ATLANTA - Administering the first dose of the hepatitis B vaccine (HepB) at birth is associated with increased likelihood of completion of the three dose series, according to Tasneem Malik, MPH, National Immunization Program, Centers for Disease Control and Prevention (CDC).
Malik and colleagues conducted a survey of hospitals in early August 1999, several weeks after a joint statement was issued by the American Academy of Pediatrics (AAP) and the Public Health Service recommending the removal of thimerosal from childhood vaccines and cessation of administration of thimerosal-containing HepB vaccines to low-risk infants younger than 6 months of age. They reviewed surveys completed by 977 hospitals representing 25% of the United States birth cohort. They presented the research at the 10th International Symposium on Viral Hepatitis and Liver Disease.
Seventy-nine percent, or 773 of 977 hospitals, indicated they were aware of the joint statement. Hospitals with .500 births per year were more likely to be aware of the joint statement than those with >500 births per year.
Prior to publication of the joint statement, 88% (679 of 773) had a policy or routine practice for vaccinating all or some of their newborns with hepatitis B vaccine at birth. After publication of the joint statement, 79% (604 of 773) instituted a change in the policy or practice of universally administering HepB vaccine to newborns of hepatitis B surface antigen (HBsAg) negative mothers.
In August 1999, one month after the joint statement was issued, a vaccine that does not contain thimerosal as a preservative became available (Recombivax-HB, Merck). In March 2000, the Food and Drug Administration approved the newly reformulated preservative-free Engerix-B (SmithKline Beecham) pediatric/adolescent (10 mg/0.5mL) HepB vaccine.
"We've done studies that have looked at what the hospitals are doing now that hepatitis B vaccine that does not contain thimerosal as a preservative is available," said Malik. "We're finding that many hospitals have not reinstated the birth dose for infants born to HBsAg negative women."
A related study, also presented at the 10th International Symposium on Viral Hepatitis and Liver Disease, found that prior to the concern about thimerosal, 57% of newborns were born in hospitals that gave thimerosal-containing HepB vaccine; 35% were born in hospitals that vaccinated selectively and 8% were born in hospitals that did not vaccinate.
Of the 41 of 47 hospitals surveyed that vaccinated with HepB, nine did not plan to resume HepB vaccination with a thimerosal-free vaccine and seven were undecided.
The researchers concluded that information about HepB changes reached most hospitals quickly, but data indicates that fewer neonates will be vaccinated with HepB now compared with before the thimerosal concern.
"Reintroduction or re-initiation of birth-dose practices after vaccines that do not contain thimerosal as a preservative became available has been slow," said Hussain Yusuf, MD, epidemiologist at the CDC. "We hope that ultimately it will go back to even higher levels of birth-dose administration than we had previously seen."
There are two recommended HepB vaccination schedules. One schedule requires the first dose be given soon after birth and before discharge at the hospital; the second dose at 1 to 2 months; and the third dose between 6 and 18 months. The alternate schedule requires the first dose at 1 to 2 months; the second dose at 4 months; and the third dose at 6 to 18 months.
Both are acceptable schedules with similar outcomes in terms of immunity or antibody response, according to Yusuf. The schedule using the first dose soon after birth is the preferred schedule according to the ACIP and the AAP.
Said Yusuf, "Along with increasing the likelihood of hepatitis B vaccine series completion, advantages of giving the first dose at birth, before the infant is discharged from the hospital, include that you're starting the vaccine at first contact with the child, avoiding a missed opportunity to vaccinate. You can convey the importance of the vaccine early on to the parents. In addition, we don't want any child to fall through the cracks of programs to prevent perinatal transmission of hepatitis B, but in case one does, this is a safety net."
According to Malik, the safety net concept applies to infants born to HBsAg positive mothers, to mothers whose HBsAg status is not known when they deliver in the hospital, or to mothers who are HBsAg negative but may have behavioral risk factors for hepatitis B infection which could present a problem for the child, the family and the mother in the future.
"We know of infants that have fallen through the cracks where kids born to HBsAg positive women did not get timely immunoprophylaxis," said Malik. "Administering the first dose of the vaccine to these infants at birth would give them a high level of protection against hepatitis B virus infection. The other issue is that prenatal care providers need to screen all pregnant women for HBsAg during every pregnancy. The state or local hepatitis B prevention program needs to be notified of every positive test result so that these children can receive appropriate follow-up. Hospitals need to ensure that every infant born to a HBsAg mother receives hepatitis B vaccine and hepatitis B immune globulin within 12 hours of birth, as recommended."
For more information:
- Malik T, Petersen T, Yusuf H, Brink E. Impact of recent recommendations for postponing routine administration of hepatitis B vaccine to newborns. Abstract B065, p. B36.
- Brayden R, Pearson K, Sigafoos J, Berman S. Effect of thimerosal recommendations on hospital hepatitis B vaccination policies. Abstract B068, p. B38.
- Both presented at the 10th International Symposium on Viral Hepatitis and Liver Disease. April 9-13, 2000. Atlanta.
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