Scientists Race to Design Universal Flu Vaccine
Feb. 19--A global corps of flu scientists are already planning next year's vaccine while a cadre of investigators is taking an even bolder step -- racing to design the first universal influenza vaccine, a one-time immunization that could end the autumn ritual of getting a flu shot.
Flu experts say the key to better controlling the spread of the flu is producing a new generation of vaccines. And the first step in that direction, they say, will be next year's flu vaccine, which is expected to have four components rather than the usual three to fight circulating strains.
Next season's vaccine will have two inactivated A viral strains and two inactivated B strains. The current vaccine has two As and one B.
"The current vaccine is far from perfect but it is the best tool we have," Dr. Thomas Frieden, director of the Centers for Disease Control and Prevention, said during a recent news briefing. "The goal is to develop a vaccine that you don't have to give every year."
"We are working with the National Institutes of Health to come up with a better vaccine," Frieden added, noting, "We would like a vaccine that is universal." Those plans are part of a worldwide race to produce a universal vaccine that is given as a one-time shot with only periodic boosters.
Academic centers and biotech companies in this country and abroad are working on universal flu-vaccine candidates. None is as yet near fruition -- and for good reason. This type of immunization is a tall order for science.
A universal vaccine, flu scientists say, would have to be effective against all strains of seasonal flu and would also have to provide protection against a pandemic strain, should such a virus arise.
'An enormous improvement'"The development of a uniformly stable flu vaccine that didn't have to be changed every year would be an enormous improvement over what we have now," said Dr. Bruce Farber, chief of infectious diseases at North Shore University Hospital in Manhasset.
The current vaccine requires reformulation each year, Farber said, because flu viruses are constantly tweaking the proteins on their outer coat. Think of a flu virus as a submicroscopic mace -- the spiked end of the medieval weapon. The spikes on the flu virus are the proteins hemagglutinin and neuraminidase, which are in constant flux.
Their slight changes keep flu viruses a step ahead of the human immune system because the transformed proteins mean there will always be susceptible human hosts -- and therefore survival of the virus.
Yet those infinitesimal changes on the outer coat of flu viruses have also meant the need for an enormous public health enterprise to produce an annual, reformulated vaccine to guard against current circulating strains.
No other vaccine is produced in such vast quantities -- 400 million doses worldwide every year. So far this flu season, about 40 million of those doses have been administered in the United States, according to the CDC.
But Frieden and other experts say they would prefer to abandon the current reliance on the millions of fertilized hens' eggs required to manufacture each year's vaccine. It is a slow, World War II-era technology, they say, which adds months to the production process.
A few smaller U.S. manufacturers have begun using techniques similar to those used to produce other types of vaccines.
Universal flu vaccines could be made quicker with modernized techniques, experts say, in the event of a global flu emergency.
Advances in vaccine technology come as Long Islanders continue to tough it out through the current flu season, one of the worst in a decade.
The New York State Department of Health still considers flu transmission activity particularly high on Long Island. The biweekly map of New York's counties produced by health department epidemiologists has shown Nassau and Suffolk red all year, the color for the highest level of transmission.
Some counties see declineSeveral upstate counties have begun to see a decline in flu activity, but the season runs through March, experts say.
Six children have died of the flu so far this season statewide, Health Department data show. And nearly 35,000 cases of influenza have been confirmed by the infectious diseases division of Wadsworth Laboratory, a state Health Department facility.
The number of confirmed flu cases represents only a fraction of people stricken this season. Most people self-treat the flu.
A universal flu vaccine would not eradicate the flu the way concerted vaccination efforts have knocked out smallpox and are poised to do with polio, scientists say, but a universal vaccine could help limit much of the annual toll of human suffering and death.
The World Health Organization estimates that cases of severe influenza cause about 250,000 to 500,000 deaths globally each year. Epidemics, WHO officials say, cost the United States alone anywhere from $71 billion to $167 billion.
"There has been a lot of interest in a universal vaccine and that has been true for a long time," said Dr. Doris Bucher, who heads microbiology and immunology at New York Medical College in Valhalla, Westchester County. Her laboratory provides all the seed strains of inactivated viruses that are used by vaccine manufacturers in this country and elsewhere in the world.
Interest in a universal vaccine dates to the late 1980s, Bucher said, when researchers first suggested that specific molecular sites in the flu virus that never change might serve as universal-vaccine targets.
But in more recent years, she added, they have begun to focus on parts of hemagglutinin -- which has a potent degree of stability deeper within the virus, suggesting it is not as variable as once thought.
Bucher predicts a candidate vaccine won't be available anytime soon. "This isn't an easy task," she said.
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