Yes, morality has relativity aspects. Concerning the trolley problem, you have the choice between how many people are killed.
But with Covid-19 I never kill anyone. I force nobody to interact with me.
Everybody knows that there's a virus out there and everybody has to decide for himself if he/she wants to get outside and meet other people. If vaxxed or not, I do not kill anyone, even if I have Covid-19 and someone gets it from me.
That would be a distortion of self-responsibility.