"benefit of a few" meaning "allow those few that were adversely affected to sue for damages" which would have the follow-on effect of hampering vaccine development
Vaccines are like 99.999% safe.. but we do give them to more than 100k people per year, so some people do suffer some unfortunate side effects including and up to seizures and brain damage. We've decided as a society that the benefits of widespread vaccination outweigh the legal rights of those harmed by their administration, so we've legislated away the ability to sue vaccine manufacturers for good-faith efforts at developing and administering vaccines.
I will gladly line up for the Covid vaccine and I'll definitely be vaccinating my children, but there is a remote risk of harm.