WHO report calls H5N1 vaccine stockpiling premature

first_imgNov 2, 2006 (CIDRAP News) – A group of influenza experts convened by the World Health Organization cautioned today that governments shouldn’t stockpile “pre-pandemic” H5N1 influenza vaccines now, because too little is known about the requirements for an effective vaccine.The group of 22 scientists, who met for 2 days in September, “agreed that governments should not rush to place orders for pre-pandemic vaccines when so many fundamental scientific questions are still outstanding,” says their report.The United States and some other countries have been stockpiling H5N1 vaccines, despite lack of assurance that they would be effective against a pandemic strain. Switzerland recently announced plans to buy enough vaccine for the entire Swiss population.The 16-page report, titled “Influenza Research at the Human and Animal Interface,” emphasizes the continuing seriousness of the threat posed by the H5N1 virus. The meetings on which it was based involved many of the world’s leading experts on influenza.The experts agreed that “the seriousness of the present situation, including the risk that a pandemic virus might emerge, is not likely to diminish in the near future,” the document states.The report also warns that if the H5N1 virus becomes a pandemic strain, it could remain as lethal for humans as it is now, depending on how it acquires the ability to spread from person to person. The current case-fatality rate, with 256 cases and 152 deaths, is about 59%.If the virus becomes more transmissible by acquiring genes from a human-adapted flu virus, its deadliness “would most likely be reduced.” But if it remains “a wholly avian virus” that adapts to humans through a series of mutations, it could remain as deadly as it is now, the experts say.The report says that vaccine development results so far “have not been promising,” in part because H5N1 viruses have branched off into a number of diverse subgroups, and vaccines that seem to work against one clade, or group, don’t work well against others.Many fundamental questions about vaccine development remain to be answered, the group concluded. For example, scientists need to determine which adjuvant (general immune system stimulant) works best and to define what kind of observed immune response indicates an adequate level of protection against the actual virus.The experts say the idea of intradermal injection (injecting vaccine just under the skin instead of into muscle) as a way to stretch vaccine supplies “does not look promising and is not likely to be suitable for worldwide use.”The document cites an urgent need for international standards for evaluating the efficacy of pandemic vaccines. “On such an important matter, it is unwise to leave assessments of appropriate vaccines to competing manufacturers,” it states.The report describes human H5N1 disease as “fundamentally different” from ordinary flu, marked as it typically is by progressive viral pneumonia, acute respiratory distress, and sometimes diarrhea and liver dysfunction. The disease’s severity may be a result of the “cytokine storm,” or flood of chemical messengers causing intense inflammation in the lungs, but it is not clear whether the cytokine storm is the cause or the result of extensive tissue damage and disease.Some other observations and recommendations in the wide-ranging report are as follows:A simple, rapid, and reliable diagnostic test for use in the field and at the patient’s bedside is urgently needed.Research is needed to determine what makes children and young adults especially vulnerable to infection.Recent serologic studies have shown very little evidence of asymptomatic or mild H5N1 infections in humans. All healthcare workers studied in Thailand tested negative, and samples submitted from Djibouti, Nigeria, Kazakhstan, and Mongolia for testing at the US Centers for Disease Control and Prevention were all negative. However, some family members of patients in Vietnam tested positive.Studies are needed to determine if a genetic predisposition increases the risk of human infection or of human-to-human transmission among blood relatives.Resistance to the first-choice antiviral drug, oseltamivir, has been seen in a few patients, but studies show a low rate of oseltamivir-resistance mutations in H5N1 viruses in birds. Resistance to amantadine, the second-choice antiviral, varies among H5N1 strains.Mallard ducks are now seen as the leading vectors in the geographic spread of H5N1; mute swans are highly susceptible to the disease but probably don’t spread it.Regarding poultry outbreaks in China, “the situation is severe and not yet fully under control,” and vaccination of the entire poultry population is needed.To control H5N1 disease in poultry, vaccination, coupled with appropriate monitoring, should be used when culling is impracticable.Scientists who track the disease in ducks should adjust their sampling procedures to reflect that ducks now shed more virus in their respiratory secretions than in feces.The experts’ warning against stockpiling of H5N1 vaccines was hailed by infectious disease expert Michael T. Osterholm, PhD, MPH, as appropriate advice in view of the virus’s genetic variability.”I think this report will result in a pause in what I think has been a recent epidemic of vaccine results by press release,” said Osterholm, director of the University of Minnesota Center for Infectious Disease Research and Policy, publisher of the CIDRAP Web site.He also said the report makes clear that the risk of a severe pandemic like that of 1918 still exists. “Some have suggested that talking about any kind of pandemic other than [the moderate pandemic of] 1957 or 1968 was tantamount to scaremongering,” but the report makes clear that from a virologic standpoint, the H5N1 virus could remain highly deadly while evolving into a pandemic strain, he said.”This is a really thoughtful report, and it adds a tremendous amount to the ongoing discussion,” Osterholm said.See also:Nov 2 WHO report “Influenza Research at the Human and Animal Interface”last_img read more

