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The Daily Hampshire Gazette
The bird flu threat, Putting panic into perspective
Originally published on: Tuesday, May 30, 2006
BY SUZANNE WILSON, STAFF WRITER

TO hear Dr. William Swiggard talk, you would think there was nothing on earth more interesting than viruses.

They are utterly, utterly fascinating, says Swiggard, a doctor in Northampton who specializes in infectious diseases.

Ever since he studied immunology at The Rockefeller University in New York City, Swiggard has been intrigued by influenza viruses – how they form and mutate, how they attack the body, and how medicine and science have tried to combat them.

‘They’re astoundingly smart,’ he says.

Under the microscope, Swiggard says, an influenza virus is roundish in shape, with two types of protruding spikes, plus some surface bumps. ‘They look like a space capsule with these spikes sticking out of the outside,’ he says.

Those spikes and bumps all play roles in the process of binding the virus to the host cells – in your body, for instance – and delivering what he calls their ‘genetic payload’ into the cells. In simplest terms, as Swiggard explains it, that payload carries a message that says: Make more of me, and here’s how!

The pandemic of 1918

When he arrived at the Gazette for an interview last week about the avian influenza virus – known informally as the bird flu virus – Swiggard brought with him a thick stack of articles from medical journals and a copy of John M. Barry’s 2004 book, ‘The Great Influenza: The Epic Story of the Deadliest Plague in History.’

Barry’s book is about the flu pandemic of 1918, a calamity that claimed at least 40 million deaths worldwide in less than a year. (Smaller-scale flu pandemics also occurred in 1957 and 1968.)

Though most influenza viruses occur in wild or domestic birds, it’s not known exactly how the 1918 virus evolved. The current thinking, Swiggard said, is that the virus probably started in ducks and then somehow jumped the species barrier to humans. Unlike most influenza viruses, it apparently accomplished that feat, Swiggard said, without mixing with genes from a previously existing human virus strain.

Of the millions who died in 1918, Swiggard said, many were young, previously healthy adults between the ages of 18 and 40, and children. And many, as Barry’s book recounts, died terrible deaths, suffering from fevers, aches, delirium, bleeding and suffocating chest congestion.

Since then, scientists have established that influenza is caused by viruses, and have learned how to develop vaccines to prevent it. Today, millions of Americans line up annually for flu shots – vaccines developed each year to counteract the particular strain of virus that is currently circulating.
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Enter H5N1

Now there is fear of H5N1, the official name of a lethal subtype of bird flu that first infected humans in Hong Kong in 1997. It is the most deadly of a large family of bird flu viruses, most of which produce only minor illnesses in birds – and may, some experts say, be more virulent than the 1918 virus.

In an effort to control the spread of H5N1, thousands of birds in Asia have been slaughtered; some flocks have been successfully vaccinated.

Deaths in humans – 124 to date, in Vietnam, Thailand, Cambodia, China, Iraq, Indonesia, and parts of Africa and Europe, according to the World Health Organization – have occurred mostly in people who live close to flocks of chickens they tend.

It’s important to understand, Swiggard points out, that H5N1 has not yet mutated in such a way as to make the leap to easy human-to-human transmission – and it may never do that. If and when it arrives in North America, Swiggard said, it’s possible that it will affect only poultry: ‘I think that is actually the most likely scenario.’

That could certainly change, however – and quickly. Late last week, the WHO said it is investigating the deaths of six members of a family in Indonesia who died after coming down with the flu.

The concern is that the case appears to be the first in which the virus made a three-person jump, from one person to another to another.

The WHO said, however, that the family members may have died because they lived with each other in close quarters – not because the virus has managed to mutate in such a way as to make transmission easy and efficient.

Some perspective

To keep the threat posed by H5N1 in perspective, Swiggard also emphasizes that the number of human deaths to date, 124, is tiny compared with this number: 36,000.

That’s the number of Americans who die every year from the flu; the worldwide toll is close to 500,000.

