Thirty-five years since the first hepatitis B virus (HBV) vaccine hit the market, people with major risk factors for the virus have a vaccination rate of less than 30%.

Publishing their findings in Clinical Infectious Diseases, Hope King, PhD, MSPH, an epidemiologist at the Centers for Disease Control and Prevention’s (CDC) Division of Viral Hepatitis, and her colleagues analyzed 2003 to 2014 data from the National Health and Nutrition Examination Surveys. They specifically looked at 18- to 49-year-old adults who had been tested for hep B and who reported at least one infection risk, including a history of sexually transmitted infections, being a man who has sex with men, having HIV and engaging in injection drug use.

The investigators split their analysis into three four-year time intervals, 2003 to 2006, 2007 to 2010 and 2011 to 2014, and calculated the proportion of people surveyed during each period whose testing indicated that they had hep B immunity due to vaccination.

During each successive period, 16.3%, 27.3% and 28.1% of the survey participants had been vaccinated for the virus, for an overall vaccination rate of 23.4%. The difference in the vaccination rate between the latter two periods was not statistically significant, meaning it may have been driven by chance, and therefore there was essentially no improvement in the rate between those times.

Having vaccine-induced immunity to HBV was associated with being younger, being female and having a higher level of education.

Writing about the unvaccinated study population as a whole, the study authors concluded: “Because these adults account for a substantial proportion of unprotected adults, targeted intervention strategies are essential to achieve the goal of hepatitis B elimination.

To read the study, click here.