Agree on all counts. My point with regard to birds is just that when they "look" sick they are actually far sicker than they appear. A bird may look healthy to the untrained eye but actually show subtle signs of illness. By the time they have nasal symptoms they are usually ready to keel over.
Found this today in LA Times, from Newsday regarding avian vaccine.
Flu vaccine promising
Second round of testing, this time on the elderly, may lead to the prevention of deadly avian outbreak
BY DELTHIA RICKS
STAFF WRITER
October 12, 2005
In a clinical study of a crucial age group, volunteers 65 and older are lining up this week for an experimental vaccine designed to prevent infection with avian influenza, researchers said yesterday.
Experts at the University of Rochester are conducting an arm of the study, aimed at testing how well the shot prompts antibodies against the virus. The vaccine is based on a bird flu strain isolated from a Vietnamese patient diagnosed with avian influenza last year.
With its epicenter in Southeast Asia, where 117 people have contracted the flu since late 2003, global health officials have voiced concern because 63 of them have died. Such a high mortality rate suggests people have few defenses against a strain, which mostly has been passed from birds to humans. If the virus acquires the genetic capacity to spread easily from person to person, the makings of a worldwide pandemic may be at hand. Last week, birds in Romania and Turkey showed signs of the virus.
Dr. John Treanor, lead investigator of the vaccine study in New York, said conducting tests in older people is critical. Older people are more vulnerable to any infection, including seasonal influenza, which claims the lives of 36,000 people annually in the United States, most of them elderly. With an infection that could prove swifter and deadlier, it is important to know how well older people will respond to the vaccine and which dose is most appropriate. About 250 older people will be injected with the experimental vaccine.
Scientists were pleased with results of the first round of study earlier this year, Treanor said, which focused on people from age 18 to 64. The National Institutes of Allergy and Infectious Diseases, the branch of the federal government overseeing the clinical trials, has plans to test the vaccine in children, but a date has not been announced.
"I don't want to sound overly optimistic," Treanor said, "but the basic pathway of how to make a [bird flu] vaccine has been worked out. We know how to make the vaccine.
"But there are still details that are unresolved. And one is how to extend the [vaccine] supply - how can we make enough of it or use a lower dose," so there will be a sufficient supply if mass vaccinations are required.
In clinical trials of people ages 18 to 64, researchers found that the vaccine against the H5N1 bird flu strain worked well, but the best responses were among volunteers who got the highest dose.
"There are some strategies to try - using adjuvants such as aluminum hydroxide," Treanor said. Such an addition could help stretch the vaccine supply. "This is something that is included in tetanus and pertussis. And it does improve the ability of the vaccine to stimulate antibodies. Then we could use a lower dose. But we still have to test that."
Flu vaccine production currently requires the use of millions of chicken eggs. Federal health officials have commissioned studies in which high-tech production methods, using no eggs, are being tested.
Dr. Marc Siegel, an associate professor of internal medicine at NYU Medical Center in Manhattan, wonders whether the emphasis on having people line up for shots is a bit premature.
"If bird flu does mutate, we have no idea whether it will mutate into a form in which the current vaccine is even useful," said Siegel, author of the recently published book "False Alarm: The Truth About the Epidemic of Fear."
"My patients are coming in here panicked," he said. "They want to know what they can do. And right now, I have to tell them, 'Not much.'
"It's not as if this virus doesn't have tendencies that are deadly, but right now, it is mostly killing birds, and before it can routinely kill people, it has to mutate."
Dr. Len Horovitz, a pulmonary specialist at Lenox Hill Hospital in Manhattan, believes that clinically testing a vaccine is important, but he emphasizes that the virus might not mutate.
"There certainly is a lot of hysteria, and right now, I think we need to put things into perspective."
Copyright 2005 Newsday Inc. |
