This is still fluid - they are continously running studies on this matter. The latest I heard (at least with the pfiz. vac) is that they now think they will last a year. THe other thing that is showing up is that even if you do get sick you are not likely to have long haul issues that a lot of people are suffering but the press mostly ignores.They're saying protection afforded by the vaccine can start to wane after 6 months. If they don't offer a booster, the new variants which are more transmissable can start the spread of covid again, perhaps even to those who were vaccinated.