Some amount of vaccine caused polio has for a long time been a problem. The point being made here is that this was a newer polio vaccine which attempted to avoid the risk.
It's "vaccine designed to minimise vaccine-caused polio still causes a small number of cases"
The second take away is, it's still better than earlier versions of the vaccine.
So it could have been "reduced breakout vaccine-caused polio cases in new vaccine deployed in Africa"
"A problem" is a bit of an understatement... at this point it's basically caused the global polio eradication effort to fail. Wild type 2 poliovirus no longer exists anywhere in the world, and all infections with it over the last couple of decades are vaccine-derived. The original plan was that everywhere would switch to a bivalent oral vaccine without the type 2 virus, any remaining vaccine-derived outbreaks could be mopped up with monovalent vaccine, and then it would finally be eradicated for real. This failed - there were widespread outbreaks and targetted vaccination just caused the number of outbreaks to increase. The new oral vaccine was the fallback plan and the fact that this is already happening with it is not a great sign.
It's impossible to be 100% certain, but there's no animal reservoirs for polio that have ever been known to exist and it hasn't been seen in humans for a couple of decades now - if it was still in existence we'd probably know about it by know, given how infectious polio is. All of the recent outbreaks are either type 1 poliovirus (mostly in Pakistan and Afghanistan) or have been linked to the vaccine via genetic testing.
Eh, the oral polio vaccine is old, cheap, and kind of predates the rise of modern big pharma. Disease eradication is just a hard problem in general. The only human infectious disease that's been eradicated - smallpox - was a particularly easy target for various unique reasons, including the existence of a live vaccine that was incredible effective despite being so wildly different from the actual disease-causing virus that it couldn't easily cause serious disease in humans itself.
Recurring revenue vs one time purchase. Not saying this is the case, but we see the obvious attraction to recurring revenue from most software companies.
The injectable polio vaccine does not stop the transmission. It only make the virus not attack the nervous system, so you don't get paralysis. This is good, but it's impossible to erradícate polio with it.
Yes, the COVID vaccines is what i am referring to. Well, i don't remember the specifics, but i do remember after that, some other countries started slowly changing route as well.
Actually, a medicine, a vaccine causing the disease it is trying to prevent, is such a strange concept. Imagine hiring someone to keep backup of a database. After some work, installing some programs, and moving some files around, you end up some days later, with a corrupted database and no backup. That person at the start, assures and reassures that everything will go correctly, your database will be safe forever etc. How happy you would be knowing that the person most probably responsible for the corrupted disk, is the expert disk engineer?
We stopped doing the oral in the US due to the risks of vaccine-associated paralytic poliomyelitis (VAPP) and circulating vaccine-derived polioviruses (cVDPVs).
This is more or less why antivaxxers have at least some rational ground to stand on.
And this isn't the first time a Polio vaccine has caused the disease [0]:
> In April 1955 more than 200,000 children in five Western and
> mid-Western USA states received a polio vaccine in which the
> process of inactivating the live virus proved to be defective.
> Within days there were reports of paralysis and within a month
> the first mass vaccination programme against polio had to be
> abandoned. Subsequent investigations revealed that the vaccine,
> manufactured by the California-based family firm of Cutter
> Laboratories, had caused 40,000 cases of polio, leaving 200
> children with varying degrees of paralysis and killing 10.
Right, I believe the messaging around vaccines exacerbates the issue too. Especially with mrna covid-19 vaccines, the condescending tone used by the CDC and media outlets while implying no safety risks throw people off. If you don't upfront say there's some risk and explain it it gives room for antivaxxer propaganda that builds on those doubts. IMHO, the media campaigns for the mRNA vaccines did the opposite of that.
All existing vaccines have risk, however they're at least a factor off 100 safer. I find if you explain this, and why they're still a good choice people respond well. Especially if you give the history of people / scientists working on them. There was a study posted on HN a while back that showed mothers who were given an explanation months before birth had a higher vaccination uptake rate.
