BACKGROUND/OBJECTIVES: PCV13 is used in routine infant immunization across all regions of Spain. PCV13 has reduced incidence of invasive pneumococcal disease (IPD) caused by important serotypes, such as 19A, which caused over 20% of invasive disease in children 0-4 years of age in Spain and rapidly emerged during PCV7 use. Our objective is to evaluate health and economic implications of potential disease emergence of non-vaccine types (NVT) following a switch to a lower-valent vaccine (PCV10) in Spain.
METHODS: A decision-analytic model was developed to estimate public health and economic impact of switching infant vaccination from PCV13 to PCV10 across Spain. Historical pneumococcal disease surveillance data were used to estimate disease trends by serotype and to forecast disease emergence and/or reduction for infants (direct effects) and older age groups (indirect effects). For each vaccination program, health outcomes (cases of IPD, pneumonia, and acute otitis media) and costs were estimated. Epidemiologic and cost data were derived from the MBDS and eOblikue databases, respectively, and serotype surveillance was generalized to all of Spain from Instituto de Salud Carlos III.
RESULTS: In the base case analysis, assuming a 2-year lag before disease re-emergence of serotypes not covered by PCV10 ; continued use of PCV13 prevented 170,000 more cases of pneumococcal disease and 1,800 more deaths than if Spain switched to PCV10 over a 10-year period. Despite a higher vaccine cost, PCV13 remains cost-effective compared to PCV10 across several scenarios.
CONCLUSION: Due to factors such as increases in NVT, continued use of PCV13 in Spain would provide a greater public health benefit compared to PCV10. It is important for policy makers to consider disease emergence when considering modifications to vaccination strategies.
