Timeliness and risk factors associated with delay for pneumococcal conjugate 10-valent routine immunization in Brazilian children.

BACKGROUND

Vaccination coverage is the usual metrics to evaluate the immunization programs performance. For the 10-valent pneumococcal conjugate (PCV10) vaccine, measuring the delay of vaccination is also important, particularly as younger children are at increased risk of disease. Routinely collected administrative data was used to assess the timeliness of PCV10 vaccination, and the factors associated with delay to receive the first and second doses, and the completion of the PCV10 3+1 schedule.

METHODS

A population-based retrospective cohort study was conducted with children born in 2012 in Central Brazil. Children who received the PCV10 first dose in public health services were followed-up until 23months of age. Timeliness of receiving each PCV10 dose at any given age was defined as receiving the dose within 28days grace period from the recommended age by the National Immunization Program. Log-binomial regression models were used to examine risk factors for delays of the first dose and the completion PCV10 3+1 schedule.

RESULTS

In total, 14,282 children were included in the cohort of study. Delayed vaccination occurred in 9.4%, 23.8%, 36.8% and 39.9% children for the first, second, third and the booster doses, respectively. A total of 1912 children (12.8% of the cohort) were not adequately vaccinated at the 6months of life; 1,071 (7%) received the second dose after 6months of age, 784 (5.4%) did not receive the second dose, and 57 (0.4%) received the first dose after six months of life.

CONCLUSION

A considerable delay was found in PCV10 third and booster doses. Almost 2 thousand children had not received the recommended PCV10 doses at 6months of age. Timeliness of vaccination is an issue in Brazil although high vaccination coverages.