I cannot reply to your other questions in replies to me because your submissions are flagged. In one of your replies you ask, "Other comments state that anyone

I cannot reply to your other questions in replies to me because your submissions are flagged. In one of your replies you ask, "Other comments state that anyone can carry the virus, even vaccinated people though..." Vaccinated people will fight off the virus and reproduce a lot fewer copies before their immune system knocks it out. This is effectively near zero compared to a vaccinated person. As for game theory, every person is making a choice (or his parents are). One can be a "free rider" (https://en.wikipedia.org/wiki/Herd_immunity#Free_riding https://en.wikipedia.org/wiki/Herd_immunity#Free_riding). If there are too many free riders in the population, any infection will ripple through it into those who are not vaccinated. It's totally fine for a small number of people to be unvaccinated. When they start using Twitter and it becomes a large enough number, the population crosses the tipping point, infecting the unvaccinated who benefited from the herd immunity.