Could Benefits Outweigh Risks of Vaccinating NICU Patients Against Rotavirus?

Researchers found that the benefits of vaccinating infants against rotavirus in neonatal intensive care units may outweigh potential risks.

The findings: Researchers found that transmission of pentavalent rotavirus vaccine (RV5)-strain from vaccinated to unvaccinated hospitalized infants was infrequent and without clinical consequence, in a study conducted at Children's Hospital of Philadelphia. Among vaccinated infants, during the week after receiving a dose of rotavirus vaccine, RV5 was detected in samples collected after patients' first dose (70%), second dose (48%) and third dose (32%). Among unvaccinated patients, 99.3% never tested positive for RV5 strain.

Study results indicated that of 126 patients who received their RV5 vaccine before or at discharge from the NICU, 55% of those patients would have been age-ineligible to start the series if initiated only at discharge.

Why it matters: Rotavirus is highly contagious and causes symptoms such as diarrhea and vomiting that lead to dehydration, which can be especially dangerous for infants and young children. While the rotavirus vaccine is typically the best way to protect against or decrease the severity of an infection, current immunization practices recommend vaccinating eligible infants at the time of discharge from the NICU because some immunized infants shed live vaccine-strain rotavirus in stool for weeks after receipt of the vaccine. Vaccinating at discharge is supposed to reduce the rate and risk of rotavirus transmission among unvaccinated NICU patients.

However, the vaccine series must be initiated before a baby is 15 weeks old, and vaccinating at the time of discharge results in some patients who are most at risk for severe rotavirus complications becoming ineligible to receive the vaccine. Evidence collected from a large cohort of patients at CHOP supports that the benefits of in-NICU vaccination of eligible patients likely outweigh the risks posed by the RV5 strain.

Who conducted the study: Researchers from the Centers for Disease Control and Prevention and CHOP conducted the study, including members from Clinical Futures, a Research Institute Center of Emphasis, first author and clinical research project manager Morgan A. Zalot Hammershaimb, MPH, and co-senior author, Susan Coffin, MD, MPH, who is also the Associate Chief of the Division of Infectious Diseases. Carolyn McGann, MD, an attending neonatologist in the Division of Neonatology at CHOP, also contributed to the study alongside co-senior author Kathleen Gibbs, MD, Medical Director of Quality Improvement and Patient Safety for CHOP's Newborn/Infant Intensive Care Unit (N/IICU).

How they did it: Unlike many NICUs, CHOP's N/IICU routinely administers RV5 vaccines to eligible patients. Researchers conducted a prospective study over the course of one year, during which 1,238 patients were admitted. One hundred sixty-two patients received 226 RV5 doses.

Nurses then collected a total of 3,448 weekly stool samples from 774 patients for viral DNA testing to determine the presence of rotavirus. Among those, 2,252 stool samples came from 686 unvaccinated patients to help investigators determine the rate and incidence of transmission. Geospatial analysis of the NICU itself was also conducted to investigate possible causes of transmission.

Quick thoughts: "These data should support NICUs who want to ensure they provide maximal protection for their patients against an important vaccine-preventable disease, rotavirus," Dr. Coffin said.

Dr. Gibbs added: "While this study was conducted in a level 4 referral NICU, our combination of both single patient rooms as well as open pods supports its generalizability to a variety of NICUs of different layouts and sizes."

What's next: The study results offered additional support to the 2021 revision of the American Academy of Pediatrics' Red Book stating that individual institutions may consider administering rotavirus vaccine at the recommended ages, including in NICUs.

Where the study was published: The study appears in Pediatrics. Also, view a corresponding video abstract. Read more about their study design and clinical implications in this post on the Clinical Futures' Research in Practice Blog.