Introduction

Infants born prematurely who spend the first months of their lives in the NICU will reach the age of vaccination during their hospitalization. The Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics recommend that medically stable infants begin receiving routine immunizations at the same chronological age, regardless of prematurity, with few exceptions.^1,2 Vaccine response rate is related to postnatal age more so than gestational age.³ Because most maternal antibodies are passed to the fetus after 32 weeks’ gestation, they are missed by infants born prior to 32 weeks. This population may be at increased risk for vaccine-preventable diseases for many reasons including comorbid medical conditions; administration of medications, such as corticosteroids, that may alter their already immature immune function; and disruption of protective barriers, such as skin, due to central lines and other hardware.

Hepatitis B Vaccine

The hepatitis B virus has been targeted for worldwide eradication because of its role in causing liver cancer.¹ A staple in that plan is administration of hepatitis B vaccine at birth for all babies. Part of prenatal testing in the United States includes obtaining hepatitis B surface antigen in the mother. For mothers who are positive, a dose of hepatitis B vaccine should be administered to the baby as soon after birth as possible regardless of weight.^1,2,4 A dose of hepatitis B immune globulin 0.5 mL intramuscularly (IM) should also be administered at the same time but in the opposite leg. Infants less than 2 kilograms (kg) should receive three additional doses of the vaccine beginning no earlier than 1 month of age. In essence, this initial dose does not count in the three-shot series for these babies. By administering both hepatitis B vaccine and the immune globulin to these infants within 24 hours of birth, the effectiveness in preventing hepatitis B transmission is 85 to 95%.⁵

Infants of mothers who are hepatitis B surface antigen negative should also receive their first hepatitis B vaccine at birth with parental consent if they are greater than 2 kg.² Infants who are less than 2 kg at birth should receive the hepatitis B vaccine at 30 days of age if medically stable or prior to discharge, whichever comes first. Approximately 90% of newborns who contract hepatitis B are at risk for developing chronic infection.⁵ By immunizing infants early, pharmacists can ensure that they are protected during this time when they are most vulnerable.

If maternal hepatitis B surface antigen is unknown initially, then hepatitis B vaccine should be administered within 12 hours of birth regardless of weight.²

Despite recommendations for universal screening and immunization, up to 90 cases of perinatally acquired hepatitis B infection are reported to the CDC each year.⁵ Pharmacists can play a role in initiating protocols that ensure (1) all mothers are tested and (2) all babies born to mothers who are hepatitis B surface antigen positive receive appropriate post-exposure prophylaxis.

Two-, Four-, and Six-Month Vaccines

All infant immunization schedules begin at 6 weeks of age⁶; however, depending on the time of administration of the first hepatitis B vaccine, NICU babies may not receive immunizations until 2 months of age. A minimum of 28 days must separate the first and second doses of hepatitis B vaccine.⁴ At 2, 4, and 6 months of age, the following vaccines are currently recommended:

Inactivated polio virus (IPV)

Diphtheria, tetanus, and pertussis (DTaP)

Hepatitis B (HepB)

Haemophilus influenza (Hib)

Pneumococcal conjugate (Prevnar-13)

See Table 15-1.⁶

Combination vaccines such as Pediarix (IPV/DTaP/HepB) and Pentacel (IPV/DTaP/Hib) may be used to reduce the number of injections required to administer these vaccines.

Stay updated, free articles. Join our Telegram channel

Join