From the Guidelines
Hepatitis A and B titers are essential blood tests to determine immunity against these viral infections, and if you need to check your immunity status, these lab tests are recommended before considering vaccination. For hepatitis A, the test measures total anti-HAV antibodies, while hepatitis B testing typically includes HBsAb (surface antibody) levels. If titers show you're not immune, vaccination is recommended, with the hepatitis A vaccine requiring two doses given 6-12 months apart, and the hepatitis B vaccine following a three-dose schedule at 0,1, and 6 months 1. Alternatively, you can receive the combined hepatitis A and B vaccine (Twinrix) in three doses over 6 months. These vaccinations are particularly important for healthcare workers, travelers to endemic regions, people with chronic liver disease, men who have sex with men, and injection drug users, as they are at higher risk of infection and complications 1. Immunity testing is valuable because some people may have developed natural immunity from previous exposure without knowing it, potentially avoiding unnecessary vaccination. Key populations, such as those with chronic liver disease, should also undergo testing for IgG anti-HAV and receive HAV vaccine if they have a negative immune status for hepatitis A 1. It's also important to note that anti-HBs levels of ≥10 mIU/mL are generally considered seroprotective, and testing for anti-HBs should be performed 1–2 months after administration of the final dose of the vaccine series 1. Overall, hepatitis A and B vaccinations are crucial for preventing these infections and their potential complications, and immunity testing can help guide vaccination decisions. Some key points to consider include:
- Hepatitis A and B titers are essential for determining immunity
- Vaccination is recommended if titers show no immunity
- Certain populations are at higher risk and should be prioritized for vaccination
- Immunity testing can help avoid unnecessary vaccination
- Anti-HBs levels should be tested after vaccination to confirm seroprotection.
From the Research
Hepatitis A and Hepatitis B Vaccination
- Hepatitis A virus (HAV) and hepatitis B virus (HBV) are vaccine-preventable, with current recommendations advocating vaccination of non-immune adults at risk of exposure 2.
- The combination hepatitis A and hepatitis B vaccine (Twinrix) can be administered on an accelerated schedule, providing rapid initial protection for individuals who require quick immunization, such as last-minute travelers and short-term correctional facility inmates 2.
- Immunization rates against HAV and HBV are low, particularly among high-risk groups, including men who have sex with men, injection drug users, and travelers to endemic areas 3.
Vaccine Efficacy and Safety
- The combined hepatitis A and B vaccine has been shown to be safe and immunogenic, with anti-HAV seropositivity rates ranging from 96.2% to 100% and anti-HBs seroprotection rates from 82% to 100% 4.
- The vaccine offers satisfactory long-term immunogenicity rates, expected duration of protection, and a safety profile similar to monovalent hepatitis A or B vaccines 4.
- A new novel hepatitis B vaccine given in two doses one month apart is available and has increased efficacy in adults 5.
Recommendations for Vaccination
- The Advisory Committee on Immunization Practices recommends universal HepB vaccination for adults aged 19-59 years, including pregnant persons, and adults aged ≥60 years with risk factors for hepatitis B 6.
- Hepatitis A vaccine is a main component of travel vaccination practices, and its use is warranted for wider local use due to recent outbreaks related to imported foods and urban transmission among homeless individuals 5.