@sda Its a bit of a misnomer that every combination must be tested before we can rule out harm. In statistics if there was a harmful reaction that was significant between mixing vaccines we would see it in the data from the populous who generally take many overlaping vaccines. The only way we wouldnt notice it is if the effects are so rare that it would be lost as statistical noise. If thats the case it is a non issue anyway since its so rare it effects few people.
@freemo
Well, the WHO doesn't seem to agree with you:
"... we're really only in the
beginning of the era of large datas, sets, where hopefully
you could START to uh, kind of harmonize the databases for multiple studies, uh, and there's actually, uh an initiative under way, uh, Helen, there, uh, uh, may want to comment on it to try get more national vaccine safety database linked together so could start to answer these type of questions that you just raised."[about antigen/adjuvant cross reactions]
- Dr. Robert Chen, Brighton Collaboration (at the Global Vaccine Saftety Summit Geneva 2019/12/3)