumulative duration of thaw does not exceed 24 hours and provided the temperature does not exceed 8 C (46 F) during the period of thaw. [1]

Cost of $0.11 - $0.20 per dose. [2]

  Inactivated Poliovirus Vaccine (IPV)
  ------------------------------------

Refrigerate immediately on arrival. Store at 2 -8 C (35 -46 F). Do not freeze. [1]

Should not be frozen. Refrigerate on arrival. [1]

Shelf Life after Reconstitution, Thawing, or Opening - Ampoule: Discard if not used immediately. Vial: Until outdated, if not contaminated. [1]

Cost of $1.50 - $3.79 per dose [3]

  -----

[1] https://wonder.cdc.gov/wonder/prevguid/p0000075/p0000075.asp

[2] https://www.unicef.org/supply/documents/oral-polio-vaccine-o...

[3] https://www.unicef.org/supply/documents/inactivated-polio-va...

When my partner and I did IVF I got pretty good at giving subcutaneous and intramuscular injections. The medications have to be given at set times every day so there's no way to get them at a doctor's office. I had to mix lyophilized medication and inject it using a hypodermic needle and syringe.

It's not impossible to train lay people to inject most vaccines that I've seen. Does the polio vaccine have to be injected into a specific organ or the bloodstream? Or is it subcutaneous or intramuscular? If the latter this is a solvable problem by organizing aid workers or by forming a small network of competent locals, distributing lyophilized vaccine, training, and having vaccination clinics.

OPV is only applied in developing countries, where setting up an infrastructure with syringes and refrigeration is way harder.

IPV is better in all ways, but OPV still is better than nothing at all, even if it can sometimes mutate back to the wild variant and cause polio... this only occurs however if you are not fully vaccinating the population, as only non-vaccinated children can get infected.

https://polioeradication.org/wp-content/uploads/2018/07/GPEI...

No, IPV is NOT better in all ways. And your link verifies that fact.

Specifically IPV only protects you from serious illness. OPV stops transmission. Therefore where polio is endemic, you need to supply OPV to end transmission. Once polio is no longer endemic, IPV guarantees protection without the additional risks that OPV brings to those around who are immunocompromised or not immunized.

Fair points, I stand corrected.

>> So, let's try to understand this: if we throw a boatload of money onto this problem, is it possible to eradicate polio using that decent, more expensive vaccine?

I think the answer might be - let's spend another boatload of money to develop an even better (oral) vaccine that can be distributed to those areas and not cause cases. It may seem a waste to create a new vaccine when the disease is almost gone, but so what? If Bill Gates can use his fortune to end Polio, I'll forgive him for unleashing Windows on the world ;-) OTOH if it makes a comeback that would mean all the money spent so far was for nothing.

Scientists do not have a theoretical misunderstanding of viruses. But the general public often does.

If you gave everyone IPV, anyone who is not immunocompromised will be protected from severe cases of polio. Yay! But polio can still circulate and be looking for new victims. It is hard to tell how big a problem this is until you stop vaccinating.

When people get OPV, it stops them from being part of polio circulation, but can also START polio circulating. Therefore it is needed to stop transmission, but you don't want it if there is no transmission in the community.

We already eradicated 2 forms of polio. But the question is whether we can realistically eliminate the last.

Not quite. In many of the regions cited it would not be safe to enter and provide the training, let alone the infrastructure for the clinics.

Even if staff receive training, they may not stay on the job long or may not receive refresher training.

Visit rural Africa and you will understand.

I don’t understand how the current strategy can be expected to work. There are two vaccines: IPV and OPV. IPV does not cause outbreaks, but it does not induce sterilizing immunity [0]. So polio (harmless vaccine polio or dangerous polio, vaccine-derived or otherwise) can circulate in IPV-vaccinated populations.

But the US hasn’t administered OPV since 2000 [1]. So polio can circulate in the US without causing symptoms! Anywhere with a sufficient population of people under 23 can be a reservoir of polio.

I don’t understand how the overall strategy can be expected to eradicate polio. Even if the nOPV vaccine were perfect, any reintroduction of polio from any source (wild, old type 2 vaccine-derived, nOPV-derived) could circulate in the US and then be reintroduced elsewhere from here.

I don’t get it. Presumably the US should start administering nOPV just to control its own outbreak.

[0] https://pubmed.ncbi.nlm.nih.gov/22532797/ [1] https://www.cdc.gov/vaccines/vpd/polio/index.html

Never forget:

https://www.newscientist.com/article/2277145-cias-hunt-for-o...

Yeah that "clever trick" has no doubt cost tens of thousands of lives. If not more.

Thats secret services or state interests in general, they have a goal and rest is collateral damage. In some cases its neglible, in some other its massive and borderline genocide. Not that people in general care about it that much, those people dont have US or EU passports to cause much outrage.

I am little bit afraid the best possible outcome would be some lesson for the future, but I dont think its even that. More like a lot of bragging about success part, and thats it. I guess human life in general has completely different value for average HN user like you and me, compared to some military or intelligence high rank.

Can we modify the oral vaccine (virus) to be more resistant to mutation? Specifically, I'm thinking there is a lot of redundancy in the codon table - mapping triplets to amino acids. If we increase the levenshtein distance between the vaccine-virus and the bad one without changing its protein structure it should reduce the likelihood of reverting back in the wild.

We tried that. It reduced the frequency with which it happens, but not as much as we would like.

https://www.science.org/content/article/first-polio-cases-li...

Wow that’s quite a fine at Rotary

Well played.

In all seriousness though, given the money and effort Rotary has put into this cause, this article has certainly given food for thought.

It is, but even if your goal is technically unattainable, I think it's sorta the journey that matters to mix metaphors. Getting the number as low as possible matters and remembering the how scary something we take for granted as an out-of-date problem is good on all kinds of levels. It totally always warmed me up a bit to know that my local Rotarians who where I live anyway are not usually the sweetest types would make this their thing.

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