“…Thus, the FDA has approved its administration in healthy adults ≥ 50 years of age, with contraindications including anaphylaxis to gelatin or neomycin, immunosuppression, immunodeficiency and pregnancy. The SPS demonstrated efficacy for 4 years after vaccination, while subsequent studies (52,53) indicated efficacy for 8 years (54). Currently, CDC does not recommend booster doses of zoster vaccine, but may in the future.…”