Due to how cases have been reported and vaccination tracked, data corruption has been horrific. It's better to use ASMR or even CMR. Something like the attached. You'd then want to match the timeline vs population dosages administered.
This would help reduce uncertainty. Moreover, it will help reveal any downstream deleterious non-specific effects of the vaccines overall. Unfortunately, it won't calve them off my type, manufacturer, batch, etc., and we know that some have worse DNSEs than others.