Perinatal HBV: Timely Immunoprophylaxis Effective

April 20, 2015

Approximately 1% of infants experience perinatal hepatitis B virus (HBV) infection despite having received recommended immunoprophylaxis, according to a new study. The greatest risk for infection occurred in infants whose mothers were younger, hepatitis B e-antigen–positive, or had a high viral load. Infants who received fewer than three hepatitis B vaccine doses were also at increased risk.

Sarah Schillie, MD, MPH, MBA, from the Centers for Disease Control and Prevention in Atlanta, Georgia, and colleagues published their prospective analysis in an article published online April 20 in Pediatrics. They evaluated 17,951 mother–infant pairs and 9252 infants born to women in the US Enhanced Perinatal Hepatitis B Prevention Programs (EPHBPPs) who were positive for the hepatitis B surface antigen.

The number of hepatitis B vaccine doses correlated with risk for infant infection. Infection occurred in 3 (6.7%) of 45 infants who received fewer than three doses of vaccine compared with 97 (1.1%) of 9207 infants who received three or more doses (P = .01).

The investigators found that younger women were more likely to be hepatitis B antigen–positive and to transmit HBV to their babies (P = .01). Infected infants were also more likely to be born to women who had viral loads of 2000 IU/mL or higher compared with those with viral loads lower than 2000 IU/mL (P = .04).

Perinatal HBV prevention is accomplished via a combination of timely immunoprophylaxis and a three-dose series of hepatitis B vaccine. The study confirms that this approach appears to prevent most HBV transmission, thereby reducing HBV-related morbidity and mortality. The study also underscores the challenge of how best to reduce transmission below the current 1%.

"Although previous studies have established an increased risk of perinatal HBV transmission with immunoprophylaxis delays, our data were too sparse to assess the effect of delayed prophylaxis on infection status," the authors write.

Although immunoprophylaxis has obvious benefits, it also brings with it risks. In an accompanying editorial, Ravi Jhaveri, MD, from the University of North Carolina at Chapel Hill, discusses the evaluation that must now take place.

"Further studies are important because there are tangible downstream risks to using antiviral agents during pregnancy. Women in the 'immune tolerant' phase of chronic HBV, with HBV e-antigen positive and high-level HBV DNA in the absence of symptoms or elevated liver enzymes, may transition to a more active phase of hepatitis when treatment is stopped postpartum. Despite the published warning, there is likely little infant drug exposure if a woman breastfeeds while taking tenofovir, but fetal drug exposure before delivery could have some long-term effect that is not yet appreciated," he writes.

The authors and Dr Jhaveri have disclosed no relevant financial relationships.

Pediatrics. Published online April 20, 2015. Article abstract


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