The first doses of influenza A (H1N1) vaccine could be available within five to six months after identification of the new virus. Prior to this date, small quantities of experimental vaccine will be made available to immunize volunteers in clinical trials to select the best vaccine formulations. Regulatory approval for the vaccines will be conducted by national authorities in parallel with the manufacturing process. National regulatory authorities have put into place expedited processes that do not compromise on the quality and safety of the vaccine. Delays in production could result from poor growth of the virus strain used to make the vaccine.
There are currently more than a dozen influenza vaccine manufacturers with licenses to produce vaccines. Upon request, the vaccine strain will be made available to each of them, as well as to other qualified vaccine manufacturers who are preparing to make influenza A (H1N1) vaccine, but do not yet have a licensed seasonal influenza vaccine.
Projections made for the production capacity of a vaccine for H5N1 cannot be automatically assumed to be the same for an H1N1 vaccine. H5N1 and H1N1 are distinct viruses, so the amount of antigen needed to make an effective H1N1 vaccine may differ from that for H5N1. Therefore, it is not possible to make a precise estimate. However, notwithstanding these considerations, and based on a global survey made by WHO on May 15, 2009, a maximum 4.9 billion could be produced in 12 months. This would only be the case if a number of conditions are met— notably that production yields for influenza A (H1N1) vaccine are equivalent to those usually obtained for seasonal vaccines, and that manufacturers use the vaccine formulation which has been shown for H5N1 influenza as being the most “dose-sparing” (i.e. those which use the smaller quantity of active principle). A more conservative estimate of global capacity is at least 1 to 2 billion doses per year. This does not translate automatically into numbers of persons vaccinated, as we do not yet know how many doses of the vaccine will be needed to achieve protection.
Close to 90% of the global capacity today is located in Europe and North America, with further significant manufacturing capacity in Australia and Japan. However, during the past five years, six manufacturers in developing countries have begun to acquire the technology to produce influenza vaccines and have received technical and financial support from WHO.
If you would like to make a comment, please fill out the form below.
Featured Reports
