That is a conjecture not a fact.

Anecdotally, from the small group of unvaccinated people I know... those of us who eat meat  daily and get regular sunshine, caught covid once and it barely felt like a cold.

Yet my vaccinated, boosted & sun and meat phobic friends and colleagues have had covid many times, and EVERY TIME they were bedridden for days!

I knew three fit middle aged people who have "died suddenly" and one fit person who got turbo cancer leaving a young family behind. Tragic.

Open your eyes.