Effectiveness of pharmacist-delivered vaccination recommendations for herpes zoster: a systematic review.

INTRODUCTION: Herpes zoster (HZ) remains an important cause of morbidity among older adults despite the availability of effective vaccines. Recommendations from healthcare professionals are among the strongest determinants of adult vaccination uptake, and community pharmacists are increasingly involved in vaccination recommendations. OBJECTIVES: To systematically review and critically appraise the evidence on the effectiveness of pharmacist-delivered recommendation strategies in increasing confirmed HZ vaccination uptake and recombinant zoster vaccine (RZV) series completion. PATIENTS AND METHODS: PubMed, Embase, and the Cochrane Library were searched from database inception to October 14, 2025. Studies evaluating pharmacist-delivered recommendation interventions aimed at increasing HZ vaccination were included if they reported quantitative outcomes for confirmed vaccination uptake or RZV series completion. Data on study characteristics, interventions, and vaccination outcomes were extracted. Risk of bias was assessed using RoB 2 and ROBINS-I. RESULTS: Nine studies met the eligibility criteria for the primary synthesis of confirmed vaccination outcomes. Eight evaluated ZVL (Zostavax), whereas only one specifically assessed RZV (Shingrix) series completion. Seven studies were conducted in the United States and used predominantly non-randomized designs. Settings ranged from single community pharmacies to networks of 159 pharmacies. Positive effects on confirmed HZ vaccination uptake or RZV series completion were reported in five studies. The strongest evidence came from a cluster randomized controlled trial involving 16 pharmacies, in which automated telephone recommendations increased vaccination rates from 0.72 to 2.60% (OR 3.69; 95% CI 2.64-5.15). Additional positive findings were observed for personalized outreach and pharmacist telephone follow-up aimed at improving RZV series completion. Three studies reported no improvement or decreased HZ vaccination rates. The overall certainty of evidence was limited by methodological weaknesses: six of eight non-randomized studies were rated as having serious risk of bias, and only one randomized trial was available. CONCLUSION: Pharmacist-delivered recommendation strategies may improve HZ vaccination uptake and RZV series completion, particularly when implemented through proactive patient outreach. However, the current evidence base remains limited by the predominance of non-randomized studies and substantial risk of bias. Well-designed randomized and quasi-experimental studies are needed to determine the independent effectiveness of pharmacist-delivered vaccination recommendations.