Very neat and practically clear design which is very friendly with data collector, especially in wide tick box.
In my opinion, I would remove weight in collecting demographic data, which I assume that it cannot be associated with the study.
Physical examination is well categorized including a detail section to provide its abnormal codes.
I am not sure what collected sample type means. If there is ID in the specimen or lab result, we can also add it.
More detail information about administrated vaccine can be added such as site of administration, route of administration, lot no, which would help in tracing back in finding out in manufacturing fault and adverse events.