INTRODUCTION The Cuban national program for childhood immunizations began in 1962 and has included a surveillance system for monitoring adverse events following immunization since 1999. The expected rate of adverse events following childhood immunization in Cuba is 50 per 100,000 vaccine doses administered. In 2017, Pinar del Río Province reported higher-than-expected rates of adverse events, which motivated this study on their frequency and types.

OBJECTIVE Characterize adverse events following immunization reported in children in Pinar del Río Province in 2017.

METHODS We examined reports of adverse events following immunization in children from 2 months through 14 years of age in Pinar del Río Province, Cuba, from January 1, 2017 through December 31, 2017. We found 487 adverse events that met the criteria established by the national surveillance system. Information was obtained from epidemiological surveys of adverse events following immunization in Pinar del Río Province municipalities. Recorded were age, municipality, signs and symptoms, vaccine type, number of doses, anatomical site and route of vaccine administration, and the institution where the child was vaccinated. We estimated proportions for intensity and frequency related to vaccination, and calculated rates for 100,000 vaccine doses administered. We then compared the rates of observed adverse events with those of expected events.

RESULTS The overall rate of adverse events was 305.6 per 100,000 doses administered. Highest rates were reported in children aged <1 year (580.9 per 100,000 doses administered); in Guane Municipality (610 per 100,000 doses), for the pentavalent (DTwP-HB-Hib) vaccine (1567.7 per 100,000 doses), and in applications to the anterolateral quadrant of the thigh (772.5 per 100,000 doses). Symptoms classified as moderate, common, and general occurred more often, with fever being the most frequent. Severe induration, hypotonic and hyporesponsive episodes, persistent crying and rashes were observed more frequently than expected.

CONCLUSIONS The rate of adverse events following childhood immunization is similar to that reported in other provinces and elsewhere in the world. Of all childhood vaccines, the pentavalent vaccine is the most reactogenic. The absence of serious adverse events demonstrates the safety of childhood immunization in Cuba.

KEYWORDS Immunization programs, vaccination, surveillance system, adverse events, Cuba