How do we complete the Hepatitis B (Hep B) vaccine series for a patient who has received two doses of Twinrix (Hepatitis A and Hepatitis B vaccine)?

From the Guidelines

To complete the Hepatitis B vaccine series for a patient who has already received two doses of Twinrix, you should administer one additional dose of a monovalent Hepatitis B vaccine (such as Engerix-B or Recombivax HB) at least 8 weeks after the second Twinrix dose and at least 16 weeks after the first dose, as recommended by the Advisory Committee on Immunization Practices in 2022 1. The patient has already received two doses of Twinrix, which contains a full adult dose of Hepatitis A vaccine but only half the standard adult dose of Hepatitis B vaccine in each injection.

• The standard adult dose for Engerix-B is 1.0 mL (20 mcg) and for Recombivax HB is 1.0 mL (10 mcg), administered intramuscularly in the deltoid muscle.
• Two doses of Twinrix provide only two of the three standard doses of Hepatitis B vaccine needed for complete protection, as outlined in the recommended doses and schedules of hepatitis B vaccine for adults aged ≥18 years and persons aged 11–19 years, by vaccine type and age group 1.
• Completing the series ensures the patient develops adequate antibody levels for long-term protection against Hepatitis B infection.
• No additional Hepatitis A vaccination is needed as two doses of Twinrix already provide complete Hepatitis A protection. It is essential to follow the recommended schedule to ensure the patient receives the necessary protection against Hepatitis B infection, as interrupted schedules do not require restarting the series, but doses should be administered as soon as possible, with the final dose given at least 8 weeks after the second dose and at least 16 weeks after the first dose 1.

From the FDA Drug Label

Interchangeability With Other Hepatitis B Vaccines: ... A controlled study (N = 48) demonstrated that completion of a course of immunization with 1 dose of ENGERIX-B (20 mcg, month 6) following 2 doses of RECOMBIVAX HB® * (10 mcg, months 0 and 1) produced a similar GMT (4,077 mIU/mL) to immunization with 3 doses of RECOMBIVAX HB (10 mcg, months 0,1, and 6; 2,654 mIU/mL). Thus, ENGERIX-B can be used to complete a vaccination course initiated with RECOMBIVAX HB.

The patient who has received two doses of Twinrix can complete the Hepatitis B vaccine series with one more dose of a Hepatitis B vaccine, such as ENGERIX-B, as the interchangeability of Hepatitis B vaccines has been demonstrated 2. The exact timing of this final dose is not specified in the provided text, but based on standard vaccination schedules, it would typically be given 1-2 months after the second dose of Twinrix, but the decision should be made based on clinical judgment and consideration of the patient's individual situation. Key points to consider:

• The patient has already received two doses of Twinrix, which contains both Hepatitis A and Hepatitis B vaccines.
• The final dose of the Hepatitis B vaccine series can be given as a single dose of a Hepatitis B vaccine, such as ENGERIX-B.
• The decision on the timing of the final dose should be made based on clinical judgment and consideration of the patient's individual situation.

From the Research

Completing the Hepatitis B Vaccine Series with Twinrix

To complete the Hepatitis B (Hep B) vaccine series for a patient who has received two doses of Twinrix, we need to consider the standard vaccination schedule and the immunogenicity of the vaccine.

• The standard vaccination schedule for Twinrix is 0,1, and 6 months 3.
• After two doses, the patient has likely developed some level of immunity against Hepatitis B, but a third dose is typically required to achieve optimal protection 3, 4.
• Studies have shown that the third dose of Twinrix induces a significant increase in geometric mean titers (GMTs) and provides long-term protection against Hepatitis B 3, 5.
• However, there is also evidence to suggest that a two-dose schedule can be effective in certain populations, such as children aged 6-15 years 6.
• It is essential to note that the patient's individual circumstances, such as their age, health status, and risk of exposure to Hepatitis B, should be taken into account when determining the best course of action.

Recommendations

Based on the available evidence, it is recommended that the patient receive a third dose of Twinrix to complete the Hepatitis B vaccine series, unless there are specific contraindications or concerns that need to be addressed.

• The third dose should be administered according to the standard schedule, which is typically 6 months after the second dose 3.
• Alternatively, an accelerated vaccination schedule may be considered in certain situations, such as for individuals who are at high risk of exposure to Hepatitis B 7.
• Ultimately, the decision to complete the Hepatitis B vaccine series with a third dose of Twinrix should be made in consultation with a healthcare professional, taking into account the patient's individual needs and circumstances.