Perhaps but there is no parallel between the polio and the COVID vaccine. The former reduced the incidence of polio by more than 99% while the latter, well it does not.
Possibly, but the vaccines have prevented many orders of magnitude more cases: "Since 2000, more than 10 billion doses of OPV have been administered to nearly 3 billion children worldwide. As a result, more than 13 million cases of polio have been prevented, and the disease has been reduced by more than 99%. During that time, 24 circulating vaccine-derived poliovirus (cVDPV) outbreaks occurred in 21 countries, resulting in fewer than 760 VDPV cases."[1]
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.
> OPV produces excellent immunity in the intestine, the primary site of wild poliovirus entry, which helps prevent infection with wild virus in areas where the virus is endemic.
It seems like the polio vaccine actually prevents infection which is not the case for the COVID “vaccine” which is purely therapeutical.
"Unfortunately, IPV costs considerably more than OPV per dose ($3-5 vs $0.12 on the subsidized world market). Because the WHO and most countries have plans to continue vaccination for at least 10 years after eradication, there will continue to be a market for the vaccine. Because of the high cost of the IPV, efforts are underway to derive improved and less expensive IPV vaccines."
"One hundred twenty-six low- and middle Income countries will start to use IPV, which is injected, in a single dose, in addition to the oral polio vaccine (OPV). OPV will gradually be phased out, based on certain epidemiologic triggers.
The previous price was a major barrier to making this shift. The shift is needed because, for eradication to occur, the polio virus needs to be gone from people, labs, sewage, etc. – i.e. the places in which vaccine-derived polio virus can survive, mutate and cause disease. IPV is ‘inactivated’, and does not carry risk of polio infection to people who are not vaccinated."
> seems like the polio vaccine actually prevents infection
OPV (“o” as in oral) sterilises. IPV (“i” as in inactivated) doesn’t. IPV doesn’t spread vaccine-derived poliovirus, so it’s the more widely-used one. (It comes down to whether the virus is neutralised in the gut or the blood.)
The polio case in Brooklyn was an unvaccinated man getting a vaccine-derived infection from the sterilising OPV [1][2].
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.
The rollout of COVID-19 vaccines was far faster than Salk's polio vaccine. It was not used in lower income countries for quite a while, really until OPV came along to really get going. The vaccine was made by multiple manufacturers in the US, including what is now Pfizer.
You're arguing semantics when you knew what I meant. Polio vaccines have all but eliminated the virus in the wild (33 cases worldwide as of 2018). It's more effective in every way shape or form when compared to Covid-19 vaccines, which makes the comparison invalid.
Right, and if OPV is what they're focused on, the thing is: Nobody is attempting a live attenuated coronavirus vaccine. So the OPV reversion situation is completely irrelevant to this exemption.
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.
I'm not sure what exactly GP is referencing, but maybe it's the rare cases when the weakened virus in OPV mutates and someone excretes infectious, vaccine-derived poliovirus. I still don't see how that's the fault of the vaccine providers, since it's due to mutation and not a mistake in production of the vaccine, and OPV is a reasonable thing to use and certainly better than doing nothing.
> 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.
What if we have IPV first then OPV as a booster, would that give sterilizing immunity with less risk?
In the case of Polio there is actually Vaccine derived poliovirus VDPV[2], the person getting the vaccine is immune, however he can transmit it to un-vaccinated people for the OPV version which was administered in the U.S. till 2000
OPV is known to cause paralytic poliomyelitis(polio) in 3 cases per million doses given [3]
Okay, I should probably have been a bit clearer about that. Polio eradication efforts everywhere in the world, including the US, were based around the oral polio vaccine due to its apparent benefits in stopping vaccinated people from spreading polio. This was discontinued in the developed world, including the USA, a couple of decades ago (edit: and replaced with the inactivated polio vaccine - I though this was clear enough from the context...) after polio was eliminated there and the risk of spread from other countries was considered low enough. Entire age groups have never been vaccinated using the OPV. And of course it doesn't matter how well protected the population as a whole is if there's a subcommunity of people who regularly interact with each other who aren;t...
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