Well, DG, the problem is we don't know enough about the virus to make a vaccine yet. In fact, the test for the current group of avian flu cases depends on identification from the virus circulating in fall, of 2004.
It's thought that the virus has changed enough that there are false negatives, leading to a whole host of difficulties. In fact, it's fairly certain that there are an unknown number of false negatives, and that we cannot currently identify avian flu from the tests we presently have.
I'll post a commentary from Recombinomics here in a second.
Pandemic Flu False Negatives in Vietnam and Korea
Recombinomics Commentary
May 8, 2005
>>Genetic sequences from more recent versions of H5N1 are needed to produce more up-to-date test components, called primers.
Primers are tiny strands of synthetic nucleic acid used in PCR or polymerase chain reaction testing. If they are a perfect match for the influenza strain, primers used in flu tests should bind to the RNA of the virus.
Kobasa and lab technician Laura Hart spent several weeks at the National Institute for Hygiene and Epidemiology in Hanoi, sharing diagnostic expertise and helping Vietnamese scientists assess their testing proficiency.
That is when the problem with the primers came to light.
"There've been enough changes in the viruses between last year and this year that we found some of our PCR primers did not work that well," says Kobasa, a researcher in the division of respiratory viruses.
<<
The comments above offer some explanation for the false negatives in southern Vietnam. Earlier this year, tests from the National Institute for Infectious Diseases (NIID) in Tokyo found that several samples that tested negative at the Pasteur Institute in Ho Chi Minh City tested positive in Tokyo. The number of false negatives was initially reported as 7 of 30. The number was raised to 11 of 30 in follow-up NY Times report.
These numbers indicated that approximately 80% of the H5N1 positive cases in southern Vietnam were being missed. Recent reports indicated a missing amino acid has been detected in isolates in northern Vietnam, suggesting those isolates were recombinants between isolates from Vietnam and isolates from China. It seems likely that there have been primer problems in northern Vietnam also, which may explain why northern Vietnam sent 1000 samples to CDC for testing.
The lowered sensitivity for tests in the south may be do in part to an evolving H5N1, which continues to recombine with the many versions of the virus in Vietnam and new versions brought into the area by migratory birds. This primer related sensitivity problem may also explain why Thailand failed to identify any human cases this season when H5N1 was detected throughout the country in a wide variety of domestic and wild birds. Human Influenza A cases were testing negative for H5N1. The testing was almost certainly also based on the 2004 sequences, which had changed in 2005.
For Vietnam and Thailand, new probes relied in part on new sequences. However, primer issues may have also played a role in the WHO's failure to find WSN/33 sequences in swine in Korea. However, for the Korean sequences, the 2004 sequences were known in 2004 and had been deposited at GenBank in 2004. However animal quarantine in Korea as well as consultants to the WHO failed to confirm the data. In 2005 they did find H1N2 sequences in Korean swine, but these sequences had been reported previously in swine from the United States and Korea. They were quite different from the human WSN/33 sequences, or the original WSN/33 sequences or the closely related sequences found in swine.
The WHO had written up a release that described these 27 isolates from 2 farms in Korea. Although a draft was distributed to media, it remains unclear if the release ever went out to a larger audience. A small number of these isolates were sequenced and no WSN/33 was found in the limited number of sequences generated. However, it remains unclear if the primers used to generate the H1N2 sequences would have detected WSN/33 sequences.
Thus, the lack of primer specificity may have generated false negatives in Vietnam and Korea. The inability of the WHO to monitor H5N1 and WSN/33 seriously impacts any intervention strategy. The results from the 1000 samples from northern Vietnam have not been released. It remains unclear as to how much sample collection has been done from patients with flu-like symptoms. In northern Vietnam the case fatality rate has fallen to 20%. Many of the recovered patients are H5N1 positive, but have a relatively short hospital stay, which suggests a large number of milder cases may not be seen by physicians or hospitals.
Similarly, it is not clear where the WSN/33 sequences are in Korea, or how the 1933 human lab virus made its way into swine in Korea. Since Korea imports pigs from the United States and H1N2 was detected in the United States prior to being detected in Korea, the H1N2 and WSN/33 infections could date back to 2001 or earlier.
Strategies based on control of H5N1 bird flu or WSN/33 pandemic flu dependent on early detection have limited chance of success if the presence of the virus is largely unknown.
http://www.recombinomics.com/News/05080501/False_Negatives_Vietnam_Korea.html
Then we're screwed. I'm not willing to accept that yet without an admission from the pharmaceutical companies.
If it takes six months to manufacture and distribute a vaccine, and if they don't have one already in the works for avian flu, the earliest we could see one is in November if they start tomorrow, and that's too late.
The only hope we'd have then is that it somehow doesn't spread very fast in Asia and doesn't hop continents.
Judith Anne I posted this story separately but since I dont know how to 'link' to other articles here I'm going to repost the news story here since it may be relevant to your point...hope that is ok.