It is the word "vaccine" that somehow triggers scary narratives in these crowds; recently, in denmark a very common antibiotic was found that it contained a bunch of highly antibiotic resistant bacteria, causing disease to a few people, and having unpredictable consequences for a lot more in the future (as it seems that these antibiotic resistant bacteria have colonised them and can potentially trigger disease any point). If this was a vaccine it would have triggered a lot of different narratives than just being in some news.
> All existing vaccines have risk, however they're at least a factor off 100 safer
mRNA vaccines are qualitatively different, though, not just slightly further on a sliding scale. The only risks AFAIK are from the delivery mechanism and the immune response; the payload itself is, well, mRNA molecules, which can't produce pathogens at all.
While you correctly identify the cause, the rates of myocarditis and pericarditis younger people receiving the vaccine are far higher than with other vaccines we give. See https://bmjopen.bmj.com/content/12/5/e059223 for verification.
> The only risks AFAIK are from the delivery mechanism and the immune response
Which is a risk. The mRNA vaccines AFAICT are somewhere around a factor 100x safer than covid-19 for the general population. I hope research gets published that get that number more accurate.
Also, it seems risks like myocarditis stem from the lack of common best practices around the delivery mechanism like dosing and hopefully could be reduced.
https://www.verywellhealth.com/what-is-a-live-virus-vaccine-... is a recent article with a partial list of common vaccines that are live. They tend to be more effective than alternative vaccines. And, unless you are immunocompromised, they are very unlikely to make you sick.
What makes the polio vaccine more complicated is that it is given orally, multiplies, passes through your body, and comes out in your feces. Which gives it a route by which it can infect people other than the person who received the vaccine. The same does not happen with injected live vaccines.
There is an inactivated polio vaccine that is given with a needle. That is used by the USA and most advanced countries. But it is more expensive, is harder to deliver (you need multiple shots on a schedule), and is less effective. It does protect the recipient against becoming paralyzed, but does not stop you from getting a mild stomach infection and passing it on in your feces where you can spread it to others. Therefore only the oral vaccination can halt an active community outbreak.
However the fact that the oral vaccine can also START a community outbreak means that we have to be careful where we use it.
You're only going to see this in the case of live attenuated vaccines. They can mutate and become virulent (since they were mutated to attenuate them in the first place).
You're not going to see that with mRNA vaccines, you're not going to see that with the adenovirus-vectored vaccines. You're not going to see that with inactivated virus vaccines (like most influenza[*] or CoronaVac or the Sinopharm COVID vaccines).
Live attenuated virus vaccines are one of the oldest vaccine methods and have been around since the 19th century. They're created by culturing the virus serially in artificial media and isolating a strain which is less virulent. Very brute force laboratory methods that only require the ability to culture the virus and an animal model of virulence with decent correspondence to human virulence.
One thing to remember is that we're dealing with a medical triage situation and its better to cause a very small amount of disease in order to eradicate most of it. People get hung up on the fact that medical science is a human activity that doesn't have perfectly flawless outcomes like in Star Trek, while the natural diseases are orders of magnitude worse.
[*] Except the Flumist nasal spray is live attenuated. Still with influenza that isn't likely a big deal. I would be willing to wager a bit that this technique is still being used there because the influenza virus is very good at getting past the nasal mucosa and we don't know how to engineer particles that do that very well (still no nasal COVID vaccine).
I don't think it's easy to summarize in a useful manner because it basically comes down to how a specific vaccine works.
For example, subunit vaccines like the whooping cough vaccine use a portion/fragment of the infectious agent, which means it is literally impossible for such a vaccine to cause the illness it is supposed to work on since there is none of that agent in the vaccine in the first place.
Attenuated vaccines, such as some polio vaccines and the MMR vaccine, include a weakened version of the infectious agent. These types of vaccines can result in a full-blown infection, especially in immunocompromised people.
So in short, the risk of a full-blown infection from a vaccine is going to depend on the type of vaccine, and I suspect there's variation within each type as well.
Depending on how the vaccine works this is normal because the mechanism is infecting you with a low dose or weakened version of the virus, in simple terms.
