Roughly 5 percent of healthy people are hepatitis B vaccine non-responders. The non-response rate is higher among people who are undergoing dialysis or are immune suppressed. Among people with hepatitis C, one study reported a 45 percent non-response rate. People with genotype 1 hepatitis C had an even higher non-response rate.
The Centers for Disease Control and Prevention (CDC) recommends booster doses for people who are immunocompromised or on dialysis. The CDC does not specifically address what to do about people with hep C who don’t respond to hep B vaccination. Some doctors will give booster shots or a series of intra-dermal injections. Additional doses of hep B vaccine are not harmful, assuming you are not allergic.