by Lois Rogers and Bryan Christie
THE government is preparing to warn doctors that British blood products, including vaccines given to children, could be at risk of contamination from CJD, the human form of "mad cow" disease.A letter being drafted by Ken Calman, the chief medical officer, will reveal that scientific advisers to a European medical committee meeting this week have concluded that all products derived from British blood - including vaccines - could transmit the disease.
British experts on CJD are anxious to emphasise that the life-saving benefits of blood transfusions and vaccinations against killer diseases far outweigh the risk of CJD, which is believed to be minimal.
However, the newly identified form of beef-related CJD can theoretically pass from person to person and could be more infectious than "classic" CJD.
The expert report will be presented to a meeting of the Committee on Proprietary Medicinal Products (CPMP), a pan-European advisory body, on the safety of medical products when it meets this week.
Europe may impose a ban on the export of British blood and blood-derived protein called albumin prepared from donor plasma, which is used in pharmaceutical products including vaccines. This could provoke a political outcry. Noel Wadhion, the committee's spokesman, said no formal response would be made by the CPMP until the end of the week.
The principal vaccine containing human serum albumin is for measles, mumps and rubella (MMR), and is received by millions of children. British supplies are produced in America which has no cases of the new variant of CJD. However, British albumin is used in other vaccines and exported to vaccine manufacturers elsewhere.
Calman said blood collected here has a safety record second to none in terms of risk of transmitting hepatitis, HIV or other viruses. "We don't know that the theoretical risk of CJD transmission is from blood, if it's there at all," he said. "The letter to doctors isn't finalised.
"We have discussed the consequences of this report, but it depends on the final statements from the European committee and advice from the Committee on Safety of Medicines here. To get a blood product from another country which has a high risk of some other infection doesn't seem a particularly good idea to me."
Calman's letter will guide doctors on how to explain to patients what is known so far about the risk from new-variant Creutzfeldt-Jakob disease (nvCJD) which, it is emphasised, is far outweighed by the dangers of not having the treatment.
Ministers believe the public should be informed of any risk of BSE infection, however slight - as they were over beef on the bone, banned from sale in December. So far there have only been 23 confirmed cases of the so-called nvCJD. However, scientists think there are many more undiagnosed victims. A World Health Organisation (WHO) meeting two weeks ago concluded the possibility of a "significant nvCJD epidemic" in 10 years can no longer be ignored.
Martin Ziedler, an adviser on the disease at the WHO, said calculations a year ago, when there were just 14 confirmed cases of nvCJD, indicated there could be up to 80,000 more British victims. Now it is impossible to predict the possible scale of any epidemic.