What are the recommendations for vaccination of preterm infants?

Preterm infants should be vaccinated at the same chronological age and according to the same schedule as full-term infants, regardless of birth weight, with the exception of the birth dose of hepatitis B vaccine. Infants weighing less than 2 kg (4.4 lb) whose mothers’ HBsAg status is either positive or unknown should receive HBIG (hepatitis B immune globulin) and hepatitis B vaccine within 12 hours of birth. This dose of hepatitis B vaccine should not be counted as a valid first dose in the series, and it should be repeated at age 1 month. If the preterm infant’s mother’s HBsAg status is negative, the infant’s first dose of hepatitis B vaccine should be withheld until the infant is chronologically 1 month of age or is ready to be discharged from the hospital, whichever occurs first.

CDC now classifies HepB as a shared clinical decision-making vaccine for infants born to test-negative mothers; however, the American Academy of Pediatrics continues to recommend routine infant immunization to protect newborns as soon as feasible from unrecognized exposures and lifelong chronic hepatitis B virus infection. For more information on timing, see the Vaccination of Preterm Infants subsection of the Special Situations section of CDC’s “General Best Practices for Immunization”, available at www.cdc.gov/vaccines/hcp/imz-best-practices/special-situations.html#cdc_report_pub_study_section_4-vaccination-of-preterm-infants.