In accordance with the marketing authorisation, the use of Pandemrix™ (H1N1) in a pandemic situation will be closely monitored with regular periodic safety update reports being prepared on a monthly basis. In addition, the safety data from 11 ongoing clinical trials will be made available as soon as possible as well as pharmacovigilance data.
The Pandemrix™ (H1N1) Summary of Product Characteristics includes full details concerning:
Special warnings and precautions for use:
Caution is needed when administering this vaccine to persons with a known hypersensitivity (other than anaphylactic reaction) to the active substance, to any of the excipients, to thiomersal and to residues (egg and chicken protein, ovalbumin, formaldehyde, gentamicin sulphate and sodium deoxycholate).
As with all injectable vaccines, appropriate medical treatment and supervision should always be readily available in case of a rare anaphylactic event following the administration of the vaccine.
If the pandemic situation allows, immunisation should be postponed in patients with severe febrile illness or acute infection.
Pandemrix™ (H1N1) should under no circumstances be administered intravascularly. There are no data with Pandemrix™ (H1N1) using the subcutaneous route. Therefore, healthcare providers need to assess the benefits and potential risks of administering the vaccine in individuals with thrombocytopenia or any bleeding disorder that would contraindicate intramuscular injection unless the potential benefit outweighs the risk of bleedings.
There are no data on administration of AS03-adjuvanted vaccines before or following other types of influenza vaccines intended for pre-pandemic or pandemic use.
Antibody response in patients with endogenous or iatrogenic immunosuppression may be insufficient.
A protective immune response may not be elicited in all vaccinees.
There is very limited experience in children between 3 and 9 years of age and no experience in children less than 3 years of age or in children and adolescents between 10 and 17 years.
There are no safety, immunogenicity or efficacy data to support interchangeability of Pandemrix™ (H1N1) with other H1N1 pandemic vaccines.
There are no data on co-administration of Pandemrix™ (H1N1) with other vaccines. It is recommended that if co-administration with another vaccine is considered, immunisation should be carried out on separate limbs and it should be noted that the adverse reactions may be intensified.
The immunological response may be diminished if the patient is undergoing immunosuppressant treatment.
Following influenza vaccination, false-positive serology test results may be obtained by the ELISA method for antibody to human immunodeficiency virus-1 (HIV-1), hepatitis C virus and, especially, HTLV-1. In such cases, the Western blot method is negative. These transitory false-positive results may be due to IgM production in response to the vaccine.
Pregnancy and lactation:
There are currently no data available on the use of Pandemrix™ (H1N1) in pregnancy. Data from pregnant women vaccinated with different inactivated non-adjuvanted seasonal vaccines do not suggest malformations or foetal or neonatal toxicity.
Animal studies with Pandemrix™ do not indicate reproductive toxicity.
The use of Pandemrix™ (H1N1) may be considered during pregnancy if this is thought to be necessary, taking into account official recommendations.
Pandemrix™ (H1N1) may be used in lactating women.
Effects on ability to drive and use machines:
Some of the undesirable effects of Pandemrix™ may affect the ability to drive or use machinery.
Clinical trials with the mock-up vaccine have evaluated the incidence of adverse reactions in approximately 5000 individuals 18 years old and above who received formulations containing A/Vietnam/1194/2004 (H5N1) strain with at least 3.75 µg HA/AS03.
Very common disorders (>=1/10) included headache; arthralgia and myalgia; induration, swelling, pain and redness at site of injection; fever and fatigue).
Common disorders (>=1/100 to <1/10) included lymphadenopathy, ecchymosis at the injection site, sweating increased;, shivering, influenza-like illness, injection site reactions (such as warmth, pruritus).
Uncommon disorders (>=1/1000 to <1/100) included insomnia; paraesthesia, somnolence and dizziness; gastrointestinal symptoms such as diarrhoea, vomiting, abdominal pain, nausea;, pruritus, rash and malaise.
A clinical study evaluated the reactogenicity in children 3-5 and 6-9 years of age who received either a full or a half dose of AS03-adjuvanted vaccine containing 3.75 μg HA derived from A/Vietnam/1194/2004 (H5N1).
The per-dose frequency of adverse reactions observed in the groups of children who received a full dose of AS03-adjuvanted vaccine containing 3.75 μg HA derived from A/Vietnam/1194/2004 (H5N1) was higher than that observed in the groups of children who received half of the dose, except for redness in the 6-9 years of age group.
From post-marketing surveillance with interpandemic trivalent vaccines, uncommon adverse reactions reported included generalised skin reactions including urticaria. Rare adverse reactions included neuralgia, convulsions and transient thrombocytopenia. Allergic reactions, in rare cases leading to shock, have been reported. Very rare adverse reactions included vasculitis with transient renal involvement and neurological disorders, such as encephalomyelitis, neuritis and Guillain Barré syndrome.
No case of overdose has been reported.
Pandemrix™ (H1N1) is contraindicated in individuals with a history of anaphylactic (i.e. life-threatening) reaction to any of the constituents of this vaccine or of any trace residues within the vaccine (egg and chicken protein, ovalbumin, formaldehyde, gentamicin sulphate and sodium deoxycholate). If vaccination is considered necessary, facilities for resuscitation should be immediately available if needed.
For full details of contraindications and possible adverse events with Pandemrix™ (H1N1) please see appropriate sections in Pandemrix™ (H1N1) Summary of Product Characteristics (SPC).
JD : Last updated October 2009 : POR/COE/1009/0078/01
Related Links & Resources
* Pandemrix™ (H1N1) Summary of Product Characteristics
* Pandemrix™ (H1N1) Patient Information Leaflet
* How To Use Pandemrix™ (H1N1) Demo