[Vaccine-associated poliomyelitis: safety of the oral poliovirus vaccine, Brazil, 2013-2023Poliomielitis asociada a poliovirus derivados de la vacuna: seguridad de la vacuna oral contra la poliomielitis en Brasil, 2013-2023].

OBJECTIVE

To quantify the occurrence of vaccine-associated paralytic poliomyelitis (VAPP) cases in Brazil from January 2013 to May 2023.

METHODS

A descriptive study was conducted on VAPP cases reported as events supposedly attributable to vaccination or immunization (ESAVI) following oral poliovirus vaccine (OPV) administration. VAPP cases were defined as acute flaccid paralysis (AFP) with isolation of vaccine-derived poliovirus in stool samples and persistence of motor deficits after 60 days.

RESULTS

A total of 200 suspected cases were identified, with two confirmed as VAPP (<1 case per 10 million doses administered) based on the isolation of the vaccine virus. Risk factors associated with VAPP included incomplete vaccination schedules, malnutrition, and/or immunodeficiency.

CONCLUSIONS

VAPP occurrence was rare and aligned with expected values. Continued surveillance of ESAVI and suspected VAPP cases is essential to support poliomyelitis eradication efforts and ensure vaccine safety.