My doctor advised me to get the Shingrix vaccine with a 97% effective rate instead of Zoster with a 52% effective rate. But if Zoster also prevents dementia and

My doctor advised me to get the Shingrix vaccine with a 97% effective rate instead of Zoster with a 52% effective rate. But if Zoster also prevents dementia and Shingrix doesn't, what's the expectation-maximizing choice?