I'm starting to suspect this isn't because the vaccines are inherently particularly good, though. They're incredibly effective against one particular strain of Covid-19, and for a while that was pretty much the only thing in circulation, but as soon as more came along their effectiveness against those started to drop. Viruses less novel than Covid-19 presumably have a lot more genetic diversity, so being incredibly effective at one specific variant with one specific genome would achieve a lot less.

Honestly, I'm seriously starting to doubt whether it's even remotely feasible to achieve herd immunity with the current vaccines - the Delta variant is looking really worrying on that front.

This is factually incorrect. Of the four known COVID strains in broad circulation, the Moderna and Pfizer vaccines have displayed efficacy against all of them.

The Delta variant is more contagious, but has not demonstrated vaccine escape behavior against Pfizer and Moderna [1], and although efficacy was shown to be reduced by mutations in trials, both vaccines still successfully result in complete neutralization in of the virus by antibodies in test titres (in brief: you vaccinate people, then draw their blood and expose the antibodies to virus in vitro and see whether neutralization is effective - it was).

[1] https://www.theguardian.com/world/2021/jun/15/the-covid-delt...

This is a pretty ignorant response. There are many ways to judge a vaccine than its effectiveness. There are also side effects. And its pretty standard for people to get the "Pfizer-flu". That's a pretty major downside to a vaccine. And as well, we don't know the long-term health impacts. There may be heart issues related to taking the vaccine. We have to wait until the data comes in.

> That's a pretty major downside to a vaccine

The Shingrix vaccine is recommended for everyone over 50. It's a two-dose regimen to prevent shingles. If you've ever known anyone who has shingles, you'll rush to get those shots as soon as your doctor recommends it.

Guess what? The side effects can be rough. I know from personal experience: the second dose knocked me down for at least 24 hours. I felt awful and pretty much did nothing but sleep. By the evening of the next day, I was fine.

I also got my Pfizer vaccine shots around the same time, and had nothing worse than a sore arm. Even if someone had told me there was a 100% chance I'd have the same side effects from the COVID-19 vax as I did from Shingrix, I still wouldn't have hesitated. A day or two of feeling terrible versus the known dangers of COVID-19 is an easy choice.

Don't overplay the "major downside" bit.

Which COVID-19 vaccine did you get, and what side effects did you have, if any?

yep... plus issues with astrazeneca, where chances of clotting issues and death might be higher than covid deaths for specific groups (young women mostly). Killing two teenage girls to save a 100 grandmas is a hard math to do.

Do you have a source for those numbers?

I use Google, but there are alternatives. OP is obviously using very round numbers, but given that is not wrong.

Those numbers are wildly optimistic. I would like to see which studies you are quoting so I can review them.

For the Pfizer mRNA vaccine here are the results from studies in Israel.

https://pharmaceutical-journal.com/article/feature/everythin...

It gives a lot of data on chances of symptoms and illness at various periods after the first and second doses from various studies, however the bottom line is that long term the national level studies show that:

“The vaccine also provided 97.2% protection against hospitalisation overall and 97.5% protection against severe and critical hospitalisation.”

These are outstanding results, among the best of any vaccine ever developed, and from studies of large a large and diverse population.

It was 100% effective is a study of 2,000 12-15 year olds. This is important because in countries like Brazil where the death rate is incredibly high, even the small fraction of victims that are children adds up to many hundreds, or even thousands of deaths.