Look at it this way: How can a person that is not vaccinated "harm" people that are vaccinated? How are they putting those people at risk? If the vaccine actually works, then the vaccinated people are safe from any infection, aren't they? So, the only person "at risk" is the person that chose not to vaccinate. This comes down to personal choice, there is no question of "the greater good" or social risk.
Some vaccine advocates will then claim that unvaccinated people could be host to "mutations" that threaten herd immunity. The problem is that there is no evidence to support this argument. The vast majority of viruses tend to mutate into less deadly strains, not more deadly, unless they are deliberately designed or engineered to mutate in an unnatural manner. There is simply no basis for the position that an unvaccinated person puts vaccinated people in danger.
If a virus is able to mutate into a vastly different and more deadly strain that can attack vaccinated persons then the vaccine was never useful to begin with, and forced vaccinations are pointless.
