The health authorities recommend that you get vaccinated when it is first offered. If you choose not to get vaccinated when the vaccines come to your town or settlement, it is not known when they will eventually be available again. It cannot be guaranteed that you will have the opportunity to get vaccinated at a later date. This is because in some locations the vaccine cannot be stored locally.
Vaccination is offered fewer times in the settlements. This is why it is recommended that you get vaccinated as soon as you are offered the opportunity to do so.