I think most frequently the society restricts the freewilled acts _upon_ another person. I'm not sure I agree that going out in public is an act upon another person. They are free to touch door knobs or not. They are free to associate or not in public places.
Obviously I shouldnt be allowed to sneeze on someone (how this is defined is unclear) or to enter their private space w/o permission...
This is a bit analogous to the right to photograph/film in public.
I can choose to drive at 100mph in the wrong lane of traffic. This is not impinging on anyone else's free will. They are free to not use that lane, to drive around me, or to join me in going 100mph.
Photography in public is not a public health or safety issue and does not overwhelm hospitals with its effects.
The libertarian view point is that personal freedoms should not be limited, except in narrowest of scopes.
Examples of US policies that limit personal freedoms for the good of society without a direct infraction on someone else include: export controls, gun laws, mandatory auto insurance, income tax, state laws on vaccinations.
Because some of us see our friends, family, and neighbors as more than a set of genes to pass on to the next generation.
And if those friends, family, and neighbors are clogging up a strained medical system that could even cause harm to us when we require such services for our own well being.
Because humans are more than their immune systems - I'd argue the Salk made society far stronger than a society requiring polio immunity as a precondition to live
Unfortunately all humans are born with weak immune systems, and sadly babies aren't fully vaccinated until they are ~2 years old. We protect them, because they eventually become our society. That pesky "future generations" concept.
You see, our immune system is built up over time with exposure to viruses, and inoculations. Then as we age, as our health decreases, our immune system gets worse again.
Personally, as I make my way through middle age, I hope that when I do reach my golden years I'm met with a little bit more compassion than "who cares about you, you're old and useless."
Funny enough, I know someone who has an auto immune system disorder, and recently found out this person is a lead figure in setting up Covid-19 response systems for major healthcare systems in the US.
Obviously I shouldnt be allowed to sneeze on someone (how this is defined is unclear) or to enter their private space w/o permission...
This is a bit analogous to the right to photograph/film in public.