Thursday, August 27, 2009

The French were not impressed with MF59

The French performed a meta-analysis of the effectiveness and safety of flu vaccines containing MF59 for elderly recipients. Local and systemic adverse reactions were higher with vaccines containing MF59, but mortality rates were unimproved. Here is the abstract:

Prescrire Int. 2004 Dec;13(74):206-8.

Influenza vaccine with squalene adjuvant: new preparation. No better than available products.

[No authors listed]
(1) Injectable influenza vaccines reduce morbidity and mortality in people over 65 years. (2) A new influenza vaccine, with an adjuvant (MF59 C.1) based on squalene, is now marketed in France for people over 65, and especially those with chronic conditions at risk of influenza complications. (3) The clinical evaluation dossier contains data from about twenty immunogenicity studies in more than 4000 elderly subjects. According to a meta-analysis of these studies, there is no firm evidence that the MF59 C.1 adjuvant vaccine is any better than other vaccines at inducing immunity in elderly people with chronic conditions. (4) A retrospective analysis of mortality among subjects enrolled in immunogenicity studies showed no significant difference between groups receiving the squalene adjuvant vaccine and groups receiving another influenza vaccine, either in the general population or in subsets of patients with relevant chronic conditions. (5) Local adverse effects (pain, rash, induration) and systemic adverse effects (malaise, myalgia, headache) were significantly more common after the squalene adjuvant vaccine than after other influenza vaccines. Pharmacovigilance data collected by the company show no unexpected adverse events. (6) In practice, there is no reason to prefer the squalene adjuvant vaccine to existing vaccines for elderly people, whether or not they have underlying chronic conditions.
UPDATE SEPT. 13:  The package insert for the vaccine discussed in the review above, Fluad, notes that Guillain Barre Syndrome, vasculitis with transient renal involvement, encephalomyelitis and neuritis occur as rare side effects (<1/10,000). Side effects that are less rare include neuralgia, convulsions, transient thrombocytopenia, and anaphylactic reactions (<1/1000,  >1/10,000).

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