Does a correlation exist between delayed vaccination and a decreased vaccine confidence?

Area of Science:

• Public Health
• Epidemiology
• Vaccinology

Background:

• Vaccination delays increase the risk of vaccine-preventable disease outbreaks.
• Parental vaccine confidence and sociodemographic factors are potential contributors to delayed immunization schedules.
• The Vaccine Confidence Index (VCI) measures confidence in vaccines using a 5-point Likert scale.

Purpose of the Study:

• To identify sociodemographic factors associated with delayed measles, mumps, and rubella (MMR) vaccine administration (first and second doses).
• To compare parental vaccine confidence between children with delayed versus on-time MMR vaccination schedules.

Main Methods:

• Study conducted in the Region of Murcia, Spain, analyzing 2019-2020 (first dose) and 2016-2017 (second dose) MMR vaccine cohorts.
• Participants categorized into: vaccinated on time, slightly delayed, moderately delayed, and highly delayed.
• Data collected via online and telephone questionnaires administered to parents.

Main Results:

• For the MMR first dose, delays were associated with birth order and child's intellectual/motor delay, parental education, primary vaccine information source, and social network usage.
• For the MMR second dose, delays linked to child's motor/intellectual delay and caregiving responsibilities for siblings.
• Vaccine Confidence Index significantly decreased with increasing delay for the first dose, but not for the second dose.

Conclusions:

• Sociodemographic factors significantly influence delays in MMR vaccine administration, particularly for the first dose.
• Parental vaccine confidence is associated with delays in the MMR first dose schedule.
• Understanding these factors is crucial for improving vaccination coverage and preventing outbreaks.