Constrained Optimization for Pneumococcal Vaccination in Brazil.

Abstract

OBJECTIVES\nTo identify the most cost-efficient combination of pneumococcal vaccines in infants and aging adults for a 10-year period in Brazil.\n\n\nMETHODS\nConstrained optimization (CO) prioritized 9 pneumococcal vaccine regimens according to their gain in quality-adjusted life-years (QALYs) and their related costs over a prespecified time horizon with defined constraints for 2 age groups, infants and aging adults. The analysis starts from the current universal infant vaccination of pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV), 2 primary and 1 booster dose at 2, 4, and 12 months, respectively. Key constraints are the fixed annual vaccine budget increase and the relative return on investment (ROIR) per regimen, which must be > 1, the reference intervention being the current vaccination strategy in infants and the most cost-efficient one in aging adults.\n\n\nRESULTS\nThe CO analysis including all the constraints indicates that over 10 years the maximum extra health gain is 126 194 QALYs for an extra budget of $974 million Brazilian reals (ROIR\xa0= 1.15). Results could be improved with a higher proportion of the at-risk population in aging adults, less herd effect, and better QALY scores.\n\n\nCONCLUSION\nThe study shows that with 4 constraints on budget, time horizon, vaccine coverage, and cost efficiency, a CO analysis could identify the most cost-efficient overall pneumococcal vaccination strategy for Brazil, allowing for limited vaccine budget increase while obtaining appropriate health gain.