Only 27.1% of US adults have blood-test evidence of immunity to hepatitis B, according to a cross-sectional study published August 17, 2026 in JAMA Internal Medicine. The analysis covered 13,514 people in the National Health and Nutrition Examination Survey from January 2017 to August 2023, weighted to represent about 226.1 million US adults, and it found the thinnest protection in the groups that face the worst outcomes from infection, including just 14.0% of people with chronic kidney disease.
Key takeaways
- 27.1% of US adults were immune to hepatitis B, about 61.3 million people. Most of that came from vaccination: 25.2% had vaccine-derived immunity.
- Hepatitis A immunity was 39.5%, roughly 89.4 million adults.
- Among high-risk groups, vaccine-derived hepatitis B immunity ran from 14.0% in chronic kidney disease up to 38.6% in pregnancy.
What the study found
The researchers, led by Giovanni A. Roldan, MD, defined hepatitis B immunity by a positive hepatitis B surface antibody test, and counted immunity as vaccine-derived when the surface antibody was positive without hepatitis B core antibodies.
For hepatitis B, 27.1% of adults were immune (95% CI, 25.8%-28.4%), a figure the survey design pins down to within about a percentage point either way. Vaccine-derived immunity was 25.2%. For hepatitis A, 39.5% were immune.
The subgroup numbers are the story. Vaccine-derived hepatitis B immunity ranged from 14.0% in chronic kidney disease to 38.6% in pregnancy. Hepatitis A immunity ranged from 26.7% in people with metabolic dysfunction-associated alcohol-related liver disease to 63.7% in people with chronic hepatitis B infection.
The authors conclude that “population-level serologic immunity to HAV and HBV was suboptimal and substantial susceptibility persisted across high-risk clinical subgroups.”
Dr. Kumar’s take
The headline number is a measurement, not a survey answer. Nobody was asked whether they remembered getting the shots. Blood was drawn and tested, and in a nationally representative sample of 13,514 adults, close to three out of four had no antibody to show for it.
Look at where the protection comes from. Of the 27.1% of adults who were immune, almost all of it was vaccine-derived, at 25.2%. The missing protection is not a matter of people who never happened to encounter the virus. It is people who never completed the vaccine series.
The chronic kidney disease finding is the one that should bother clinicians most. That group came in last of every high-risk subgroup the authors looked at, at 14.0% vaccine-derived immunity, or roughly one in seven. That is less than half the rate seen in pregnancy, which topped the list at 38.6%. The subgroup with the most to lose from hepatitis B infection is the one with the least protection against it.
One limit is worth stating. This is a snapshot in time, not a record of who got vaccinated, and surface antibody levels fall in the years after a completed series, so some people counted here as unprotected did receive their shots.
That does not rescue the headline. Even a generous reading leaves tens of millions of adults with no measurable protection against a virus that causes liver failure and liver cancer, and the shortfall is worst where the liver is already sick. Adult vaccination keeps showing this pattern of clear benefit and thin uptake, as with the signal that the shingles vaccine may cut dementia risk by a third in older adults. NHANES has been surfacing gaps like this for years, including metabolic syndrome on the rise: 34% of US adults affected.
What it means for you
Do not assume childhood shots settled this. Plenty of adults were never offered the hepatitis B series unless a job or a specific risk factor triggered the conversation.
Hepatitis B immunity is a simple blood test. Ask your doctor for a hepatitis B surface antibody level. A positive result generally means you are protected, either from a completed vaccine series or from recovering from past infection.
Move this to the front of the list if you have chronic kidney disease or are approaching dialysis, chronic liver disease, or diabetes, or if you are pregnant or planning to be. These are the groups already named in the vaccination recommendation and the groups with the lowest measured protection.
If the antibody is absent and you never completed a series, the vaccine is available at most pharmacies and primary care offices. People on dialysis need the higher-dose schedule, so say so at the visit rather than assuming the standard adult dose is what gets drawn up.