Adherence to National Rotavirus Vaccine Standards in Preterm Infants

Background: Rotavirus remains the leading cause of severe gastroenteritis in early childhood. Despite preterm infants’ risk of severe illness and highest potential benefit from vaccination, most neonatal intensive care units (NICUs) are reluctant to administer the live-attenuated rotavirus vaccine. Additionally, outpatient providers may be hesitant to administer the vaccine or may lack knowledge regarding vaccine eligibility in former premature infants. We assessed outpatient adherence to rotavirus vaccine administration in eligible preterm infants born at an overseas U.S. Department of Defense (DoD) military hospital.

Methods: In a retrospective chart review, we evaluated infants who were born at ≤36+6 weeks gestational age (GA) and admitted to the NICU at the U.S. Naval Hospital in Okinawa, Japan between January 2010 and December 2018, who qualified to receive the rotavirus vaccine upon NICU discharge ( <15 weeks chronologic age without contraindications to vaccination). Adherence was assessed by how many eligible infants received at least one dose of a rotavirus vaccine series (either RV1 or RV5), as well as how many were fully vaccinated. Chi-square analysis was used to evaluate categorical demographic factors between rotavirus vaccine adherence groups (SPSS, Armonk, NY).

Results: We identified 331 neonates who met study inclusion criteria (57% male, median birth weight 2280g, IQR 1731-2660g; median GA 34.5 weeks, IQR 32.3-36.1 weeks). Those born in the lowest quartiles for weight ( <1731g, p <0.0001) and GA ( <32.4 weeks, p = 0.001) were the least likely to receive any dose of rotavirus vaccine (Figure 1). Infants were more likely to complete a full vaccination course of RV1 (2 doses) as compared to RV5 (3 doses) (p < 0.001). Infants with bronchopulmonary dysplasia (BPD) had lower odds of receiving even a single dose of rotavirus vaccine compared to those without BPD (37% versus 86%, Odds Ratio 10.98).

Conclusion: Our findings demonstrate that a large proportion of premature infants who qualify for the rotavirus vaccine upon NICU discharge are not receiving standards of vaccine care. Alarmingly, the most vulnerable premature neonates are at highest risk to be incompletely vaccinated. Our data also suggest improved vaccine adherence using a 2-dose (RV1) rather than 3-dose (RV5) regimen.