The telephones at health centres and surgeries up and down the country last week were even busier than normal. There was the usual winter fare - tonsillitis, flu, ear infections, backaches. And then there were the calls about smallpox.

It was the Richard and Judy show that did it. An item on smallpox and the risk of a terrorist biological attack, and the hysterical and hypochondriacal were on their phones, engaged in a hopeless quest to find a vaccine. I know, I was among them.

It wasn't helped by David Blunkett, who - mistakenly as it turns out - told the Commons that anyone worried about smallpox should ask their GP to inoculate them. Oh, and then there was the news that Britain has only 20 million doses of smallpox vaccine held in reserve, when in fact there are 60 million of us who might need it.

So, following Blunkett's advice it's off to the GP's surgery. The receptionist hears the word smallpox, and sighs. "This is an inner-city practice, with overworked doctors serving a deprived population with real illnesses that still exist, not imaginary ones that were wiped out decades ago," was the unspoken message.

She says, as helpfully as she can, that she will try to get a doctor to call me back. There is no response, even after a second call. Another doctor says that GPs do not keep stocks of the smallpox vaccine. But don't worry, he says; he now knows all the symptoms for smallpox, having been advised by the public health authorities to dust off his old medical books and refresh his memory about not only smallpox, but anthrax, botulism, plague and a host of other ghastly diseases that could be used in a biological attack. So he will recognise it, but cannot prevent it.

There is no more help at the vaccination centres. Not at the British Airways travel centre in Regent Street, nor the vaccination centre in Fleet Street, nor the one at Marble Arch, where callers have been begging not only for smallpox, but also anthrax jabs. "People are very worried," says a helpful woman. "But at the moment there's nothing to worry about. You won't be able to get a smallpox jab until there's actually a real threat."

A call to the public health laboratory service is referred on to the department of health, which says that four experts have been vaccinated so far.

Apparently they will go round the country vaccinating other healthcare workers in a "cascade" effect, until 350 key people are protected.

Four! And this when America, France and Germany are accruing enough stocks of vaccine for every citizen to be inoculated. It's starting to look as if we are ill-prepared. The search for a vaccine moves to America, which, with its massive population and its you-want-it-we-got-it consumer culture must be awash with the stuff.

The department for homeland security suggests contacting individual doctors and medical centres.

Dr Jeffrey Belmont in New York has none. Dolores at Georgetown University Hospital in Washington has none. "You can get them, but you can't get one here," she says tantalisingly. And at the New York office of Dr Anthony Azar, the lady answering the telephone helpfully states that smallpox was wiped out two decades ago and doctors will not vaccinate today unless there is a very good reason.

But there is a very good reason, I persist. That's why George Bush has been vaccinated. That's why he's trying to get tens of thousands of emergency workers vaccinated. That's why we're going to war. It's called terrorism.

She recommends the New York Department of Health and Mental Hygiene. There a nice man called Andrew Tucker says that smallpox vaccines are available only to health and safety workers in the city who would be the first to respond to any outbreak. It's not looking good.

I turn to the internet and type in: "Where the hell can I get a smallpox vaccination". There are zillions of items - on the slow take-up of the vaccination among emergency workers in the US; on the biotech companies rubbing their hands with glee as they respond to government demands for huge batches of previously obsolete vaccination; and on the people becoming ill after being vaccinated. But there is no sign of anyone flogging the vaccine.

For the truth, according to John Oxford, professor of virology at the Queen Mary School of Medicine in London, is that the risk of catching smallpox is "vanishingly small"; but the risks of serious side-effects and even death from the vaccination are real.

Even assuming that terrorists have got hold of the virus (which is far from certain), and an infected person wanders around in public, you would have to get pretty close to them to catch it. It wouldn't spread like wildfire, says Oxford; its progress through a community would be more akin to that of a "laggardly old-age pensioner".

The vaccination, on the other hand, is much more of a risk. "Some people will definitely die if they have this vaccine," says Professor Oxford.

Of those who are vaccinated, one in three will suffer fever and headaches sufficiently incapacitating for them to need several days off work or school.

Out of every million recipients, a thousand will suffer more serious reactions, with a high fever and sores on the genitalia, face and eyes that can cause blindness or disfigurement.

For up to 52 people per million, these side-effects will be life-threatening, causing conditions such as encephalitis and gangrene. Several patients will be left brain damaged or paralysed, and one to two per million will die.

Then there are all those people for whom the vaccine is not recommended. Of course, this might all be reassessed if you had actually been exposed to the virus. Those whose immune system is impaired; people living with HIV, Aids and cancer; those with eczema, psoriasis, acne, shingles, or chicken pox; those over 65; women who are pregnant or breastfeeding.

On that basis, three members of my family are precluded from having the vaccine. My husband and eldest son suffer from eczema, which rules them out; and I'm allergic to streptomycin, which is one of the vaccine ingredients.

Eczema is a problem because the vaccine, rather than being injected into the skin, is scratched on to the surface. With eczema, rather than staying in one place, the risk is that the virus could spread along the skin, leading to serious complications and possible death of the person vaccinated.

"I don't see why people would be interested in having a smallpox vaccination," says Professor Oxford, laconically. Me neither. My search is over. If a case is confirmed, I'll think again.

Smallpox: the facts

· In Britain, the disease was at its height in the late 17th and early 18th century, when smallpox is thought to have caused one death in six.

· One in five victims will die from the disease. The first signs of illness are a high temperature, a headache, and sometimes vomiting. A rash appears on the face a few days later, and spreads to the rest of the body, developing into fleshy circles of pus which smell of rotting flesh. On the 12th day, scabs begin to appear on the face and spread to the rest of the body. By the 14th day, they can start slowly falling off, until by the 20th day, if the victim is going to survive, the lesions have almost cleared, leaving pitted scars and, in a minority of cases, blindness in one or both eyes.

· The virus was first used as a biological weapon in 1763, when Sir Jeffrey Amherst authorised the distribution of blankets previously used by smallpox patients to American Indian tribes.

· Smallpox was the first disease against which vaccination was shown to be effective, by Edward Jenner 200 years ago.

· The last major outbreak in Britain was in 1962, when 25 people in Rhondda, south Wales contracted the virus and six died.

· The World Health Organisation declared smallpox had been formally eradicated in 1980.

· There are two WHO-approved sites where the variola virus which causes smallpox is kept; in Atlanta, Georgia, in the US, and at Novosibirsk, Russia. There are fears that terrorists could have got hold of the virus, but no leaks have ever been confirmed.

· Immunisation involves being given a live dose of the vaccinia virus, related to the variola virus, which causes smallpox. The vaccine is administered via a small scratch on the arm or thigh which is covered with a bandage. After a week to 10 days, the scratch forms a blister full of fluid containing the virus which can infect others.

· The vaccine is believed to be effective even if administered three or four days after exposure to the virus.

· Anyone over 35 is likely to have been vaccinated. Jabs were offered routinely in Britain until 1971, but full immunity lasts only three to five years.