Daronrix

What is Daronrix?

Daronrix is ​​a vaccine. Daronrix is ​​a suspension for injection containing inactivated (killed) influenza viruses. The vaccine contains a strain of the influenza virus called A / Viet Nam / 1194/2004 (H5N1).

What is Daronrix used for?

Daronrix is ​​a vaccine that can only be used for flu prophylaxis in a situation officially declared as a "pandemic" by the World Health Organization (WHO) or the European Union (EU). An influenza pandemic occurs when it is detected. a new type (strain) of influenza virus capable of being transmitted without difficulty from person to person due to the lack of immunity (protection) among the population. A pandemic can affect most nations and regions of the world. Daronrix would be administered according to official recommendations.
The vaccine can only be obtained with a prescription.

How is Daronrix used?

Daronrix is ​​used in two doses, at least three weeks apart. The vaccine is given by intramuscular injection in the upper arm.

How does Daronrix work?

Daronrix is ​​a so-called "prototype" vaccine, which is a special type of vaccine that can be produced to fight a pandemic. Before a pandemic occurs, no one knows which flu strain will be involved, so manufacturers are unable to prepare a suitable vaccine in advance. For this reason, a vaccine is produced that contains a specially selected strain of influenza virus because no one has been exposed to it and against which, therefore, no one is immune. This vaccine can be tested to observe reactions in humans and to have the ability to predict how people will react if the flu strain responsible for the pandemic is included in the vaccine.
Vaccines work by "teaching" the immune system (the body's natural defense system) to defend itself against a disease. Daronrix contains small amounts of a virus called H5N1. The virus is intact, but has been inactivated (killed) in such a way. in the event of a pandemic, the viral strain in Daronrix will be replaced by the strain responsible for the pandemic before the vaccine is used.
When a person is vaccinated, the immune system recognizes the inactivated virus as "foreign" and makes antibodies against that virus. If exposed to the virus after vaccination, the immune system will be able to produce antibodies more quickly.
The body can then protect itself from diseases caused by these viruses. The vaccine also contains an 'adjuvant' (a compound containing aluminum) to stimulate a better response.

How has Daronrix been studied?

The effects of Daronrix were first tested in experimental models before being studied in humans. The main study of Daronrix involved 387 healthy adults; the study compared the ability of different doses of Daronrix, with or without adjuvant, to stimulate the production of antibodies (immunogenicity). Participants were given two injections of Daronrix, containing one of four different doses of hemagglutinin (a protein found in influenza viruses), with or without the adjuvant, 21 days apart. The main measure of effectiveness was the levels of antibodies to the influenza virus detected in the patients' blood before vaccination, on the day of the second injection (day 21) and 21 days later (day 42).

What benefit has Daronrix shown during the studies?

According to the criteria defined by the Committee for Medicinal Products for Human Use (CHMP), a mock-up vaccine must induce protective levels of antibodies in at least 70% of people vaccinated to be considered adequate.
The study showed that Daronrix containing 15 micrograms of hemagglutinin and the adjuvant produced an antibody response that met these criteria. At 21 days after the second injection, 70.8% of vaccinated people had antibody levels capable of guaranteeing protection. from the "H5N1.

What is the risk associated with Daronrix?

The most common side effects seen with Daronrix (seen in more than 1 in 10 patients) are headache, pain and redness at the injection site, and fatigue. These reactions usually disappear within 1-2 days without treatment. For the full list of the side effects reported with Daronrix, see the package leaflet.
Daronrix must not be given to patients who have had an anaphylactic reaction (severe allergic reaction) to any of the constituents of the vaccine or to any substance found in trace amounts in the vaccine, such as eggs, chicken protein, gentamicin sulfate (an antibiotic). However, in a pandemic situation, it may be appropriate to administer the vaccine to these patients, provided that resuscitation equipment is readily available.

Why has Daronrix been approved?

The CHMP (Committee for Medicinal Products for Human Use) concluded that Daronrix's benefits are greater than its risks and that its suitability as a mock-up vaccine in anticipation of an influenza pandemic has been demonstrated. The Committee therefore recommended the granting of a marketing authorization for Daronrix. Daronrix was authorized under "exceptional circumstances". This means that, as the strain of influenza virus that could cause a pandemic is not known, it has not been possible to obtain comprehensive information on the future pandemic vaccine. The European Medicines Agency (EMEA) reviews the new information available annually and updates this summary if necessary.

What information is still awaited for Daronrix?

If the pandemic is officially declared, and if the Daronrix company decides to market the vaccine, the company will introduce the strain responsible for the flu into the vaccine. The company will collect information on the safety and efficacy of the pandemic vaccine and submit this data to the CHMP. for an evaluation.

What measures are being taken to ensure the safe use of Daronrix?

If Daronrix is ​​to be used during a pandemic, the manufacturer will collect information on the safety of the vaccine during its use, including information on side effects and its safety in children, pregnant women, critically ill patients and people with problems. borne by the immune system.

Other information about Daronrix:

On 21 March 2007, the European Commission released GlaxoSmithKline Biologicals s.a. a "Marketing Authorization" for Daronrix valid throughout the European Union. For the full version of the Daronrix EPAR click here.

Last update of this summary: 03-2007.

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