The Sketch: A grave situation, a cautious minister and an unenviable decision

There may be a new directive out from Labour Central, for ministers to speak more slowly. John Reid is saying less than he used to and taking longer to do so. The gravity of his statement on vCJD and blood safety yesterday concealed that propensity, so his announcement received less scrutiny than it deserved.

It was revealed late last year that one poor individual had contracted the horrible variant Creutzfeld Jacob disease from a blood transfusion. The odds of that happening are vanishingly small, and God knows, one would pray, if one thought it would help. Mr Reid told us the patient had received blood from an existing sufferer, or carrier of the disease and then developed it in turn. Fifteen other patients received blood from disease sufferers - none of the 15 has developed the disease.

Thus, the minister's very proper concern is there are donors who may be vCJD carriers and who may be giving bad blood. Who they are is impossible to know, and the risk they pose is impossible to quantify.

Very little is known about the transmission of this disease nor its incubation rate. But the proposition of risk is this: anyone who has received blood since 1980 might have received it from a carrier, they might be capable of passing it on and the people receiving it might become infected and might subsequently develop the disease themselves.

How many vCJD cases are there in Britain? Mr Reid didn't say. Andrew Lansley put it at 146. How many of those sufferers gave blood since 1980? Mr Reid didn't say (but then he wasn't asked).

The solution the Department of Health has accepted is to exclude anyone who has had a blood transfusion since 1980. Mr Reid calls it a "precautionary approach". As 800,000 people a year give blood and three million blood components are distributed, we can start to gauge something of the size of the precaution.

It's a judgement call, and an unenviable one. Reasonable people can agree or disagree with it. One case in five million transfusions has had an appalling result since 1996, and now 52,000 donors will be excluded from the essential service.

That's about 7 per cent of the total, and here lies the part that needed a little more scrutiny.

As there is only one week's supply of blood kept in the bank, how can we be sure that blood stocks won't be 7 per cent down come implementation date in three weeks' time? To see the Government do anything quickly is like watching a car crash in slow motion.

The risk of vCJD infection is unquantifiable, the risk of running out of blood, on yesterday's evidence, is more proximate. So here we are. This is where trust in government really does become significant.