Higher-Valency Pneumococcal Conjugate Vaccines: An Exploratory Cost-Effectiveness Analysis in US Seniors

Introduction: Use of the 13- valent pneumococcal conjugate vaccine in nonimmunocompromised adults aged =65 years is controversial. Higher-valency conjugate vaccines (15-valent and 20-valent) are under development; their potential cost effectiveness in older adults is unknown, particularly when potential indirect (herd immunity) effects from childhood vaccination are considered. Methods: A Markov model estimated the cost effectiveness of current U.S. recommendations and alternative strategies using currently available and in-development pneumococcal conjugate vaccines in seniors. Separately, strategies using a hypothetical 20-valent vaccine adding the 7 most common disease-causing non-13-valent vaccine serotypes were considered. Sensitivity analyses were performed and alternative scenarios were examined. Data were gathered and the analyses were performed in 2020. Results: In analyses considering only existing and in-development vaccines, sole 20-valent vaccine use cost $172,491/quality-adjusted life year gained compared with current U.S. recommendations under baseline assumptions (equal serotype effectiveness and no childhood vaccination indirect effects). Strategies using 15-valent vaccine were more costly and less effective. When 13-valent/20valent vaccines were assumed ineffective against pneumococcal serotype 3 and 15-valent vaccine was fully effective, 15-valent vaccine cost $237,431/quality-adjusted life year gained. With indirect effects considered, 15-valent or 20-valent vaccine cost >$449,000/quality-adjusted life year gained. When adding hypothetical 20-valent vaccine under baseline assumptions, hypothetical 20-valent vaccine cost $139,348/quality-adjusted life year gained. Conclusions: In-development pneumococcal conjugate vaccines may be economically unreasonable in older adults, regardless of serotype effectiveness assumptions, particularly when considering potential indirect effects from use of those vaccines in children. Adult vaccines containing high-risk serotypes not contained in childhood vaccines may be more promising. Am J Prev Med 2021;61(1):28- 36. (c) 2021 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Automated summary

The use of 13-valent pneumococcal conjugate vaccine in nonimmunocompromised adults aged 65 years and older is controversial. Higher-valency conjugate vaccines (15-valent and 20-valent) are being developed, but their cost effectiveness in older adults remains uncertain, particularly when potential indirect effects from childhood vaccination are taken into consideration. The study analyzed the cost effectiveness of current U.S. recommendations and alternative strategies using existing and in-development pneumococcal conjugate vaccines, as well as a hypothetical 20-valent vaccine. The results suggest that in-development vaccines may not be economically feasible in older adults, especially when considering potential indirect effects from their use in children. Future research may focus on adult vaccines containing high-risk serotypes not included in childhood vaccines.