I am not entirely sure why you are getting downvoted. It says right in the study > Vaccine-expanded T cells were durable, persisting up to 2 years despite post

I am not entirely sure why you are getting downvoted. It says right in the study > Vaccine-expanded T cells were durable, persisting up to 2 years despite post-vaccination mFOLFIRINOX treatment So yes, that seems to suggest you may have to keep going back every couple years for more boosters.