CDC: Shorten Interval for Infants’ Post-Vaccine Hepatitis B Test

The U.S. Centers for Disease Control and Prevention (CDC) has recommended changes to the timing of postvaccination serologic testing (PVST) of infants born to mothers with hepatitis B virus (HBV) infection.

Within 12 hours of birth, neonates born to HBV-positive mothers currently receive the HBV vaccine and HBV immune globulin (HBIG) as postexposure prophylaxis against infection with virus. After this initial dose, these high-risk infants then complete a 3- or 4-dose series of HBV vaccines. Later, between 9 and 18 months of age, the infants undergo PVST to assess their response to the prophylactic regimen.

In a report published in the October 9 issue of its publication Morbidity and Mortality Weekly Report, the CDC recommends shortening  by 6 months the interval between the HBV vaccine series and PVST, calling for it to occur between 9 and 12 months of age.

"Providers should order PVST (consisting of hepatitis B surface antigen [HBsAg] and antibody to HBsAg [anti-HBs]) for infants born to HBsAg-positive mothers at age 9–12 months (or 1–2 months after the final dose of the vaccine series, if the series is delayed)," the report recommends.

This new advice has been issued in response to the discontinuation of production of Hib/HepB vaccine (Comvax), along with new data from the CDC's Enhanced Perinatal Hepatitis B Prevention Program that supports PVST 1 to 2 months after an infant gets the last HBV vaccine dose, and at age 9 months or older.

The report notes that for most infants born to mothers with HBV, testing between 9 and 12 months (in contrast with the traditional timetable of between 9 and 18 months) provided two opportunities for clinicians to assess these infants for infection—at the 9- and 12-month well-child visits. Moreover, it notes that the shortened interval to PVST shrinks the window of time in which infants who do not respond to prophylaxis are at risk of becoming infected with HBV from close contacts with the infection.

"Earlier PVST enables prompt revaccination of those infants needing revaccination with a second 3-dose HepB vaccine series to attain protective anti-HBs levels. A shortened interval might also increase adherence with recommendations for timely completion of PVST and conserve public health resources involved in providing case management services," the report says.

—Michael Gerchufsky, ELS, CMPP

Reference

Schillie S, Murphy TV, Fenlon N, Ko S, Ward JW. Update: shortened interval for postvaccination serologic testing of infants born to hepatitis B-infected mothers. MMWR Morb Mortal Wkly Rep. 2015;64(39):1118-1120.

About the photo: This digitally colorized transmission electron micrograph revealing the presence of hepatitis B virions. The large round virions are known as Dane particles. Credit: CDC/Dr. Erskine Palmer