
Why smallpox is no more, but polio and other diseases persist - yarapavan
https://www.quantamagazine.org/why-smallpox-is-no-more-but-polio-and-other-diseases-persist-20191203/
======
basicplus2
<the laboratory-weakened virus used in the oral polio vaccine can very rapidly
regain its strength if it starts spreading on its own.

After a child is vaccinated with live polio virus, the virus replicates inside
the child's intestine and eventually is excreted.

In places with poor sanitation, fecal matter can enter the drinking water
supply and the virus is able to start spreading from person to person.

"We discovered there's only a few [mutations] that have to happen and they
happen rather quickly in the first month or two post-vaccination," Andino
says.

"As the virus starts circulating in the community, it acquires further
mutations that make it basically indistinguishable from the wild-type virus.

It's polio in terms of virulence and in terms of how the virus spreads."

In June, the World Health Organization reported 15 cases of children paralyzed
in Syria by vaccine-derived forms of polio.

These cases come on top of two other vaccine-derived polio cases earlier this
year in Syria and four in the Democratic Republic of the Congo.>

[https://www.npr.org/sections/goatsandsoda/2017/06/28/5344030...](https://www.npr.org/sections/goatsandsoda/2017/06/28/534403083/mutant-
strains-of-polio-vaccine-now-cause-more-paralysis-than-wild-polio)

------
intuitionist
Wild-type polio could very well be gone by now if the CIA hadn’t burned
Western doctors’ goodwill in Pakistan by using fake polio vaccines to take DNA
from children suspected to be related to Osama bin Laden.

This isn’t close to the most evil thing the CIA has done, but it makes me the
most unreasonably angry.

~~~
Twixes
What the hell. This sounds comically villainous. On the other hand we _are_
talking about the CIA here. Got a link?

~~~
kick
The CIA have crafted a wonderful brand: with their actions, they've created a
(truthful) universal public image that they'd stoop to the southern tip of
Hell to get whatever they want, completely numbing the public to any possible
action. If the CIA had a good reputation, hearing something like "They
undermined public faith in vaccines, leading to multiple modern-day problems
and epidemics" would lead to skepticism, and then riots.

Instead, we all know the substance of the agency's actions, and of the
character of its men. As a result, we're mildly surprised when we hear this,
and don't feel it's a substantial deviation from the status quo.

------
3fe9a03ccd14ca5
Here’s a more interesting dilemma, one which I could hardly believe once I
heard it:

> _More Polio Cases Now Caused by Vaccine Than by Wild Virus_

If that’s true, at what point do we _stop_ vaccinating for it?

1\. [https://www.nytimes.com/aponline/2019/11/25/health/ap-af-
med...](https://www.nytimes.com/aponline/2019/11/25/health/ap-af-med-africa-
polio.html)

2\.
[https://www.npr.org/sections/goatsandsoda/2017/06/28/5344030...](https://www.npr.org/sections/goatsandsoda/2017/06/28/534403083/mutant-
strains-of-polio-vaccine-now-cause-more-paralysis-than-wild-polio)

~~~
tyingq
To be clear, it's the cheap, oral, live virus polio vaccine that's causing the
problem.

They don't use that in the US, at all, and we don't have the issue.

We don't need to stop polio vaccination...we need to find a reasonable way to
replace the low budget version.

~~~
akamaka
The live vaccine is not simply a “low budget version”, it’s more effective.

~~~
tyingq
It is not.

~~~
Fomite
There's a number of reasons the live polio vaccine is preferred in developing
countries. The biggest is that the OPV vaccine, as the name suggests, is
_oral_. You don't need needles, which means it's easier to mass administer,
you don't have to deal with sharps, etc. I think people vastly underestimate
the logistical difficulties of delivering vaccines, especially injectables
that require a cold chain like IPV.

It also sheds, which is good if you're struggling with vaccine coverage.
Whether this is a downside or not is a highly dynamic question - as we get
closer, the side effects become a bigger deal, but part of the _reason_
they're a big deal is because WT polio is so heavily suppressed.

------
Liquidity
Small pox is still available in highly secure laboratories of Both US and
Russia. Also, FDA approves small pox vaccine. [https://www.fda.gov/news-
events/press-announcements/fda-appr...](https://www.fda.gov/news-events/press-
announcements/fda-approves-first-live-non-replicating-vaccine-prevent-
smallpox-and-monkeypox)

[https://www.cdc.gov/smallpox/vaccine-basics/who-gets-
vaccina...](https://www.cdc.gov/smallpox/vaccine-basics/who-gets-
vaccination.html)

------
vo2maxer
Several articles in the news including the one in Quanta [1,2,3] appear to
have caused some misunderstanding. What is clear so far is that “circulating
vaccine-derived polioviruses (cVDPVs) can emerge in settings with low
population immunity...,” therefore, “all countries must maintain high
population immunity.” [4] It was found that “compared with January 2017–June
2018, the number of reported cVDPV outbreaks more than tripled, from nine to
29,” in the most recent survey. [4] As a result, the Global Polio Eradication
Initiative” is planning future use of a novel type 2 OPV, stabilized to
decrease the likelihood of reversion to neurovirulence.” One of the most
significant barriers to polio eradication is “reaching every child – including
inconsistent campaign quality, insecurity, conflict, massive mobile
populations, and, in some instances, parental refusal to the vaccine.”[5]

It is false to say that somehow cVDPVs had been kept a secret or their
importance downplayed. [6] There are critical reasons to remain vigilant of
any adverse consequences but keep in mind that every year “hundreds of
thousands of cases due to wild polio virus are prevented. Well over 10 million
cases have been averted since large-scale administration of OPV began 20 years
ago.” [7]

[1] [https://www.quantamagazine.org/why-smallpox-is-no-more-
but-p...](https://www.quantamagazine.org/why-smallpox-is-no-more-but-polio-
and-other-diseases-persist-20191203/)

[2] [https://www.nytimes.com/aponline/2019/11/25/health/ap-af-
med...](https://www.nytimes.com/aponline/2019/11/25/health/ap-af-med-africa-
polio.html)

[3] [https://www.washingtonpost.com/world/africa/more-polio-
cases...](https://www.washingtonpost.com/world/africa/more-polio-cases-now-
caused-by-vaccine-than-by-wild-
virus/2019/11/25/1a4d087e-0f76-11ea-924c-b34d09bbc948_story.html)

[4]
[https://www.cdc.gov/mmwr/volumes/68/wr/mm6845a4.htm](https://www.cdc.gov/mmwr/volumes/68/wr/mm6845a4.htm)

[5] [http://polioeradication.org/news-post/global-leaders-
pledge-...](http://polioeradication.org/news-post/global-leaders-pledge-
us2-6-billion-to-eradicate-polio-at-the-reaching-the-last-mile-forum-in-abu-
dhabi/)

[6]
[https://www.ncbi.nlm.nih.gov/books/NBK236293/](https://www.ncbi.nlm.nih.gov/books/NBK236293/)

[7]
[https://www.who.int/features/qa/64/en/](https://www.who.int/features/qa/64/en/)

