Objectives: This study aims to demonstrate the costs related to Adverse Events Post Vaccination (AEPV) of diphtheria, tetanus, whole-cell pertussis [DTwP] / hepatitis B [HB]/ Haemophilus influenzae type b [Hib] plus inactivated polio vaccine [IPV], and oral polio vaccine [OPV] (current scenario) versus the introduction of a fully liquid, hexavalent, acellular diphtheria, tetanus, and acellular pertussis [DTaP]-IPV/HB/Hib vaccine (alternative scenario) in the Brazilian public, private and social perspectives.

Methods: An economic model based on a decision tree was developed to demonstrate costs related to AEPV and productivity loss in Brazil. The probabilities were extracted from a published systematic literature review, and the data are specific for each dose (D) (3 doses + booster). We considered the full birth cohort in 2020, 2.9Mi infants, and all costs parameters were extracted from public databases and published data in 2020. Regarding the social perspective, the productivity loss of caregivers was considered only at D3 and D4 due to the maternity leave period in Brazil. The time horizon was one year.

Results: Switching from the current scenario to the alternative may result in savings of 13.4 Mi BRL and 78.8 Mi BRL to the public and private markets, respectively. The main reduction was found to be related to medical appointments to manage the AEPV, with a decrease of almost 60%. Furthermore, a reduction of 13.2 Mi BRL in transportation costs, 0.9 Mi BR in out-of-pocket medications and 8.9 Mi BRL in the productivity loss at the social perspective was also indicated.

Conclusion: The alternative scenario may help to avoid significant costs related to AE management and result in savings in this aspect for health systems and social perspectives. In addition, this may optimize resource allocation in Brazil, simplify vaccination schedule and increase acceptance of acellular vaccines for patients, parents thanks to more favorable tolerability.