‘And yet that is not headline news,’ Swiggard said, ‘but it needs to be. The thing that we often forget is the scope of the problem right now.’

It rankles him, Swiggard said, that some Americans, even those in high-risk groups, such as the elderly or those with chronic illnesses, don’t get flu shots because they believe the shot itself will make them sick.

‘It’s one of the greatest ways to make me shriek with pain,’ Swiggard said, only half-jokingly, of his reaction to fears that flu shots either don’t work or are harmful.

‘You might get a fever, but that is the sign of a healthy immune system response [to the vaccine],’ he said. ‘It’s not the same as real influenza that makes you dreadfully ill.’

Scary virus

Which is not to say, Swiggard hastens to add, that we should be complacent about H5N1.

‘This virus has the scariest properties we’ve seen in many, many years,’ he said.

For one thing, its mortality rate is about 50 percent – much higher than that of any flu strain in recent years. And, like the virus of 1918, H5N1 has claimed victims among otherwise healthy young adults.

Second, some of the anti-viral drugs that have been effective against other viruses in the past are either ‘completely useless’ against H5N1, or may prove to be.

It is worrisome, Swiggard said, that H5N1 is showing signs of developing resistance in some cases to Tamiflu, a widely used antiviral drug. Tamiflu, for example, is the drug that is being given on a preventative basis to villagers in Indonesia who had had contact with members of the family that died last week.

Besides concerns about its effectiveness, there’s another big problem with Tamiflu, Swiggard said: supply. There simply isn’t enough of it to go around, should a pandemic occur.

‘So Tamiflu is clearly not a magic bullet or a panacea.’

The magic lamp

The development of a vaccine, says Swiggard, is the best bet against bird flu. ‘If I could rub the magic lamp and ask for any medicine to protect myself, it would be a vaccine.’

On that front, however, Swiggard said that while research is well under way at different sites around the world, there is still plenty of work ahead.

‘We know how to make a vaccine, and some preliminary vaccines are in clinical trials.’ But there are still questions, he said, about exactly which components will need to be included in the vaccine for it to be effective.

Moreover, to be safe, vaccines must be manufactured with great care, he said – which has not always happened. In 2004, he noted, a batch of vaccines in England had to be destroyed when the factory they were developed in failed to meet proper sterility levels.

In this country, Swiggard noted, a March 2006 report in the New England Journal of Medicine found that a vaccine being tested appeared to be safe but two strong doses were required for effectiveness omaking it an impractical solution.

‘You want to give people one dose and let that be it,’ he said.

Timing is also a question mark. No one knows, as outlined in a May 2005 report in the New England Journal of Medicine, whether a pandemic is imminent, or 10 years away.

‘NIH is concentrating very hard on a vaccine, but no one is willing to say it’ll be six months, or eight months, or longer, because there’s too much uncertainty.’ With luck and a lot of hard work, Swiggard said, the process of testing and mass-producing an effective vaccine could be accomplished in less than a year.

Swiggard said he would also like to see more U.S. drug companies get back in the business of developing and making vaccines – for many diseases. Because vaccine work isn’t always lucrative, many companies have stopped doing it, he said: ‘This is so wrong.’

Whatever the outcome of the work on a vaccine, Swiggard said common-sense measures to control the spread of infection will play a crucial role, should H5N1 arrive.

Patients with the virus will have to be quarantined, he said; protective masks will be needed. And everyone will have to be vigilant about the simple practices that help protect against any flu virus: frequent hand washing and covering the mouth when coughing.

If H5NI does arrive in this country, the May 2005 NEJM piece cited above, estimated the possible number of deaths in the U.S. at 1.7 million, and 180 million to 360 million globally.

No one knows how long the pandemic would last, or, adds Swiggard, what would make it end.

History has shown us, he said, ‘that most pandemics come to a natural end when they just disappear, and we don’t know why. It’s still a mystery – one of the greatest mysteries in medicine.’

Suzanne Wilson can be reached at swilson@gazettenet.com.