Evaluation of Coverage Rates of 3 Pediatric Vaccines (Measles-Mumps-Rubella, Hexavalent, and Varicella) in a Southern Italian Province (2016-2022): Effect of the Pandemic and Interregional Comparisons.

BACKGROUND Vaccination is one of the most effective tools available to protect against infectious diseases. In Italy, Law no. 119/2017 expanded the list of mandatory vaccinations to 10: against poliomyelitis, diphtheria, tetanus, hepatitis B, pertussis, Haemophilus influenzae type b (hexavalent vaccine), measles-mumps-rubella (MMR), and varicella (chickenpox). The present study focuses exclusively on 3 of them: MMR, hexavalent, and varicella. The emergence of the COVID-19 pandemic led to a significant reorganization of the healthcare organization. The aim of this study was to assess the potential effect of the COVID-19 pandemic on mandatory vaccination coverage. MATERIAL AND METHODS A retrospective analysis was conducted on official vaccination data from the local health authority of Salerno. Coverage rates were compared across pre-pandemic and pandemic years and were contextualized within regional and national trends. RESULTS Hexavalent coverage remained consistently high (>94%) throughout the period, with only minor declines during the pandemic. The MMR vaccine showed a progressive increase from 87.75% in 2016 to over 93% in 2021, with a slight decrease in 2022. The largest increase was observed for varicella, which went from 67.26% to over 91% in 2021-2022. The results highlight an overall stable or growing trend, without persistent declines due to the pandemic. Overall, the resilience of vaccination services has allowed coverage to remain close to regional and national objectives. CONCLUSIONS Pediatric vaccination coverage remained high even during the pandemic, showing the resilience of the local vaccination system. The effective organization allows for maintaining high levels of immunization even in crisis conditions.