From what I read, Pfizer's effectiveness against the delta variant is not as good. 1 dose is 35% effective and 2 doses is 80-85% effective. Research shows that protection lasts for 6-12 months and perhaps even longer. I also think boosters will be available in the fall (a 3rd dose rather than having to get another 2 doses). I don't know if J&J's vaccine follows the same trend but I assume Moderna's will. I'm hopeful it can be given at the same time as a flu shot and an annual flu/covid shot will become a thing.
Regarding J&J I have a cousin who went to Disney with wife and 2 little kids. Parents are both J&J vaxxed. They wore masks most of the time but when they returned had light cold symptoms so didn't think much of it. Their parents (grandma) who is fully Pfizered later had a bad fever and a little trouble breathing so they all got tested and all had covid (don't know details like if it was a particular strain). No hospitalizations, though, which is the purpose of the vaccine but you can still catch it and spread it.
Well, no vaccine is perfect.
But I will say this: the Israel study that says the effectiveness is way lower is totally different. It's measuring a different thing.
95% efficacy, which is about what Pfizer scored in clinical trials, literally means that in the trial, 95% of positives times two came from the placebo group. Or, in other words, if the infections between the placebo and vaccine group is 50/50, efficacy is 0%. If it's 100/0, efficacy is 100%. That gives you a good idea of what 95% means.
The 64% Israel study is a real-world observation which says that, basically, if you are
exposed to covid, and vaccinated, you have a 64% chance of not contracting it at all. But if you do contract it, the likelihood of it being any worse than a mild illness is probably closer to that 95% efficacy, maybe even higher.
In the US, between 98-99.9% of hospitalizations are unvaccinated, so that's your real-world effectiveness against serious illness which is what really matters.
Again, in Israel, that number is lower, but I wouldn't be alarmed. Israel has vaccinated between 85-90% of its adults. Your breakthrough number is always going to be a function of how many vaccinations you have. For example, in New York, about 74% of adults have had a vaccine dose and 1.5% of hospitalizations are breakthrough. If your community is 100% vaccinated, 100% of hospitalizations are breakthrough, which goes to show you how fast that number can jump as you continue to vaccinate people.
In any community with large swaths of both vaccinated and unvaccinated people, observed hospitalizations have been almost all unvaccinted.
