As long as the long term effects aren't even well understood because a) there has not even been a long term of a post-pandemic world yet, there's not even been a mid-term and b) research is in full swing, there will be any number of medical results and outcomes that may or may not happen to a particular group of subjects. Unless you're OK with being conciously part of a given subject group and/or want to be the first that gets it in this grand experiment, taking less risk still means taking less risk and/or delaying disease and possibly changing negative outcomes into positive ones.