>If a layman said this I would have dismissed them as a conspiracy nut
Should make you think about how most of us approach the problem, right? How often are we told a truth and despite not knowing anything about the topic we dismiss it as nonsense? If you're an expert in some niche field you'll know it happens all the time.
You have to activate the immune system somehow. Sometimes presenting deactivated viruses or parts of viruses - viral capsids or nucleic acids - is not enough. Sometimes you can't find a good adjuvant.
It depends on the vaccine. Some vaccines use a "weakened" form of the pathogen to trigger immunity response without causing actual disease, but sometimes, especially in cases of weaker immune systems, this can cause actual disease. This is not the case with most modern vaccines as they use different methods (and certainly not of covid19 vaccines), and certainly not what antivaxxers usually talk about (if anything, covid19-antivaxxers for example were proponents of getting _real_ infection instead of vaccine).
What's your source for that? She did supposedly fall ill and go into a coma from heart arrhythmia, caused by a form of bacterial pneumonia. Which admittedly sounds suspicious. But I don't see anything linking this directly to a vaccine.
I've read in a few reputable seeming places that polio was on the decline before the vaccine was introduced [1].
This chart [2] (if accurate) is pretty eye opening.
I've also read that the diagnostic criteria for polio was changed roughly in conjunction with the release of the vaccine, which resulted in a significant decline in case counts. This article [3] discusses that and the headline claims to debunk it, but the content didn't do a very good job to me, it kind of did the opposite when I read it, so I'm still left curious.
I've also read that the primary contributing factor to the decline (and recent rise) in polio is sanitary conditions. Most of these arguments come from biased anti-vaccine publications, so I'm skeptical but that doesn't necessarily invalidate the points.
I've discussed this with older relatives who swear to me, pointedly, that the polio vaccine was a godsend, and that polio was a common horror prior to the vaccine.
Note I am looking for expert feedback on these points, I would appreciate it if folks avoided just piling on me and calling me an anti-vaxxer (I'm not, I have to receive regular life saving vaccines due to a medical condition). I don't have any "sacred cows" though, and I'd love more information from experts out there that can explain/refute these points, because once I parse through all the propaganda and anecdotes I'm left very confused about the actual efficacy of the polio vaccine.
Are there controlled studies that compare infection rates in populations that account for confounding variables like sanitation?
> This chart [2] (if accurate) is pretty eye opening.
It might be important to note that that chart specifically tracks deaths, not incidence.
At least according to the US CDC [0], paralytic polio (which I think most people think of when they see the word "polio") is generally the type that kills, usually due to paralysis of respiratory muscles and related symptoms.
Given all that, it turns out that the first iron lung that saw widespread use was developed in... 1928! (And other versions had been developed before that) [1] And iron lungs are fantastic for preventing death due to paralysis of respiratory muscles, as the lung does the muscles' job. This could either be until the patient recovers or permanent.
So in short, it's entirely possible the death rate fell because new tech allowed doctors to get better at keeping patients alive, rather than reducing the incidence, as the vaccines were generally intended to do.
> I've also read that the primary contributing factor to the decline (and recent rise) in polio is sanitary conditions.
At least according to the CDC, it's a mixed bag:
> In the immediate prevaccine era, during the first half of the 20th century, improved sanitation resulted in less frequent exposure and increased the age of primary infection, resulting in large epidemics with high numbers of deaths.
Can't really say much on the other claims or the paper, since that'd take way more expertise and/or time than I currently have.
Also, polio has waves. 95% of the persons that get the virus doesn't get paralysis, so in a big outbreak most people get infected but only a small part get paralysis.
If there are no infections going on for a long time, there are many people that can be infected and if there are some initial cases you can get a wave. After the wave almost everyone got infected and will not be infected again so any outbreak dies. But after some years there are too many young people that can be infected and you get another big wave.
It's "vaccine designed to minimise vaccine-caused polio still causes a small number of cases"
The second take away is, it's still better than earlier versions of the vaccine.
So it could have been "reduced breakout vaccine-caused polio cases in new vaccine deployed in Africa"