What is Twinrix Adult?
Twinrix Adult is a vaccine available as a suspension for injection. It contains inactivated (ie killed) hepatitis A virus and parts of the hepatitis B virus as active substances. It is available in 1 ml ampoules and 1 ml pre-filled syringes.
What is Twinrix Adult used for?
Twinrix Adult is used to protect against hepatitis A and hepatitis B infection (diseases affecting the liver). The vaccine can be given to adults and adolescents aged 16 and over who are not already immune to these two diseases and who are risk of contracting both.
The medicine can only be obtained with a prescription.
How is Twinrix Adult used?
The recommended vaccination protocol for Twinrix Adult consists of three doses, with an interval of one month between the first two doses and a five-month interval between the second and third. The vaccine is injected into the muscle of the upper arm.
The three injections can exceptionally be given over a three week period for adults who need quick protection before a trip. In these cases, a fourth injection is recommended 12 months after the first dose.
Those given the first dose must necessarily complete the full protocol for Twinrix Adult. A booster dose of Twinrix Adult, or a different vaccine for hepatitis A or B, can be given according to official recommendations.
How does Twinrix Adult work?
Twinrix Adult is a vaccine. Vaccines work by "teaching" the immune system (the body's natural defenses) to defend itself against a disease. Twinrix Adult contains a tiny amount of inactivated hepatitis A virus and "surface antigen" (surface proteins) of the virus. of hepatitis B. When a person receives the vaccine, the immune system recognizes the viruses and surface antigens as 'foreign' and makes antibodies against them. to produce antibodies faster. Antibodies help protect the body from diseases related to these viruses.
The vaccine is "adsorbed". This means that the viruses and surface antigens are fixed on aluminum compounds to stimulate a better response. The surface antigens of the hepatitis B virus are produced by a method called the 'recombinant DNA technique', meaning they are made by a yeast that has received a gene (DNA) that makes it capable of producing proteins.
The active substances of Twinrix Adult have been available in the European Union (EU) for several years in separate vaccines: Havrix Adult for protection against hepatitis A and Engerix-B for protection against hepatitis B.
How has Twinrix Adult been studied?
Twinrix Adult has been studied in three main studies involving 843 healthy people between the ages of 18 and 60, most of them under the age of 40. Each person received Twinrix Adult doses on month 0, 1 and 6 of the protocol. The main measure of effectiveness was the percentage of people who developed antibodies to hepatitis A and B.
Other studies have observed the persistence of antibodies both after vaccination in adults and adolescents and with the three-week adult rapid protection protocol.
What benefit has Twinrix Adult shown during the studies?
Studies have shown that, for hepatitis A, antibodies were detected in 94% of adults after the first dose, in 99.5% after the second dose, and in 100% after the third dose. For hepatitis B, antibodies were detected in 71% of adults after the first dose, 97% after the second dose and 99.7% after the third dose.
Other studies have shown the presence of antibodies for up to five years. The three-week vaccination protocol also resulted in the production of antibodies in approximately 83% of patients, up to approximately 89% after the booster dose at month 12.
What is the risk associated with Twinrix Adult?
The most common side effects of Twinrix Adult (seen in more than 1 in 10 doses of the vaccine) are headache, pain and redness at the injection site, and fatigue (tiredness). For the complete list of side effects reported with Twinrix Adult, see the package leaflet.
Twinrix Adult must not be used in people who may be hypersensitive (allergic) to any of the active substances, to any of the other ingredients or to neomycin (an antibiotic). It should also not be used in people who have had an allergic reaction after receiving hepatitis A or hepatitis B vaccines. Twinrix Adult vaccination should be postponed in patients with a sudden high fever. Twinrix Adult must never be injected into a vein.
Why has Twinrix Adult been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that Twinrix Adult's benefits are greater than its risks for use in adults and non-immune adolescents from 16 years of age who are at risk of infection with either Hepatitis A versus hepatitis B. The Committee recommended the granting of a Marketing Authorization for Twinrix Adult.
Other information about Twinrix Adult:
On September 20, 1996, the European Commission released GlaxoSmithKline Biologicals s.a. a "Marketing Authorization" for Twinrix Adults, valid throughout the European Union. The "Marketing Authorization" was renewed on September 20, 2001 and September 20, 2006.
For the full version of the Twinrix Adult EPAR click here.
Last update of this summary: 02-2008.
The information on Twinrix Adult published on this page may be out of date or incomplete. For a correct use of this information, see the Disclaimer and useful information page.
