EXPLORATORY COST-EFFECTIVENESS ANALYSIS OF IN-DEVELOPMENT AND HYPOTHETICAL HIGHER-VALENCY PNEUMOCOCCAL CONJUGATE VACCINES IN OLDER ADULTS: BARKING UP THE WRONG TREE?
Higher-valency pneumococcal conjugate vaccines (PCV) are under development; their potential cost-effectiveness in older adults (≥65 years) is unknown.
A Markov model estimated the cost-effectiveness of current US recommendations and sole pneumococcal polysaccharide vaccine (PPSV23) use compared to: in-development PCV15 and PCV20, and a hypothetical vaccine (HypoPCV20) adding the 7 commonest non-PCV13 serotypes in older adults (all with/without PPSV23). Sensitivity analyses and alternative scenarios were examined.
In analyses considering only existing and in-development vaccines, sole PCV20 use cost $176,500 per quality-adjusted life-year (QALY) gained compared to current US recommendations, while dual PCV20/PPSV23 use cost $4,050,000/QALY when equal serotype effectiveness and no childhood vaccination indirect effects on added serotypes were assumed. PCV15 strategies were dominated. When PCV13/PCV20 were assumed ineffective against serotype 3 and PCV15 was fully effective, PCV15 cost $209,000/QALY and PCV15/PPSV23 cost $1,403,000/QALY. Adding childhood vaccination indirect effects or alternative serotype effectiveness assumptions decreased PCV15/PCV20 cost-effectiveness. When HypoPCV20 was considered, HypoPCV20 cost $152,700/QALY gained, and HypoPCV20/PPSV23 cost $2,480,000/QALY; other strategies were dominated.
In exploratory analyses, PCV15/PCV20 may not be economically reasonable in older adults, regardless of serotype effectiveness assumptions, particularly when potential indirect effects were considered. Adult vaccines containing higher-risk serotypes not contained in childhood vaccines may be more promising.