Influenza A H1N1 Monovalent Vaccine
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Influenza A H1N1 Monovalent Vaccine
Sanofi Pasteur's Influenza A (H1N1) 2009 Monovalent Vaccine and seasonal trivalent Influenza Virus Vaccine (Fluzone®) are manufactured by the same process. The following sub-sections summarize safety data from clinical experience with seasonal trivalent inactivated influenza vaccines, including Fluzone vaccine.
Clinical Trial Experience
Adverse event information from clinical trials provides the basis for identifying adverse events that appear to be related to vaccine use and for approximating the rates of these events. However, because clinical trials are conducted under widely varying conditions, adverse event rates observed in the clinical trials of a vaccine cannot be directly compared to rates in the clinical trial of another vaccine, and may not reflect the rates observed in practice.
Adults and Geriatrics
In placebo-controlled studies among adults, the most frequent side effect of vaccination is soreness at the vaccination site (affecting 10%–64% of patients) that lasts < 2 days, local pain and swelling. These local reactions typically are mild. Fever, malaise, myalgia, and other systemic symptoms can occur following vaccination and most often affect persons who have had no prior exposure to the influenza virus antigens in the vaccine (e.g., young children). These reactions begin 6–12 hours after vaccination and can persist for 1–2 days. Placebo-controlled trials demonstrate that among older persons and healthy young adults, administration of split-virus influenza vaccine is not associated with higher rates of systemic symptoms (e.g., fever, malaise, myalgia, and headache) when compared with placebo injections. (2)
The 2003-2004 formulation of Fluzone vaccine was studied in 19 children 6 to 23 months of age and in 12 children 24 to 36 months of age, given in 2 doses one month apart. Local reactions and systemic events were solicited for 3 days after each dose. Most local and systemic reactions were mild. The proportions of local and systemic reactions in children were similar to the proportions in adults. No reported local or systemic reaction required a therapeutic intervention other than analgesics. (3)
The following additional events have been reported during post-approval use of Fluzone vaccine. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to vaccine exposure.
Nervous System Disorders: GBS, convulsions, myelitis (including encephalomyelitis and transverse myelitis), facial palsy (Bell's palsy), optic neuritis/neuropathy, brachial neuritis, syncope (shortly after vaccination), dizziness, paresthesia
Vascular Disorders: Vasculitis, vasodilation/flushing
Skin and Subcutaneous Tissue Disorders: Stevens-Johnson syndrome
General Disorders and Administration Site Conditions: Fever, pain, pruritis, asthenia/fatigue, pain in extremities, chest pain
Other Adverse Events Associated with Influenza Vaccines
Anaphylaxis has been reported after administration of influenza vaccines. Although Influenza A (H1N1) 2009 Monovalent Vaccine contains only a limited quantity of egg protein, this protein can induce immediate hypersensitivity reactions among persons who have severe egg allergy. Allergic reactions include hives, angioedema, allergic asthma, and systemic anaphylaxis. [See CONTRAINDICATIONS]
The 1976 swine influenza vaccine was associated with an increased frequency of Guillain-Barré syndrome (GBS). Evidence for a causal relation of GBS with subsequent vaccines prepared from other influenza viruses is unclear. If influenza vaccine does pose a risk, it is probably slightly more than 1 additional case/1 million persons vaccinated.
Neurological disorders temporally associated with influenza vaccination such as encephalopathy, optic neuritis/neuropathy, partial facial paralysis, and brachial plexus neuropathy have been reported.
Microscopic polyangitis (vasculitis) has been reported temporally associated with influenza vaccination.
Read the Influenza A H1N1 Monovalent Vaccine (influenza a h1n1 monovalent vaccine) Side Effects Center for a complete guide to possible side effects
Concomitant Administration with Other Vaccines
There are no data on the concomitant administration of Influenza A (H1N1) 2009 Monovalent Vaccine with seasonal trivalent influenza vaccines.
Influenza A (H1N1) 2009 Monovalent Vaccine should not be mixed with any other vaccine in the same syringe or vial.
If Influenza A (H1N1) 2009 Monovalent Vaccine is to be given at the same time as another injectable vaccine(s), the vaccine(s) should always be administered at different injection sites.
If Influenza A (H1N1) 2009 Monovalent Vaccine is administered to immunosuppressed persons or persons receiving immunosuppressive therapy, immunologic response may be diminished.
Last reviewed on RxList: 11/5/2009
This monograph has been modified to include the generic and brand name in many instances.
Additional Influenza A H1N1 Monovalent Vaccine Information
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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