Experts mull possibility of vaccine protection against pandemic flu strains
CP ^ | 24/04/2005 3:48:00 PM | Canadian Press
Posted on 04/27/2005 11:53:34 AM EDT by FYREDEUS
TORONTO (CP) - When the next influenza pandemic hits, vaccine will be the key defence for countries that can afford it. But there will be inevitable if agonizing months between the emergence of a pandemic strain and the point when vaccine is ready to be plunged into arms.
Some influenza experts, though, have started to debate whether it's really necessary to wait for a pandemic to ignite before moving to protect people against virus subtypes on flu watchers' Most Feared list.
Wracked by concerns the world might be watching the unfolding of a pandemic, they are searching for out-of-the-box solutions to reduce the devastation to human health and the global economy that one would wreak.
Dr. Jesse Goodman is among those mulling over the notion of trying to create some population immunity to threatening flu strains during interpandemic times.
The idea is still "very exploratory," admits Goodman, director of the Food and Drug Administration's centre for biologics evaluation and research, which regulates vaccine production and sales in the United States.
"I think there is an opportunity to think about: Can we prepare and provide some protection not in a crisis mode, but more ahead of time? Ahead-of-the-curve kind of mode," he suggested in a recent interview from Washington.
"I think this is a strategy worth considerable thought and discussion. . . . (But) it's not something one would just do without a lot of thought and evaluation."
The idea would most likely entail adding a fourth component to the annual flu shot, which currently protects against the three flu strains - two influenza A and one influenza B - experts predict will be dominant in the coming flu season.
Adding a fourth strain could awaken or prime the immune system to viruses it's never seen before. Like the H5N1 strain smouldering in Southeast Asia. Or the H7N3 strain behind British Columbia's 2004 avian flu outbreak. Or H2N2, the 1957 pandemic strain recently sent in unlabelled vials to more than 5,000 labs around the world.
(While the flu world fears H5N1's lethality, some experts argue H2N2 is the top contender for the next pandemic strain because of its proven ability to infect and spread among humans.)
It is widely believed people would need at least two shots - a primer and one or two boosters - to get good protection against a flu strain their immune systems has never battled.
This idea would see a generic primer to H5N1 or H2N2 delivered well in advance of need. Once a pandemic starts and a vaccine targeting the specific strain is produced, the booster or boosters would be administered. If a large segment of the population was pre-primed, vaccine production time could be cut dramatically.
University of Ottawa flu expert Dr. Earl Brown says the approach could give pre-vaccinated people "a leg up."
"It has some merit in that you should have some (protective) advantage," Brown says, adding that even without the booster shot, people who'd been primed might have some protection. "Maybe some people wouldn't get as severely diseased."
The head of the World Health Organization's global influenza program also sees the theoretical appeal of the notion.
"Logistically, it could make sense that during ... peace times like now you vaccine everybody and then when it comes to mass vaccination needs . . . you'd only need to apply one dose," says Dr. Klaus Stohr.
But Stohr is also quick to point out what might be the single biggest impediment to the idea - the issue of liability. While flu shots are considered to be among the safest medical interventions available to public health, no vaccine or drug is risk-free.
The flu community knows that too well, having learned the lesson the hard way during from the swine flu debacle. In the spring of 1976, four U.S. Army recruits fell ill with what was discovered to be a swine flu similar to the 1918 strain that caused the worst infectious disease outbreak in recorded history, the pandemic know as the Spanish Flu.
Fearing the 1918 virus was readying itself for a new assault, the U.S. government mounted a mass vaccination campaign aimed at protecting every American.
Swine flu never took off, but another health threat did - Guillain-Barre syndrome.
A small but significant number of people who got the swine flu shot developed the potentially fatal neurological condition, resulting in major lawsuits. To this day, the rare syndrome remains linked to influenza vaccination, though only one study has shown an association and then only at the rate of one case per million people vaccinated.
Still, swine flu instantly comes to mind when the flu community starts discussing the ethics and liability concerns raised by the notion of vaccinating people against a theoretical risk.
"The bar does rise," Brown admits.
"If you vaccinate your whole country, you've got to be concerned that everybody for the next two or three months is going to blame whatever bad happens on the vaccine."
Vaccine expert Dr. John Treanor sees other problems as well. Treanor thinks pre-priming might actually work, though it would need to be proved through testing.
But he says with current flu vaccine production limitations - old technology, capacity to make vaccine for only a fraction of the world's populace - "it's probably not going to fly.
"It's been quite difficult just to make the regular vaccine. Add another component, it just makes it that much harder. It might make it so hard it couldn't be done," says Treanor, director of the vaccine treatment and evaluation unit at the University of Rochester, one of three centres testing an experimental H5N1 vaccine for the U.S. government.
Stohr points out another issue. Pre-priming, if it worked, is only really an option for affluent countries.
"We must also not forget that we are talking about a privileged part of the population. Those who can already afford the seasonal vaccine would have access to it. And the others would again draw the short straw."
Goodman knows all these arguments, but feels the notion is still worth exploring.
"It needs a careful discussion" he says.
"But in the long run, if you really do think about it more optimistically, what you realize is that with good surveillance systems we do have the possibility of knowing what are potential pandemic threats and thinking about these kinds of strategies."