If I remember correctly, the number of vaccinated people who get infected and require hospitalization is quite low.

You remember correctly:

More than 99% of recent deaths were among the unvaccinated, infectious disease expert Dr. Anthony Fauci said earlier this month on NBC's Meet the Press, while Walensky noted on Friday that unvaccinated people accounted for over 97% of hospitalizations.

https://www.npr.org/2021/07/16/1017002907/u-s-covid-deaths-a...

As of April 2021, the CDC "unvaccinated" definition includes people who are thirteen days after their second vaccine, https://www.cms.gov/files/document/qso-20-38-nh.pdf

> Fully vaccinated” refers to a person who is ≥2 weeks following receipt of the second dose in a 2-dose series, or ≥2 weeks following receipt of one dose of a single-dose vaccine. “Unvaccinated” refers to a person who does not fit the definition of “fully vaccinated,” including people whose vaccination status is not known

That is wild. The situation in UK is nowhere near '99% unvaccinated suffer terrible outcome'.

On 20th August, Public Health England published a report that is quite a bit more balanced. From Table 5, pp 22-23, Delta cases:

    overnight inpatient admissions (inclusion#)

    all ages
    unknown                      99
    <21 days post dose 1        260
    ≥21 days post dose 1        689
    ≥14 days post dose 2      2,204
    unvaccinated              4,033

    <50 age group
    ...
    ≥14 days post dose 2        366
    unvaccinated              3,044


    deaths within 28 days of positive specimen date

    all ages
    unknown                      16
    <21 days post dose 1         14
    ≥21 days post dose 1          5
    ≥14 days post dose 2        679
    unvaccinated                390

    <50 age group
    ...
    ≥14 days post dose 2         27
    unvaccinated                 72

For all adults percent fully vaccinated is 75%, whereas for <50, percent one dose vaccinated is somewhere between 60-75%

https://assets.publishing.service.gov.uk/government/uploads/...

https://www.bbc.com/news/health-55274833

This may be explained by Simpson's Paradox. Something similar happened in Israel, if you look at the raw case numbers for the current wave, it looks like the vaccine only has a ~67% efficiency:

https://www.covid-datascience.com/post/israeli-data-how-can-...

The UK and Israel both have very high vaccination rates of older people, and lower fully vaccinated rates of younger people. Someone who is 75 most likely has a much weaker immune system than someone who is 25, to the point where someone who is 75 and fully vaccinated may have a much harder time fighting the virus than someone who is 25 and unvaccinated.

The data from Israel if broken down by under and over 50s, shows the vaccine efficiency is 92% for under 50s and 85% for over 50s. Israel mainly used Pfizer though, where as the UK mainly AstraZeneca, so there could also be differences there.

Of course Simpson's is heavily at play, of course especially when lumping <25s with >75s. Not sure I see how one can get from the (UK) data to statements like 'more than 99% of recent deaths were among the unvaccinated', which seems off by at least an order of magnitude.

The number of people possibly infected by a vaccinated person as an asymptomatic or mild symptomatic carrier and who may require hospitalization is still ambiguous. I will continue to err on the side of caution, tho I have little worry for myself personally.