Tireless Nobelist turning his attention to the stars

Baruch Blumberg's past work is saving millions of lives. Now, aged 74, he is leading a Nasa team into the future, writes Geoff Watts

By age 74, most academics have quit the business. But not Baruch Blumberg. Seventy-four was the age at which he began a new job. And a futuristic one at that: director of the Astrobiology Institute set up in 1998 by Nasa, the US National Aeronautics and Space Administration.

Per ardua ad astra , you might say - the ardua in Blumberg's long and extraordinary career having encompassed the hunt for the cause of hepatitis B, the development of a vaccine against it, and a Nobel prize for his efforts.

An unstuffy and engaging man who in build, manner, speech and appearance bears more than a passing resemblance to television's Lou Grant, Blumberg is happy to talk at length about his science. When I met him he was en route from his temporary base in Oxford to Channel 4, where his son-in-law, Mark Thompson, recently took over as chief executive. Blumberg's links with Britain are not solely academic.

He sees basic research in science - and, by implication, his own career - as what he likes to call a "Shandean" process. The term comes from Laurence Sterne's Tristram Shandy , a novel in which narrative order is subordinated to the free associations generated by the narrator and his characters. In Blumberg's just-published account of his hepatitis B research, he expands on the point. "Events ramble from one apparent irrelevancy to another, but a strange sense of order nevertheless emerges. Accounts of scientific research are often presented in non-Shandean form, suggesting the process was planned in advance to follow a logical and ordered sequence from a body of known knowledge to a target that had been defined at the initiation of the project."

In reality, of course, most science is highly Shandean. And the hunt for the hepatitis B virus (HBV) was no exception - not least because neither Blumberg nor his colleagues set out with any such aim in mind.

His original interest was in inherited biochemical differences. "I'd seen in my early medical experience that there are big variations in the way people react when exposed to disease-causing agents. Some don't get sick; others get very sick and die. This got hammered home when I was working in Surinam as a medical student more than 50 years ago. I was in an isolated mining town in the interior. There were different populations of workers: Indonesians, Africans and Chinese as well as a few Europeans. And there was a lot of infectious disease including filariasis, elephantiasis and malaria."

Intrigued by the differing susceptibilities in and between these populations, he began to study the blood proteins of the workforce, hoping to find that differences in their biochemistry could be related to differences in their disease susceptibility. "And that's exactly what we did find," he recalls.

It was a study of this kind, in the mid-1960s, that led him to a protein associated with hepatitis B - "serum hepatitis" as it was then known. He dubbed the protein "Australia antigen" because the first positive finding was in an Australian, and antigen is a catch-all term for anything that can provoke an immune response.

It soon became clear that the Australia antigen was a protein that forms part of HBV's outer coat - though the isolation of the virus itself did not come until later. The work led first to a simple blood test, so making it possible to prevent the transmission of hepatitis during blood transfusion, and later to a vaccine against the disease.

Although HBV has much in common with HIV - both can pass during intercourse, or from mother to child, or via contaminated blood - HIV has captured the biggest headlines. Blumberg attributes this to the fact that most people appear to recover from HBV, although it is now known that they may become carriers and go on to develop chronic liver disease or one of the world's big killers, liver cancer.

Vaccination programmes against HBV have been in place for some 20 years, especially in areas such as China where the prevalence of the virus is high. The success of vaccination is obviously a source of deep satisfaction to Blumberg. He has just returned from China to assess the effect of the vaccination programme. He found that in the south, where about 16 per cent of the population were infected, prevalence had dropped to 1 per cent as a result of vaccination. In several places, research has been done on liver cancer rates and it has shown that cases have fallen by about two-thirds. If progress of this magnitude is seen elsewhere, it may be possible to claim that one of the world's common cancers can be prevented by a vaccine.

Blumberg's ties with Oxford date back to 1955, when he became a graduate student in the biochemistry department, and a member of Balliol College. They reached a high point in his mid-1960s when he was asked to stand as a candidate for the mastership of his old college. "It surprised me," he admits. "But as soon as they asked me I knew I'd do it. We had a wonderful time. It was like living on another planet compared to American academic life."

He saw British science at that time as "more of an intellectual game" than it was in the US, where the emphasis is more on action than on knowledge for its own sake. "I have a very practical background. When you're trained in medicine, you're always thinking about what the applications are. In Oxford, I could divorce myself from this for a while and just seek answers, because humans like to understand things."

After his five years at Balliol, he returned to the US to do some undergraduate teaching at Stanford University. Then came the offer from Nasa. Paradoxically, Blumberg sees age as having some advantages in this most futuristic of jobs. "We've had to delay our Mars missions because there were two failures a couple of years ago. Most people kind of regret it because they fear they're not going to live to see them. But I wasn't going to live to see them anyhow. So the fact that they're going to be delayed a few more years doesn't make much difference to me.

"Much of the work we're doing is setting up hypotheses. Our children and our grandchildren will be the ones to get the data to test them. So this is a strange kind of science in which you know you're starting an experiment that somebody else is going to finish."

Hepatitis B : The Hunt for a Killer Virus is published by Princeton University Press, £19.95.