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Comment by OscarCunningham | Hacker News Reader

> Pfizer has said people with a history of severe adverse allergic reactions to vaccines or the candidate’s ingredients were excluded from their late stage trials, which is reflected in the MHRA’s emergency approval protocol.

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Smells a little bit like what some of us (developers) occasionally do when under pressure. As in, trying to save some crucial time in a rush, by focusing on testing just the things that were specifically worked on, instead of running it through the entire test suite (or QA dept) before deploying. If something comes up, user feedback will certainly bubble through quickly enough and can be worked on. Which, to be perfectly frank, often does work out just fine.

I'm pretty certain this has nothing to do with pressure.

The risks profile is very different, and for the same reason my trials aren't run on pregnant women. It hardly makes sense (and would be immoral) to include people in a clinical trail who you know are more likely to get adverse affects (up to death) from the drug/vaccine.

Especially for vaccines you know there will be certain subgroups that can't be vaccinated anyway, and because of herd immunity that doesn't matter too much.

Why let those subgroups participate in the first vaccinations though? If they were clearly aware of this, why go ahead in one of the most-watched "deployments" (in my life-time), and invite the potential risk (and it's a huge risk) in only after it's gone "live" with the real population? I mean, if I knew those subgroups would be problematic, I sure as hell would make sure the first week of those vaccinations would go as smooth as possible (with all the media and the rest of humanity carefully watching), and give it to people I am most certain will be fine with it. Everything else, the trials should've caught, or should catch in the near future? Why play the risk on day one?!

While they haven't said yet, it's fairly clear this was an error; either the people with a history of allergies ignored the warnings (every vaccine I've had as an adult has come with allergy warnings) or the warnings weren't given (which would be bad and must be fixed).

> which is reflected in the MHRA’s emergency approval protocol

Makes me think this is an acknowledged limitation and a closer metaphor would be removing some use cases and cutting scope.

I'm not sure I follow why this is news and a changed in protocol if it was known since the approval

This is entirely normal for drug development. AIUI they also didn't test on pregnant people. Given that the aim here is to produce herd immunity, rather than sterilising immunity in 100% of the population, this should all broadly be fine.

Sure, yet, I wonder why this seems to trickle out the day AFTER the first run, when, if it's true what you say (and I have no idea, so you certainly know more about it) they would have been able to avoid this entire report / potential fiasco (think of the anti-vaxxers) by announcing it a bit more boldly beforehand, no? Why let that bit of negative information overshadow the second day?

It's more or less standard. _Any_ new drug is highly likely to exclude certain classes of people. This is particularly the case with vaccines where the risks of excluding a small number of people are generally low, as you're relying on herd immunity anyway.

I'm not sure if this was talked about before, but the fact that (like basically every vaccine ever) it won't initially be available to pregnant women was certainly talked about ahead of time. This isn't a fiasco; it's normal.

I think you miss the point entirely. The broader public's perception of the drug is instrumental to its adoption. If the public are led to believe that the medicine is unsafe, the result will be a reduced level of herd immunity as fewer people will take the vaccine.

Medical institutions (CDC, BMJ, Public Health England), the Government, and the broader media (newspapers, TV stations, companies like Facebook) are responsible for encouraging safe and efficacious use of medicine for the good of society, but they can't do that when the narrative is co-opted by anti-vaxxers, the right, and other shameless opportunists.

Nope. You learn nothing by testing on people with known allergies to the ingredients.

That's a much smaller group than the people who have just been advised not to take it though, and I assume that people in that group would already have been advised not to take it. We don't know what allergies the affected people had AFAIK, but the advice goes far beyond people with a history of severe reactions to vaccines/its ingredients:

> “Any person with a history of a significant allergic reaction to a vaccine, medicine or food (such as previous history of anaphylactoid reaction or those who have been advised to carry an adrenaline autoinjector) should not receive the Pfizer BioNtech vaccine,” it said.

I've never had a reaction to vaccines, I'm unaware of having a reaction to any medicine, so from what Pfizer said I could have been in the trial. But I'd be excluded by this new advice because I carry an epi-pen for a food allergy.

I wouldn't read too much into that warning, at least in terms of overall safety. The fact is, they're releasing these vaccines on a broad scale much faster, and with less safety testing completed, than usual. So there's plenty of things that we normally wouldn't know yet at this stage of development; in this case just leads to authorities being extra cautious, because this is an experiment. It's just that with other vaccines the general public would never become aware of issues like that, because the vaccines wouldn't have been released so early to so many people.

FWIW, looks like the HPV vaccine also had problems with occasional severe allergic reactions: https://www.reuters.com/article/us-vaccine-reaction-idUSN314...

That article is from 2008, so I don't know if that issue has been fixed or not. Regardless, it obviously wasn't a deal breaker, as Gardasil is still being used.

Could we get to herd immunity by not immunizing those people who are part of groups excluded from the trials?

Quite likely - I would expect "severe" allergies to be less than 1% of the population.

I think most vaccines right now have not been proven to have sterilizing immunity, so ppl who have gotten the vaccine can still transmit it to others who haven't been vaccinated. That's in the 1 or 2 week widow after getting infected themselves.

Even if it doesn't produce sterilizing immunity it will reduce the spread by stopping the virus from causing coughing and sneezing. So it's possible that it will allow reaching herd immunity anyway.

That's how normal vaccines for things like measles work. Not everyone can take them, or they have other issues, so they depend on the rest of us to do our part for herd immunity.

Yes. Almost no vaccines can be given to _everyone_, and the portion of the population with severe allergies of the epipen-carrying-around variety is fairly small.

Yes this is news, so clearly there has been some mismatch in expectations.

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