Despite Vaccines, Most U.S. Adults Not Immune to Hepatitis A or B

Even though vaccines exist, most U.S. adults still lack immunity to hepatitis A or B, according to a nationwide study. Only 40% showed serologic protection against hepatitis A (HAV), while 27% had immunity to hepatitis B (HBV), reported Dr. Giovanni Roldan of the University of Minnesota. Despite the vaccines being available for years and the recent expansion of universal adult HBV vaccination, these immunity levels remain suboptimal, especially among high-risk groups.

The researchers found that certain populations, such as those with dysglycemia, diabetes, immunosuppression, chronic liver disease, chronic kidney disease, significant alcohol use, and pregnant women, consistently had lower immunity levels. After Health Secretary Robert F. Kennedy Jr.'s influence led the CDC's Advisory Committee on Immunization Practices (ACIP) to reverse its stance on recommending a universal hepatitis B vaccine at birth, there are concerns that these immunity levels may drop further.

The study's findings, based on data from the 2017-2023 National Health and Nutrition Examination Survey (NHANES), serve as a baseline to assess the impact of these changes. Experts warn that the low HBV immunity in combination with the new ACIP recommendations could increase the risk for vulnerable populations. Similar suspensions of universal vaccine recommendations in other countries have led to increased disease rates, as seen with a resurgence of whooping cough after Japan temporarily halted pertussis vaccinations in the 1970s.