2009 H1N1 Flu (Swine Flu) & the Safety of Plasma-Derived Products
At CSL Behring, the health and safety of those who rely on our products is our most important priority. Understandably, the H1N1 influenza virus is prompting questions about the spread of infection through various means. Individuals who use plasma-derived therapies can rest assured that these therapies remain safe and do not pose a risk of infection by swine-origin Influenza A (H1N1).
CSL Behring has a number of measures in place designed to ensure the safety of our therapies.
For example, the health status of plasma donors is checked before each donation. Donors who exhibit symptoms of illness or who have an elevated body temperature are deferred, thus minimizing the chances of influenza virus even entering the plasma pool. Furthermore, the standard processes used in manufacturing all CSL Behring plasma-derived products include methods for inactivating and/or removing potentially present influenza viruses. These processes include heat inactivation and filtration, and we have gathered strong evidence on the effectiveness of these steps in inactivating or removing viruses such as influenza.
CSL Behring performs virus validation studies to ensure that an appropriate margin of safety regarding blood-borne viruses is established in each product lot. These studies employ a wide range of different viruses, and thus provide evidence that the production processes do, indeed, inactivate and/or remove novel virus contaminations, in addition to known viruses. Experiments performed in CSL Behring virology laboratories have demonstrated that different influenza virus strains are very effectively inactivated by heat treatment in aqueous solution. Influenza viruses are enveloped viruses with a size of approximately 80 to 120 nm in diameter. Virus filtration with dedicated virus filters effectively removes influenza viruses. Effective removal has been demonstrated for viruses smaller in size than H1N1 in virus validation studies. CSL uses heat treatment and/or virus filtration in the manufacture of all CSL Behring products.
The risk of plasma-derived products transmitting any type of influenza virus is virtually non-existent. Indeed, according to the
U.S. Food and Drug Administration's recent statement on this matter, "No case of transfusion transmitted seasonal influenza has ever been reported in the United States or elsewhere, and, to date, no cases of transfusion transmitted H1N1 flu have been reported."