TWINRIX

What it is

TWINRIX is a non-infectious combination vaccine containing hepatitis A virus antigen and hepatitis B surface antigen. Each 1 mL dose of TWINRIX contains 720 ELISA units of hepatitis A virus antigen and 20 micrograms of hepatitis B surface antigen. TWINRIX Junior contains 360 ELISA units of hepatitis A virus antigen and 10 micrograms of hepatitis B surface antigen in a 0.5 mL dose.

Approved indications

— Active immunisation against hepatitis A and hepatitis B virus infection in adults and children from 1 year of age.

Dosing overview

TWINRIX (720/20) is indicated for active immunisation against hepatitis A and hepatitis B virus infection in adults and children from 1 year of age, while TWINRIX Junior (360/10) is indicated for use in children aged 1 to 15 years. For adults and children not previously exposed to hepatitis A or hepatitis B viruses or vaccines, dosing schedules vary:

The rapid schedule is used in exceptional circumstances in adults when more rapid protection is required, for example in travellers commencing vaccination within one month or more of departure. When the rapid schedule is used, a fourth dose is recommended 12 months after the first dose to ensure adequate protection, as lower seroprotection rates against hepatitis B were observed after the third dose as compared to the standard 0, 1, 6 month schedule. The need for a booster dose in healthy individuals who have received a full primary vaccination course has not been established, and thus a booster dose is not recommended in these circumstances.

Key safety warnings

TWINRIX should never be administered intravenously. Syncope (fainting) can occur following, or even before, any vaccination as a psychogenic response to the needle injection, and it is important that procedures are in place to avoid injury from faints. TWINRIX should be administered with caution to subjects with thrombocytopenia or a bleeding disorder since bleeding may occur following an intramuscular administration to these subjects. In elderly subjects, haemodialysis patients and persons with an impaired immune system, adequate anti-HAV and anti-HBs antibody titres may not be obtained after a primary vaccination course, and the monitoring of antibody titres and if appropriate the need for additional doses of the appropriate vaccine should be considered in such patients. It is possible that subjects may be in the incubation period of a hepatitis A or hepatitis B infection at the time of vaccination, and it is not known whether TWINRIX will prevent hepatitis A and hepatitis B in such cases. These vaccines will not induce the production of anti-HBs antibodies in hepatitis B carriers and will not protect against infection caused by hepatitis C or hepatitis E viruses, or other pathogens known to infect the liver.

Contraindications

TWINRIX should not be administered to subjects with known hypersensitivity to any component of the vaccine or to subjects having shown signs of hypersensitivity after previous administration of these combined vaccines or the monovalent hepatitis A or hepatitis B vaccines. TWINRIX should not be administered to subjects suffering from acute severe febrile illness; however, the presence of minor infection does not contraindicate vaccination.

Regulatory history

TWINRIX and TWINRIX Junior were first registered on the ARTG on 18 October 2007.