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2007 SUMMIT COVERAGE: Businesses must overcome ‘fog’ of pandemic preparedness

first_img See also: Adding to that miasma is the state of US healthcare. In part because of a shortage of workers and the physical limitations of medical centers, the system has little “surge capacity” for the huge influx of patients a pandemic would cause. “We have basically taken [the healthcare] system and sucked it to the bone,” Osterholm said. Maintain flexibility. Osterholm recognized the uncertainty involved in pandemic planning and stressed that plans need malleability so they can adapt to the elusive realities of a pandemic. “Anyone who develops a concrete plan is making a mistake,” he said. “Be capable and be flexible. Another layer of mist comes in the form of making decisions about vaccines and antiviral drugs. Osterholm lauded companies like Roche for increasing production of antiviral drugs like osteltamivir (Tamiflu), but said it remains unclear how effective these drugs will be against H5N1 if it becomes the pandemic strain. How high mortality rates will be Overcome pandemic fatigue. Recognize that some executives may see pandemic planning as no longer important, Osterholm said, calling the phenomenon “pandemic fatigue” and saying, “Acknowledge, accept, and plan around pandemic fatigue.” Osterholm spoke at CIDRAP’s “Business Preparedness for Pandemic Influenza: Second National Summit,” held this week for hundreds of leaders in business, government, and academia. How effective and plentiful antiviral drugs and vaccines will be—and when they’ll be ready Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy (CIDRAP), publisher of CIDRAP News, said that several factors cloud the preparedness landscape: Even if companies stockpile antivirals, they face another dilemma: when to use them. If they were to withhold them during a first pandemic wave anticipating a more severe second wave that didn’t happen, people would question the decision, Osterholm said. Likewise, leaders could decide to distribute stockpiled drugs during the first wave, only to discover that the second is more severe. “When do you blow your wad?” he asked. How our communities will mitigate damage “Pre-pandemic” vaccines can be stockpiled in the hope that they may provide some protection against the influenza strain that ultimately causes a pandemic. However, as pointed out by vaccine expert Gregory Poland, MD, in a separate summit presentation Tuesday, a vaccine targeted to the specific pandemic strain would take months to develop and distribute. Feb 7, 2007 (CIDRAP News) – Orlando, FL – As businesses develop pandemic preparedness plans, they need to cut through a “fog” of uncertainty about exactly what pandemic influenza will look like and how their companies will be able to respond to it, infectious disease expert Michael Osterholm, PhD, MPH, said at a summit in Orlando Monday. The result, said Osterholm, is that “the availability of protective vaccine during the first wave of a pandemic just won’t be there.” He added, “For most of the world’s population, a vaccine will never be available throughout the duration of a pandemic.” Work around “just in time.” “Don’t try to change the global just-in-time economy,” he said. “That’s like swimming up Niagara Falls. Forget it. You’ve got to work around it.” And with estimates of the mortality rate in a pandemic ranging widely, Osterholm surmised, “We don’t really have a clue” about how many people will succumb. How many waves of the pandemic will occur, and how severe they’ll be Pandemic planning can produce its own haze as planners grapple with issues like ensuring their supply chain or determining government’s role. “We talk about what we might do or can do, but we really don’t know,” Osterholm said. “There are so many uncertainties.” This extends to experts’ estimates of how a pandemic might behave. “We have only a general sense of what the next pandemic influenza strain is capable of doing in terms of human illness or subsequent collateral damage,” he said. Add to that today’s just-in-time economy, in which supplies arrive as they are needed so that companies minimize storage costs. “It is the reality of today’s economy,” Osterholm said. “It’s what MBAs are made of.” That reality, though, means that “even a hiccup” of disruption will mean serious shortages, he predicted. Full text of Feb 2007 HHS report on community mitigation measureshttp://www.pandemicflu.gov/professional/community/community_mitigation.pdf Other steps businesses can take, according to Osterholm, include: “You’re not stuck to a plan,” he said. “You’re stuck to a process.” In addition, said Poland, director of the Mayo Vaccine Research Group in Rochester, Minn., drug companies—even at maximum worldwide production—could deliver only enough vaccine to inoculate 1% to 2% of the world’s population. Shining some light into the pandemic cloud, however, is the recent document on community mitigation measures by the US Department of Health and Human Services (see links below). “You don’t want to have a [pandemic planning] policy inconsistent with this document,” Osterholm said. How our overloaded healthcare systems will cope How our global just-in-time economy will affect access to goods and services He took his “fog of pandemic preparedness” concept from the theory of the “fog of war,” a state of ambiguity soldiers can find themselves in when they doubt their own capabilities and feel unsure of their adversary’s capabilities and intentions. Feb 1 CIDRAP News story: “HHS ties pandemic mitigation advice to severity” Learn from veterans. We need to look at those in the military who have studied the fog of war to explore what to do when unsure about what steps to take.last_img read more

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