The oral polio vaccine, opv, to which the Deputy refers was manufactured by Evans-Medeva in the UK and distributed for use in Ireland during the period 15 January 1998 to 30 January 1999. Seven batches of the vaccine consisting of 95,890 units were available for use over this period. On 13 December 2000 the Irish Medicines Board informed my Department that a constituent of the vaccine, namely, human serum albumin, HSA, utilised a blood donation in its manufacture from a UK resident who has recently been diagnosed as having the variant form of Creutzfeldt Jakob Disease, vCJD.
HSA is a product which is made from human blood donations. It is a protein, albumin, obtained from blood serum, hence its name. It is used as a stabiliser in some medicinal products and vaccines. On receipt of the information relating to this vaccine from the IMB, I arranged to obtain expert advice from national and international experts in the field who advised on a wide range of aspects relating to this issue. Their advice indicated that the potential risk, if any, to recipients is essentially non-existent.
This expert advice is based on a number of factors: the dilution factor involved in this case – the persons donation was one of 22,353 used to make a pool. This is turn was combined with another pool to give a final dilution of 1-63,866; the manufacturing process by which albumin – the agent used to stabilise the vaccine – is made from plasma involves a number of stages in the course of which any potential infectivity would be removed – in other words, no infectivity has been associated with albumin; the fact that polio vaccine is administered orally rather than by injection further reduces the theoretical possibility of transmission.
The plasma donation involved in this incident was donated in 1996-97 and the individual concerned has only recently been diagnosed as having contracted the disease. It would not therefore have been possible at the time of this person's donation to "screen it out" on the basis that he or she might later develop CJD. While blood donations are screened for communicable diseases there are no tests which would enable donations to be screened for CJD or vCJD or which would allow doctors to establish whether an individual is at risk of contracting these diseases.