Misconceptions about the safety and efficacy of vaccinations for preterm infants have led to delays in immunization for these infants. It is important that preterm infants with prolonged hospital stays begin necessary immunizations prior to neonatal intensive care unit (NICU) discharge to allow development of early protection from infectious agents prevalent in the community, especially pertussis. The American Academy of Pediatrics current recommendations can be summarized as follows:
“Preterm infants born at less than 37 weeks gestation and infants of low birthweight (<2500 grams) should, with few exceptions, receive all routinely recommended childhood vaccinations at the same chronologic age as term infants” even if they are still hospitalized. “Gestational age and birthweight are not limiting factors when deciding whether a clinically stable preterm infant is to be immunized.” In addition, “vaccine doses given to term infants should not be reduced or divided when given to preterm or low birth weight infants.”
Table E–1.IMMUNIZATIONS FOR PRETERM INFANTS ||Download (.pdf) Table E–1.IMMUNIZATIONS FOR PRETERM INFANTS
|Age ||Infection Prevented ||Recommended Vaccine |
|Birth ||Hepatitis Ba || |
>2000 g birthweight, medically stable, mom Hep B antigen negative:
Hep B monovalent vaccineb at birth or shortly thereafter
>2000 g birthweight, medically unstable, mom Hep B antigen negative: defer Hep B immunization until stable clinical condition
<2000 g birthweight, ≥30 days of chronologic age: Hep B monovalent vaccine,b dose 1 at 30 days chronologic age, if medically stable
<2000 g birthweight, <30 days chronologic age at hospital discharge, give Hep B monovalent vaccineb at discharge
|1–2 months ||Hepatitis Ba ||Give the second dose of Hep B vaccine at 1–2 months of agec |
|2 monthsd || |
Diphtheria, Pertussis, Tetanus
Haemophilus influenzae type b
Rotavirus vaccine can be given to preterm infants as follows: medically stable, between 6 weeks and <15 weeks, with first dose given at hospital discharge, or after discharge—series should not be started after 15 weeks of agef
|4 months ||All of those listed for 2 months ||All of those listed for 2 months except Hep B: if using monovalent Hep B, no vaccine at 4 months. If using a combination vaccine with Hep B, then acceptable to have baby receive a total of 4 doses of Hep B vaccine |
|6 months || |
All of those listed for 2 months
All of those listed for 2 months, except: if PedvaxHIB or Comvax is administered at 2 and 4 months, a dose at 6 months for Hib not necessary
Inactivated influenza vaccine, 2 doses beginning at 6 months of age, with second dose 1 month later
|Hospital discharge ||RSV ||Appropriately selected preterm infants may benefit from immunoprophylaxis with palivizumab beginning at hospital discharge and then monthly during RSV season. Refer to yearly regional recommendations for guidelines |
Effectiveness of Immunizations
For the majority of premature infants, their protective antibody responses to immunizations are comparable to those seen in term infants. However, studies have shown that preterm infants weighing <2000 g may not respond as well to hepatitis B vaccine given at birth. Therefore, the hepatitis B immunization schedule has been altered for preterm infants or low birthweight <2000 g.
Complications of Immunization
Adverse events have been reported after vaccine administration and historically have led to concern limiting immunization of premature infants. Adverse events may be caused by the vaccine or may occur by chance after immunization. Any event that is considered serious or unexpected and possibly related to the vaccination should be reported. Serious adverse events include anaphylaxis (see Chapter 65), abscess formation, encephalitis, acute flaccid paralysis, fever (>40.5°C), persistent screaming, severe local reactions, and seizures.
Preterm infants are not at higher risk for these types of adverse reactions as compared with term infants. Premature infants generally tolerate immunizations as well as term infants and experience fewer febrile and local reactions to immunizations because of their more immature immune systems. Contraindications to immunizations are the same for all infants and include a significant febrile illness, active seizure disorder or encephalopathy, or any known allergies to the vaccine components (ie, eggs).
An increased incidence of apnea with or without bradycardia after immunization with whole cell DTP was recognized in extremely low birthweight infants <1000 g, but has not been reported with DTaP. Cardiorespiratory events (apnea and bradycardia with desaturations) can be seen in preterm infants given combination DTaP, IPV, HepB, and Hib conjugate vaccines, but are not reported to have a detrimental effect on the clinical course of immunized infants according to the AAP Red Book.
There is little data regarding the immunologic responses of extremely preterm infants receiving steroids for the treatment of bronchopulmonary dysplasia/chronic lung disease (BPD/CLD). Live vaccines should not be administered to babies receiving prednisolone (2 mg/kg/d for more than 1 week or 1 mg/kg/d for more than 1 month) or the equivalent dose of dexamethasone. Live vaccines should not be administered while babies are hospitalized in the NICU.
Premature infants over 6 months but less than 2 years of age with a history of BPD/CLD or reactive airway disease should be considered for vaccination against influenza.
Select premature infants are eligible to receive prophylaxis against the respiratory syncytial virus (RSV) as a monthly injection given during RSV season. Eligibility requirements can change yearly. It is recommended that physicians use local references at the beginning of the RSV season for guidance on dosing.