A little knowledge: How research scientists were caught out by swine flu

Why was the swine flu pandemic so much milder than expected? The truth is that research scientists were caught out by this mysterious virus, writes Jeremy Laurance

(LEWIS WHYLD / AFP / GETTY IMAGES)

At a drinks reception shortly after Christmas, I was goaded by a senior member of the British Medical Association. "I hear you have become a swine flu denier," he said. I put him right: I have become a swine flu sceptic, I said. Then he – a GP – admitted he had not had the vaccine. Along with two-thirds of frontline health workers, he had declined the advice to get protected.

This week, Dame Deirdre Hine, who is conducting an independent review into the Government's response to the swine flu pandemic, will take evidence from journalists, including myself. She will seek to understand why senior doctors like the BMA member_ rejected the vaccine, and what lessons can be learned for future pandemics. One question she will need to address is whether the swine flu outbreak deserved the term "pandemic".

The way a disease is portrayed matters. I was struck by this – in retrospect – when I went to Hong Kong in March 2003 during the Sars (Severe Acute Respiratory Syndrome) outbreak. I arrived a couple of days before the World Health Organisation declared a no-go area, banning all but essential travel to Hong Kong. It was already known that Sars was relatively difficult to catch – not like flu at all. Despite this, Hong Kong was gripped by fear – numbers on the streets dwindled visibly in my week there. I took a taxi to Amoy Gardens, a high-rise housing estate where dozens had been infected, and the driver dropped me 200 yards short – he wouldn't go any closer.

My most vivid meeting was with the intensive-care specialist, Tom Buckley, at the deserted 1,300 bed Prince of Wales hospital just outside the city. He insisted I conduct the interview with him sitting outside on a bench six feet apart in the open air, each of us with masks on. He had seen 100 of his medical colleagues go down with the illness, so his caution was understandable. But the next day I took the train to the city of Guangzhou, so-called ground zero of the outbreak. In Hong Kong, 80 to 90 per cent of people on the streets were wearing masks. In Guangzhou I counted just four all day. I briefly met the British consul general who described the reaction in Hong Kong as "hysterical", but admitted there had been something of an "information vacuum" in his own city.

One city saw it one way, another saw it differently. Can the media be held solely responsible for the difference? It wasn't the newspapers who banned travel to Hong Kong, it was the WHO. And it was the information vacuum in Guangzhou that allowed Sars to escape to Hong Kong and the rest of the world. Yet the media – in Hong Kong and the UK – were later accused of over-reacting.

It is noteworthy that, in the aftermath of the 2009-2010 swine flu pandemic, it is governments rather than the media that are coming under scrutiny. There is a blizzard of inquiries, the World Health Organisation has been accused of crying wolf, and the Council of Europe is worried about the influence of the pharmaceutical industry.

National policy is to prepare for the worst and hope for the best. That is indubitably right. Sir Liam Donaldson, the UK's chief medical officer, deserves much of the credit for Britain's highly praised state of preparedness. Sir Liam's weekly press briefings were models of clarity: restrained, strictly factual, eschewing speculation. There was a real effort at transparency and it was rewarded by reporting that was, for the most part, accurate and proportionate.

But a briefing – and indeed a pandemic plan – can only be as good as the information on which it is based. One thing that the swine flu pandemic has exposed is the depths of our ignorance about the flu virus. Despite 50 years of study, we still know remarkably little about why it behaves in the way it does. Why did it flare up in summer? Why was Britain so hard hit? Why did it come from the west (Mexico) and not, as expected, from the east? To all these questions, scientists and public health specialists responded with a regretful shake of the head. Perhaps it would have been better to emphasise how little we knew about the virus rather than how much we had prepared.

Without doubt, fear of avian flu shaped the world's response to swine flu. Avian flu emerged more than a decade ago in the Far East and in 2004 began its march across the globe, infecting poultry flocks, wild birds and the occasional person as it went. With 495 people infected so far and 292 deaths, its 60 per cent death rate posed a serious threat. Swine flu has – mercifully – proved to be a kitten, not a tiger. Will it turn out to be the weakest pandemic in history? It is too early to say; it could yet return with a vengeance next winter. But there are some questions to ask now.

Up to 15 April there had been 474 deaths from swine flu, compared with 2,000 to 4,000 from seasonal flu in an average year and up to 20,000 in a bad one. Yes, swine flu is different – it targets younger people (most deaths have occurred in the 15-44 age group), and seasonal flu targets the elderly. But seasonal flu was driven out last winter by the "novel H1N1 pandemic" virus. So pandemic flu may end up, bizarrely, having saved lives overall from flu in the 2009-2010 season.

Early in the pandemic, the Department of Health said its "worst-case scenario" was up to 65,000 deaths. That figure was revised down to 1,000 deaths in the autumn, as the virus turned out to be milder and to have spread further than had been thought.

Was use of the term pandemic appropriate? Before swine flu broke out, the WHO was preparing for a future pandemic that would kill four times as many people as non-pandemic influenza. In the UK, the Department of Health wrote, before swine flu emerged, that "we can assume [that the next pandemic] will be of greater magnitude than even the most severe epidemic of 'ordinary' flu."

It is only since swine flu turned out to be mild that the term "pandemic" has been separated from "severity". In May last year, days after the emergence of swine flu, the WHO removed the phrase "enormous numbers of deaths and illness" from its definition of a pandemic, saying that high mortality was not an inevitable, but rather an exceptional, quality of a pandemic.

There is, then, a legitimate question about use of the term "pandemic", and it is disingenuous to argue, as some do, that it was simply a problem of "risk communication". Even the name of the virus "Novel H1N1 influenza" is puzzling. How was it that a "novel" virus turned out on closer inspection not to be so novel after all?

We were told that though it was mild because it was novel, it could spread widely and kill a lot of people by virtue of the sheer numbers infected. Later it emerged that people over 50 had some immunity. Although the virus itself was novel, its surface antigens had some similarities to those on H1N1 viruses circulating up to the 1960s. Could this have been spotted sooner?

At a briefing last month Professor Neil Ferguson, of Imperial College, London said assessments of the pandemic in the early months were broadly accurate. But he added: "The difficult thing was tracking how many people were being infected. That was critical to tell how severe the virus was. We saw some people dying but we couldn't put those numbers in perspective." The uncertainty led to predictions that the autumn wave of infections could be up to three times greater than the summer wave. In fact the autumn wave turned out to be about the same size. "The challenge," said Professor Ferguson, is to develop more rapid diagnosis to overcome the problem of tracking the pandemic. Had we known what we were getting, we would have responded at a lower level."

So there are lessons to be learned. But it is easy to be wise after the event. As Professor Robert Dingwall, of the University of Nottingham, put it at the same briefing, "Governments are damned if they act and damned if they don't."

The flu virus is capricious, the disease elusive, and our remedies imperfect. Far better to be prepared before it than repent after. But every £1bn spent protecting us from swine flu is £1bn not available for other health needs. Could the virologists have given us a clearer idea, sooner, of the true scale of the threat?