Study Warns of More Chronic Hepatitis B in the Years Ahead

Shifting from a universal birth dose of the hepatitis B virus (HBV) vaccine to recently proposed strategies of deferred vaccination or a shared decision-making approach could increase chronic HBV infections, according to projections from a modeling study.

In a single-year U.S. birth cohort of 3.6 million infants, delaying the first vaccination dose until age 2 months would increase chronic HBV infections by 19% (255 to 303 cases), while the shared decision-making approach would increase chronic infections by 83% (467 cases), reported Amir Mohareb, MD, of Massachusetts General Hospital in Boston, and colleagues in the Annals of Internal Medicine.

“These estimates suggest that the relative increase in HBV infections would be substantial, although the absolute increase would remain modest, at least in the early years after a policy change,” they wrote. “If changes in CDC guidance result in an overall decrease in vaccine coverage, the effect on HBV infections will be even greater than what we report in the base-case scenario.”

If shared decision-making led to fewer HBV vaccinations, the result would be far more people entering adulthood susceptible to HBV infection — up to 1,806,000, compared with 232,000 with a universal birth-dose scenario at year 20, Mohareb and team noted. “These results should motivate policymakers and clinicians to consider reimplementation of the prior recommendation for universal childhood HBV vaccination at birth.”

Ninety percent of perinatally exposed newborns will develop chronic HBV infection, and one in four people with untreated chronic HBV infection will develop complications such as cirrhosis and hepatocellular carcinoma.

Universal HBV vaccination at birth has been shown to be safe and effective. Late last year, however, the CDC’s revamped Advisory Committee on Immunization Practices abandoned more than three decades of U.S. vaccine policy and voted to stop recommending a universal birth dose.

Instead, the panel recommended a shared clinical decision-making process for infants born to mothers who test negative for hepatitis B surface antigen. Under this guidance, parents and clinicians would decide “when or if” to administer the vaccine. For families opting not to give the birth dose, the panel suggested delaying the first dose until a child is 2 months old. The CDC’s proposed childhood immunization schedule would subject HBV vaccination to shared clinical decision-making except in high-risk groups.

The current study’s findings mirror the cautionary results of two similar modeling studies published earlier this year, which also warned of the potential dangers posed by skipping the universal birth dose.

In this study, Mohareb and colleagues also said that lower vaccination rates in delayed and shared decision-making scenarios could lead to even more chronic HBV infections by early adulthood.

If vaccine uptake were 75% in a delayed-vaccination scenario, there would be 357 chronic infections, 40% more than the estimated 255 cases under a birth-dose scenario. A 26% vaccination rate with shared decision-making would mean 575 chronic HBV infections, 125% more than the birth-dose estimate. Delayed vaccinations would lead to an estimated 912,000 young adults susceptible to HBV infection, while shared decision-making would boost that number to 2,665,000.

The authors also modeled a scenario that paired lower HBV birth-dose vaccination rates in infants of mothers who were HBV positive or had unknown HBV status with a greater population-wide HBV prevalence. In that scenario, deferred vaccination would result in 1,700 childhood chronic HBV infections, and shared decision-making would cause 2,192 such infections.

Study limitations included no simulations of liver disease development or death, nor did the models predict immunity levels in children who received only one or two doses of the three-dose HBV vaccination series.