The 36th National Immunization Conference of CDC

Wednesday, May 1, 2002 - 11:00 AM
653

Reductions in hepatitis B (HB) vaccine coverage for infants born to women with unknown hepatitis B surface antigen (HBsAg) status: Unintended impact of changes in recommendations

Holly Corwith-Jensen1, Ann R. Thomas1, Anthony Fiore2, Paul R. Cieslak1, and Hal Margolis3. (1) Acute and Communicable Disease Prevention, Oregon Department of Human Services, P.O. Box 14450, Portland, OR, USA, (2) Division of Viral Hepatitis, Centers for Disease Control and Prevention, Mailstop G37, Centers for Disease Control and Prevention, Atlanta, GA, USA, (3) Centers for Disease Control and Prevention, DEC, NA 6033, 1600 Clifton Road, NE, MS A-33, Atlanta, Georgia, USA


KEYWORDS:

BACKGROUND:
HB vaccine is recommended at birth for all infants, and is important for infants born to unscreened and HBsAg-positive women to prevent perinatal hepatitis B transmission. After controversy about mercury exposures from vaccines containing thimerosal, the American Academy of Pediatrics and the U.S. Public Health Service recommended in July 1999 that the first dose of HB vaccine be deferred until 2-6 months of age, but only for infants born to HBsAg-negative women.

OBJECTIVE(S):
To monitor the impact of this recommendation change on infants born to unscreened mothers, we measured HB vaccine coverage levels in Oregon before and after July 1999.

METHOD(S):
Infants were identified by reviewing electronic birth certificate data from 34 Oregon hospitals during April-June 1999 (before recommendation changes [T1]), August-October 1999 (after recommendations changes [T2]) and April-June 2000 (when resumption of pre-1999 practices were recommended [T3]). We verified maternal HBsAg screening and newborn HB vaccination by reviewing hospital records.

RESULT(S):
Of 16,515 births during the three time periods, 147 (1%) infants were born to women who were not screened for HBsAg before or during their hospitalization. During T1, 16/59 (27%) of these infants received HB vaccine within 12 hours of birth compared to 1/45 (2%) infants born during T2 (p=0.001) and 8/43 (19%) infants born during T3 (p=0.32 vs. T1). During T1, 47/59 (80%) infants received HB vaccine before discharge compared to 2/45 (4%) infants born during T2 (p<0.0001) and 22/43 (54%) infants born during T3 (p<0.002 vs. T1).

CONCLUSIONS(S):
HB vaccine coverage for infants born to unscreened women decreased significantly following the July 1999 announcement, and remained significantly lower 10-12 months later. When changes are made in established vaccination practices, practitioners need to ensure that such changes are not misinterpreted, resulting in failure to immunize appropriate groups. Efforts to re-establish routine administration of HB vaccine at birth are needed.

LEARNING OBJECTIVES:

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