Fly Away Home
It’s time to think about the unthinkable: a worldwide epidemic of H5N1.
H5N1 – also known as A(H5N1) – is just one strain of the avian influenza virus. But it’s a particularly deadly strain, and it’s the one that has health officials on the edge of their seats.
This virus has been with us for a long time. It was first identified in 1961 among birds in South Africa, but it took more than 35 years for a human case to emerge. Today, more than 100 cases have been attributed to H5N1 and about half have resulted in death. All of these cases are believed to be the result of transmission from infected birds. In other words, there is no evidence yet of human-to-human transmission.
If that moment should ever arrive, the confirmation that a patient with H5N1 has contaminated another person will likely be one of the defining moments of the 21st Century.
That’s the bad news. But there is some potentially good news. It’s not much, frankly, but with any luck it may be enough.
A glass half full
I had a little bird
Its name was Enza
I opened the window
And in-flu-enza
Children once sang that rhyme while skipping rope, according to a history of the Spanish Flu pandemic of 1918 and ’19. Perhaps as many as 40 million people died from that outbreak, and some estimates put the number many millions higher.
For the remainder of the 20th Century, and now in the 21st, public health officials worldwide have been on close watch, hoping to catch the next pandemic in its earliest stages. Margaret Chan – the director for pandemic influenza preparedness for the World Health Organization (WHO) – believes we may now be on the verge of such an outbreak. Before that can happen, however, H5N1 would have to mutate and mix with a human flu to create a new strain.
The warning signs are ominous: Throughout Asia and Russia, millions of birds have died from H5N1 infection, and human cases have been reported in China, Thailand, Vietnam, Cambodia and most recently in Indonesia. In an interview with Reuters Health, Ms. Chan said that WHO officials have placed the current risk assessment of a global pandemic at three on a scale of six.
This is one case where perceiving the glass as half full doesn’t inspire much optimism.
Something completely different
Amid these dire warning signs, some promising news appeared in the New York Times last week.
Anthony S. Fauci, M.D. – the director of the National Institute of Allergy and Infectious Diseases – told the Times: “It’s good news. We have a vaccine.” As the Times put it, the vaccine has been “successfully tested,” and officials “believe” it offers protection against H5N1. That’s a pretty thin reassurance to pin the hopes of the world on, but right now it’s all we have.
The vaccine is set to undergo further tests, and it still has to be licensed before it can be mass produced, but if this is the real thing, and if enough of it can be produced before risk assessment climbs higher on the scale of six, then we may eventually have a way to defend ourselves against a full blown pandemic. But those are two very big “ifs.”
In past e-Alerts I’ve been tough on flu vaccines. Their contents are potentially harmful and their effectiveness from year to year is questionable. Why put your health at risk with a prevention that’s iffy at best?
But H5N1 is completely unlike anything that most of us have ever experienced.
In a recent issue of his Baseline of Health e-letter, HSI Panelist Jon Barron explained why a healthy immune system will probably not offer adequate protection against H5N1. As with the Spanish Flu, H5N1 appears to cause acute respiratory distress syndrome (ARDS). When the immune system recognizes a virus unlike any that’s been previously detected, it launches into overdrive, producing a surge of immune system chemicals that can damage lung tissue when the surge becomes extreme. The most severe cases of ARDS lead to suffocation.
Making an exception
In his Baseline article Jon writes, “Although I am not a fan of flu vaccines in general, if they do announce that they have a vaccine that specifically protects against the particular strain of avian flu in question (the variant that is being transmitted from person to person), it would be worth getting a vaccination.”
I feel much the same as Jon does. There’s no way I’ll drop by my doctor’s office to get a flu shot for the 2005 flu season. But if we hear that H5N1 has mutated into a flu that transmits from human-to-human, and if a vaccine has been properly tested and shown to be reasonably effective (again – BIG “ifs”), then I’ll put aside my usual reservations and get in line for that shot.
If we do get to that point, I hope we’ll all be looking at a glass that’s at least half full.
Sources:
“Signs Point to Global Influenza Outbreak – WHO Warning” Stephanie Nebehay, Reuters Health, 7/22/05, reutershealth.com
“Avian Flu Vaccine Called Effective in Human Testing” Lawrence K Altman, The New York Times, 8/7/05, nytimes.com
“Echinacea and Bird Flu” Jon Barron, Baseline of Health, 8/1/05, jonbarron.org
