Don't know about actual numbers but NFID says this. Sounds reasonable to me.How many years of clinical trials were done on the Shingles Vax before it came to market? I believe the correct answer is 3. I don't recall it being politicized or mandated?
Its tried and true with years of successful use. Not much to worry about with it.
Final question: How many shingles vaxxed people still get shingles? Millions?