Most US adults lack immunity to hepatitis A or B

Clinical takeaway: Routinely assess hepatitis A and B vaccination status, particularly in patients with chronic liver disease, chronic kidney disease, diabetes, immunosuppression, significant alcohol use, or pregnancy, and offer vaccination when indicated.

Despite longstanding vaccine availability and recommendations, most US adults remain susceptible to hepatitis A and/or hepatitis B, highlighting missed opportunities for vaccination and prevention.

A cross-sectional analysis of National Health and Nutrition Examination Survey (NHANES) data from 2017 to 2023 found that protection against hepatitis A virus (HAV) and hepatitis B virus (HBV) remains surprisingly low across the US adult population. Among 13,514 participants representing an estimated 226 million US adults, only 39.5% had serologic immunity to HAV and 27.1% had serologic immunity to HBV. Vaccine-derived HBV immunity was identified in just 25.2% of adults.

The findings suggest that roughly 6 in 10 adults lack HAV immunity and nearly 3 in 4 lack evidence of HBV immunity.

Immunity levels were also suboptimal in groups at higher risk for infection or complications. Across high-risk populations, HAV immunity ranged from 26.7% to 63.7%, while vaccine-derived HBV immunity ranged from 14.0% to 38.6%, indicating persistent vulnerability among many patients who stand to benefit most from vaccination.

Older adults appeared particularly underprotected against HBV. Among adults aged 65 years or older, only 13.5% had HBV immunity, although 39% had HAV immunity.

As the authors noted, “population-level serologic immunity to HAV and HBV was suboptimal and substantial susceptibility persisted across high-risk clinical subgroups,” underscoring the need for “targeted, systematic vaccination strategies.”

Overall, the data point to substantial gaps in viral hepatitis protection across the US and support more consistent screening of vaccination status and proactive immunization efforts in routine clinical care.

Source: Roldan GA, et al. (2026 Aug 17) JAMA Intern Med. Serologic Immunity to Hepatitis A and B in US Adults and High-Risk Populations