Preterm infants are vaccinated at a lower rate than their peers despite being at high risk for infections, according to a new study.
The Academy and Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) recommend vaccinating preterm infants according to the regular schedule with few exceptions.
Researchers set out to see if these guidelines were being followed by looking at health records from just over 10,000 infants born in 2008-’13 in Washington state. They focused on rates of receiving the combined seven-vaccine series that includes diphtheria-tetanus-pertussis, poliovirus, measles-mumps-rubella (MMR), Haemophilus influenzae type b, hepatitis B, varicella and pneumococcal conjugate. Results are reported in “Early Childhood Vaccination Status of Preterm Infants,” (Hofstetter AM, et al. Pediatrics. Aug. 7, 2019, https://doi.org/10.1542/peds.2018-3520).
The study found about 19% were born preterm, at less than 37 weeks’ gestation. Among those infants, 47.5% had received the recommended vaccines at 19 months compared to 54% of term/postterm infants. MMR and varicella rates were similar between the groups, but term/postterm infants were more likely to receive all other vaccines.
Rates of vaccination at 19 months were highest among infants who were Asian, English-speaking, had private insurance and those with higher birth weight.
At 36 months, just under 64% of preterm infants had completed the recommended vaccine series compared to about 71% of term/postterm infants.
Authors also looked at several vaccines outside the series and found influenza vaccination rates were similar among preterm and term/postterm infants. However, when preterm infants were separated into early (23-33 weeks) or late (34-36 weeks), the early preterm group had better flu vaccination rates than the late preterm or term/postterm groups.
Rotavirus vaccination, which is recommended at or after hospital discharge, followed the same trend as the combination series, with lower rates among preterm infants.
“These findings are worrisome given the increasing prevalence of preterm births and the fact that preterm infants are particularly susceptible to vaccine preventable diseases such as Streptococcus pneumoniae, pertussis, rotavirus, and influenza,” authors wrote.
They said the low rates of vaccination among preterm infants may be due to parents or even clinicians believing it is unsafe for a child who may already have health issues. Some also may be focusing on other health issues instead of vaccination during clinic visits or may not be aware of AAP and ACIP recommendations to vaccinate preterm infants on schedule.
“Future work is needed,” authors said, “to inform the design and implementation of interventions aiming to improve timely vaccination coverage of these high-risk infants.”