Anything that the state would 'suggest' or attempt to force onto citizens, Anarchism is generally opposed to. Hopefully that covers that.
Think about it like this: If you throw 100 random individuals into a random area and told them simply to "survive", you would then see Anarchism begin to develop. Certain people would take on construction. Some would take on defense. Depending on the background and skills of the individual, that will then determine there 'place' in society, informally and naturally. You will also have those who are more skilled with medicine, healing, etc.
^That group of people will be the ones to determine such things as 'immunizations'.. at least at the beginning. When sickness and disease becomes more of a problem, the group mentioned above will likely be the ones to take initiative and look into immunizations and whatnot. If society NEEDS it, society will work for it.
Things like you mentioned are, as far as I know, state-controlled (like CDC). The state is generally viewed as the 'caretaker' and people rely on it for medicine, research, etc. Now in a stateless society, PEOPLE will have to decide what's important and what's not and when disease and vaccinations becomes a concern, an organization will more than likely be formed to address such issues.
^Just my opinion.
