Numerous studies have been presented to ACIP over the last few years covering asymptomatic infections, symptomatic infections, and hospitalizations. From the 2021 meeting covering Pfizer-BioNTech, there were 5, [1] 17 [2], and 13 [3] of these studies, respectively. There are similar sets for Moderna [4]. From what I've seen of the ACIP meetings, those are the results they focused on the most.
I don't have much knowledge of medical research but I don't see how this could possibly be "completely absent". Would love to hear more about what's missing from these and the dozens of other studies which have been done since.
1: https://www.cdc.gov/vaccines/acip/recs/grade/covid-19-pfizer...
2: https://www.cdc.gov/vaccines/acip/recs/grade/covid-19-pfizer...
3: https://www.cdc.gov/vaccines/acip/recs/grade/covid-19-pfizer...
4: https://www.cdc.gov/vaccines/acip/recs/grade/covid-19-pfizer...