Several of the people are in their 20's and were very healthy, so I don't think good health and youth is a guarantee of anything. Are you talking about people who were infected in 2020, or 2021? The majority of the people I know who were hit the hardest had it in early 2020 (pre-vaccination), along with a few who had issues with Delta (post-vaccination). No one I know who was infected since Omicron took over has had issues, whether vaccinated or unvaccinated.