How often is the Twinrix (hepatitis A and B vaccine) needed when traveling?

Twinrix Vaccination Schedule for Travelers

For travelers needing protection against both hepatitis A and B, complete the full Twinrix series using either the standard 3-dose schedule (0,1, and 6 months) or the accelerated 4-dose schedule (days 0,7,21-30, plus a booster at 12 months) depending on departure timing—this is not a vaccine you get repeatedly for each trip, but rather a one-time series that provides long-term protection. 1, 2

Initial Vaccination Series

Standard Schedule (Preferred When Time Permits)

• Three doses administered at 0,1, and 6 months provide optimal long-term protection 1, 2, 3
• At month 2 (after 2 doses), more than 99% of vaccinees achieve protection against hepatitis A and 84% against hepatitis B 3
• After completing all 3 doses, nearly all vaccinees have protective antibody levels against both viruses, with geometric mean titers of approximately 4818 mIU/ml for hepatitis B 3

Accelerated Schedule (For Last-Minute Travelers)

• Four doses on days 0,7, and 21-30, followed by a booster at 12 months when rapid protection is needed 1, 2, 4
• This accelerated regimen induces early protection and is specifically designed for travelers departing within weeks of planning their trip 5, 4
• The 12-month booster dose is essential for long-term immunity even with the accelerated schedule 1, 6

Long-Term Protection and Revaccination

Duration of Immunity

• Long-term follow-up data through 48 months shows all vaccinees remain positive for anti-HAV antibodies and >95% maintain protection against hepatitis B 3
• Vaccine-induced immunity persists for more than 30 years, meaning you do not need to repeat the series for subsequent trips 2
• Once the primary series is completed, no routine booster doses are needed for future travel 3

Special Considerations for Travelers

Who Should Receive Twinrix

• Travelers to countries with high or intermediate endemicity for both hepatitis A and B (Asia, Africa, Latin America, Middle East) 1, 5, 7
• The combined vaccine is specifically recommended when protection against both viruses is indicated, rather than using single-antigen vaccines separately 2

Timing Before Departure

• Start the first dose as soon as travel is considered, regardless of departure date 1
• For travelers departing in less than 2 weeks, older adults, immunocompromised persons, and those with chronic liver disease may need additional immune globulin (IG) alongside the first vaccine dose for optimal hepatitis A protection 1
• Note that limited data exist specifically for Twinrix in last-minute travel scenarios compared to single-antigen vaccines 1

Common Pitfalls to Avoid

• Do not restart the series if interrupted—simply continue where you left off, as restarting wastes doses and delays protection 2
• Do not assume you need revaccination before each trip—the primary series provides decades of protection 2, 3
• Do not give the third dose before 16 weeks from the first dose in the standard schedule, even if 8 weeks have passed since the second dose 2
• Do not skip the 12-month booster when using the accelerated schedule, as it is critical for long-term immunity 1, 6
• Do not use Twinrix if you only need hepatitis B protection—reserve it for patients requiring both vaccines 2