Moderna made sure that enough old people were included in their trials, even if they lost some time with it.
Pfitzer/BioNTech proved itself by vaccinating old people in Israel, so they clearly have enough data.
Preprint data on hospital admissions seems pretty encouraging for AZD-1222: https://www.bmj.com/content/372/bmj.n523
I'll look at the details, as I have to advise my parents about which vaccine to accept, which is a very difficult decision for me.
Right now they don't trust the Chinese/Russian vaccines, only vaccines approved by the EU, and I also prefer them to wait a few more months in their apartments.
The problem is that once they accept a vaccine, they can't get another type, as only one type of vaccine is allowed per person because of the current vaccine shortage in the world.
There is no reason that response to a vaccine would fall off a cliff above a certain numerical age – the human body just doesn’t work like that. Yes, as people get older their immune responses to vaccines may weaken – but this will be unpredictable in a large group, and likely dependent on far more factors than just chronological age.
If by chance the study hadn’t recruited anybody who was 51 years old, would you have felt uncomfortable extrapolating responses from 50 and 52-year-olds?
I bought them big screen TV, new furniture and elliptic machine so they can spend their time in the apartment while still working out.