Up to 10 percent of people who received the complete series of three hepatitis B shots do not respond. We aren’t sure if there is no immunity, or if their counts are below the threshold for immunity. In either case, most experts recommend additional vaccination.

Research presented at the 2018 Liver Meeting found that patients who did not respond to initial vaccine series benefited from re‐immunization by repeating the vaccine or a single higher dose vaccine booster. (Beshoy Yanny, et al.) Subcutaneous injection route increased response in patients with HIV by 12 percent.

Talk to your health care provider about getting a higher dose hep B booster or repeating the series. Ask if a subcutaneous injection might be appropriate for you. This type of injection is given into a layer of fat under the skin rather than in to the muscle.