What is Pandemrix?
Pandemrix is a vaccine given by injection. It contains fractions of influenza viruses that have been inactivated (killed). Pandemrix contains an influenza strain called A / California / 7/2009 (H1N1) strain type v (X-179A).
What is Pandemrix used for?
Pandemrix is a vaccine to protect against "pandemic flu". It should only be used for pandemic flu A (H1N1) which was officially declared by the "World Health Organization" on 11 June 2009. A "pandemic flu is it occurs when a new strain of influenza virus can easily spread from person to person because you are not immunized (protected) against it.A pandemic can affect most countries and regions around the world. Pandemrix is administered based on official recommendations.
The medicine can only be obtained with a prescription.
How is Pandemrix used?
Pandemrix is given as a single dose by injection into the shoulder muscle. After an interval of at least three weeks, a second dose can be given. The second dose should be given to children aged 6 months to 9 years.
How does Pandemrix work?
Pandemrix is a vaccine. Vaccines work by "teaching" the immune system (the body's natural defenses) how to defend itself against a disease. Pandemrix contains small amounts of hemagglutinins (surface proteins) of a virus called A (H1N1) v which is causing the current pandemic. The virus was first inactivated so as not to cause any disease.
When a person is vaccinated, the immune system recognizes the virus as "foreign" and makes antibodies against that virus. If the body is exposed to the virus again, the immune system will be able to produce antibodies more quickly. This will help protect the body against disease caused by the virus.
Before use, the vaccine is prepared by mixing a suspension that contains virus particles with a solvent. The resulting "emulsion" will be injected. The solvent contains an "adjuvant" (an oil-containing compound) to enhance the immune response.
How has Pandemrix been studied?
Pandemrix was initially developed as a mock-up vaccine using a H5N1 strain of the influenza virus named A / Vietnam / 1194/2004. The company investigated the ability of this prototype vaccine to trigger the production of antibodies. ("immunogenicity") against this influenza virus strain prior to the pandemic.
After the onset of the H1N1 pandemic, the company replaced the viral strain in Pandemrix with the pandemic-causing strain H1N1 and submitted data on this substitution to the Committee for Medicinal Products for Human Use (CHMP).
The company presented the results of three ongoing studies:
• In a study of 130 healthy adults aged 18 to 60 years, the ability of Pandemrix H1N1 (with a two-dose dosing schedule) to trigger an immune response is compared with that of an experimental vaccine that contains an amount of viral material. four times higher without adjuvant;
- One study compares the ability of Pandemrix (in a two-dose dosing schedule) with that of Pandemrix in single-dose to trigger an immune response in 120 healthy older subjects over 60 years of age;
- In a study in healthy children aged 6 months to 35 months, the efficacy of Pandemrix at the "full dose" of 0.5ml was compared with the "half dose" of 0.25ml.
What benefit has Pandemrix shown during the studies?
The mock-up vaccine has been shown to induce protective levels of antibodies in at least 70% of the people in which it has been studied. In line with the criteria set by the CHMP, this demonstrated that the vaccine induced an adequate level of protection. The CHMP also expressed satisfaction that the change of the strain to H1N1 did not affect the characteristics of the vaccine.
In all three ongoing studies, the CHMP looked at how the first dose was able to trigger a satisfactory immune response. In the adult study, in which 61 subjects were given the marketed formulation of Pandemrix H1N1, the percentage of subjects with an antibody level in their blood high enough to neutralize the H1N1 virus (seroprotection rate) was 100% . In the older subjects study, this rate was 87% (based on data on 120 subjects), and in the children study 100% (based on data on the first 51 children included in the study).
What is the risk associated with Pandemrix?
The most common side effects associated with Pandemrix (seen in more than one in 10 vaccine doses) are dizziness, arthralgia (joint pain), myalgia (muscle pain), injection site reactions (induration, swelling, pain and redness), fever and fatigue (tiredness). For the full list of side effects reported with Pandemrix, see the package leaflet.
Pandemrix must not be used in people who have had an anaphylactic reaction (severe allergic reaction) to any of the ingredients in the vaccine or to any of the substances found in very low concentrations in the vaccine, such as chicken or egg proteins, ovalbumin (a protein found in egg white), formaldehyde, gentamicin sulfate (an antibiotic) and sodium deoxycholate. However, in the event of a pandemic, it may be appropriate to administer the vaccine to these patients, provided the necessary equipment is available for resuscitation.
Why has Pandemrix been approved?
The CHMP decided that, based on the information obtained with the mock-up vaccine and the information provided on the change of strain, the benefits of Pandemrix outweigh its risks for influenza prophylaxis in the officially declared H1N1 pandemic situation. The Committee recommended. the release of the marketing authorization for Pandemrix.
Pandemrix was authorized under "exceptional circumstances". This means that it has not been possible to obtain complete information on the pandemic vaccine. The European Medicines Agency will review any new data that becomes available each year, updating this summary as appropriate.
What information is still awaited for Pandemrix?
The company that makes Pandemrix will collect information on the safety and efficacy of the vaccine and will submit this data to the CHMP for evaluation.
What measures are being taken to ensure the safe use of Pandemrix?
The company that makes Pandemrix will collect information on the safety and efficacy of the vaccine during its use, ie information on its side effects and safety in children, the elderly, pregnant women, patients with serious illnesses and people with medical problems. to the immune system.
Other information about Pandemrix:
On May 20, 2008, the European Commission released GlaxoSmithKline Biologicals s.a. a "Marketing Authorization" for the Pandemrix H5N1 prototype vaccine, valid throughout the European Union. The "Marketing Authorization" for the H1N1 vaccine was granted on 29 September 2009.
For the full EPAR of Pandemrix with the most up-to-date information on the use of the vaccine, click here.
Last update of this summary: 11-2009.
The information on Pandemrix - influenza vaccine 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.
