Vaccination coverage and delay in vaccination of infants born in 2017 and 2018 in municipalities in the Southern region of Brazil: National Vaccination Coverage Survey 2020.

To evaluate vaccination coverage and delay in vaccine dose administration in infants in six municipalities in the Southern region of Brazil. National Vaccination Coverage Survey 2020, with infants born alive in 2017 and 2018, carried out from September 2020 to March 2022. Coverage of doses administered, doses administered on time and delay in dose administration were evaluated. For 4681 infants analyzed, coverage for vaccines recommended up to 24 months was 68.0% (95%CI 63.9;71.8%) for doses administered and 3.9% (95%CI 2.7%;5.7%) for doses administered on time. Delay time for the majority of late vaccinations was ≤ 3 months. For some boosters, 25% of vaccine administration was delayed by ≥ 6 months. In addition to tracking vaccine defaulters, strategies are needed to encourage compliance with the vaccination schedule at the recommended ages. Vaccination coverage for the set of vaccines recommended up to 24 months was 68.0% and 3.9% for on-time doses. Delay time for some doses exceeded six months in up to 25% of infants with delayed vaccination. Monitoring vaccine administration at the recommended ages is necessary, with the adoption of strategies that reinforce routine vaccination to prevent vaccination delays and abandonment. Primary care in surveillance and care for infants needs to reinforce actions to ensure timely vaccination. Studies to deepen knowledge of vaccination delay, determinants and strategies for their reduction are necessary.