OBJECTIVES: In Costa Rica, the 13-valent pneumococcal conjugate vaccine (PCV13) and 23-valent pneumococcal polysaccharide vaccine (PPSV23) are available to prevent invasive pneumococcal disease (IPD) such as meningitis, bacteremia, as well as community-acquired pneumococcal pneumonia (CAP) caused by serotypes contained in these vaccines. We aim to estimate these vaccines' budget impact (BI) on Costa Rica's public health system.

METHODS: A BI model was used to estimate the change in expenditure over a three-year time horizon of different vaccination strategies in a population of 500,000 people > 65 years in Costa Rica, assuming that 10 % of the population would be vaccinated annually. The BIs compare PCV13, PCV13+PPSV23, and PPSV23 versus no vaccine. The costs included the direct medical cost of IPD, hospital-treated CAP, outpatient CAP, and complications (hearing loss, neuropsychological deficit, epilepsy, major adverse cardiovascular event) collected from a consultancy with experts (bottom-up method). Vaccine costs were from PAHO tariffs, and vaccine administration cost was $1 per dose. Costs were in USD 2022.

RESULTS: Estimated total cost with no vaccine over three years was $35.5million (m), $35.3m, $37.0m, and $36.5m for PCV13 alone, PCV13+PPSV23, and PPSV23, respectively. Compared with no vaccine, the 1st year of BI with PCV13 was $495,717, the 2^nd year was $432,869, and the 3^rd year was -$188,546. The annual total costs for PCV13+PPSV23 or PPSV23 alone were higher than no vaccine. Overall, PCV13 resulted in the lowest budget impact of all three vaccination strategies over three years.

CONCLUSIONS: Vaccinating adults aged >65 years with PCV13 would result in the lowest healthcare budget impact and could be net cost saving over three years compared with no vaccine, though the costs during the first two years might be higher than no vaccine.