Actually, they are not. They only advise participants to get tested if they show symptoms. So it's possible that a bunch of people on the vaccine are getting asymptomatic cases.

Where did you get that info? I didn’t read it in the release.

That’s not good though... really could but a kink in establishing herd immunity until everyone is actually vaccinated.

Pfizer released the study design, available at https://pfe-pfizercom-d8-prod.s3.amazonaws.com/2020-09/C4591.... It's a long document, but it's in there.

Thank you!

My wife is in a different vaccine trial. For her they do a test monthly. They also do a blood draw where I would guess they are checking for antibodies, but I don't know. In addition, she reports in every single day with an app for symptom reporting.

That data may be collected in trials, but it isn’t always used for determining the primary outcome(s)

umm this seems non-ideal. I assume people want to be vaccinated against the damages covid causes, neurological, cardiovascular, etc, not just against the symptoms of covid.

a) Those are symptoms too

b) It's likely that it is protecting against those. But hard to specifically prove that it's protecting against each and every symptom. I think the hope is that if you don't develop lung issues, you are unlikely to develop long term damage.

I was just responding to the GP regarding when candidates are tested. Sure they're symptoms. That'd be relevant if they were following the non-placebo group to test for long-term organ damages or other "symptoms" too. The easier way would be to consistently test all candidates for asymptomatic covid which isn't the case here.

Maybe I'm misunderstanding the data here. It seems like we've only directly proven that the vaccine has been effective at reducing the normal symptoms (coughs, fevers) to the point where candidates don't seem to be prompted enough to go get tested anymore. It doesn't directly prove those candidates didn't get covid.

I don't know how you expect these companies to prove their vaccine protects against asymptomatic long-term damage when nobody can prove asymptomatic long-term damage exists in the first place. It's like asking a home security company to prove their system keeps leprechauns out of the house.

COVID is symptomatic, it's a disease. This vaccine is not preventing getting infected, just reduces getting.the disease significantly. I'm more optimistic about Moderna, as this vaccine doesn't prevent me from infecting my parents.

Still, I'll use this vaccine if I can't get Moderna in time. The safety profile looks great.

> This vaccine is not preventing getting infected, just reduces getting.the disease significantly. I'm more optimistic about Moderna, as this vaccine doesn't prevent me from infecting my parents.

What does that mean? Don't both vaccines work exactly the same? Both are mRNA vaccines.

Moderna's trial protocol collects data to evaluate asymptomatic infections. Pfizer's trial protocol does not.

They have different targets. Moderna stops you from getting infected, BioNTech vaccine stops you from getting sick. mRNA is the delivery technology.

They do the same exact thing.

Not really sure why this is downvoted. SARS-CoV-2 is the virus, COVID-19 is the combination of virus and symptoms.

I can't say anything about these vaccines, but there is such a thing as a non-sterilizing immunity, that would prevent you from developing COVID-19 but still be infected and able to spread SARS-CoV-2.

> This vaccine is not preventing getting infected

What does this mean?

As I understand it, all vaccines ever do is provide you with a prepared immune system for when you do get infected.