Science takes best shot at ‘flu

The Associated Press
Lauran Neergaard

WASHINGTON–The descriptions are haunting.
Some victims felt fine in the morning and were dead by night.
Faces turned blue as patients coughed up blood. Stacked bodies outnumbered coffins.
A century after one of history’s most catastrophic disease outbreaks, scientists are rethinking how to guard against another super-‘flu like the 1918 influenza that killed tens of millions as it swept the globe.
There’s no way to predict what strain of the shape-shifting ‘flu virus could trigger another pandemic or, given modern medical tools, how bad it might be.
But researchers hope they’re finally closing in on stronger ‘flu shots–ways to boost much-needed protection against ordinary winter influenza and guard against future pandemics at the same time.
“We have to do better and by better, we mean a universal ‘flu vaccine,” said Dr. Anthony Fauci of the U.S. National Institutes of Health.
“A vaccine that is going to protect you against essentially all, or most, strains of ‘flu,” he noted.
Labs around the country are hunting for a super-shot that could eliminate the annual fall vaccination in favour of one every five years or 10 years, or maybe, eventually, a childhood immunization that could last for life.
Fauci is designating a universal ‘flu vaccine a top priority for NIH’s National Institute of Allergy and Infectious Diseases.
Last summer, he brought together more than 150 leading researchers to map a path. A few attempts are entering first-stage human safety testing.
Still, it’s a tall order. Despite 100 years of science, the ‘flu virus too often beats our best defences because it constantly mutates.
Among the new strategies: researchers are dissecting the cloak that disguises influenza as it sneaks past the immune system, and finding some rare targets that stay the same from strain to strain, year to year.
“We’ve made some serious inroads into understanding how we can better protect ourselves,” said well-known ‘flu biologist Ian Wilson of The Scripps Research Institute in La Jolla, Calif.
“Now we have to put that into fruition,” he added.
The sombre centennial highlights the need.
Back then, there was no ‘flu vaccine. It wouldn’t arrive for decades.
Today, vaccination is the best protection and Fauci never skips his. But at best, the seasonal vaccine is 60 percent effective.
Protection dropped to 19 percent a few years ago when the vaccine didn’t match an evolving virus.
If a never-before-seen ‘flu strain erupts, it takes months to brew a new vaccine. Doses arrived too late for the last, fortunately mild, pandemic in 2009.
Lacking a better option, Fauci said the nation is “chasing” animal ‘flu strains that might become the next human threat. Today’s top concern is a lethal bird ‘flu that jumped from poultry to more than 1,500 people in China since 2013.
Last year it mutated, meaning millions of just-in-case vaccine doses in a U.S. stockpile no longer match.
The new vaccine quest starts with two proteins, hemagglutinin and neuraminidase, that coat the surface of the ‘flu virus.
The “H” allows ‘flu to latch onto respiratory cells and infect them. Afterward, the “N” helps the virus spread.
They also form the names of influenza A viruses, the most dangerous flu family.
With 18 hemagglutinin varieties and 11 types of neuraminidase (most carried by birds), there are lots of potential combinations. That virulent 1918 virus was the H1N1 subtype; milder H1N1 strains still circulate.
This winter H3N2, a descendent of the 1968 pandemic, is causing most of the misery.
Think of hemagglutinin as a miniature broccoli stalk. Its flower-like head attracts the immune system, which produces infection-blocking antibodies if the top is similar enough to a previous infection or that year’s vaccination.
But that head also is where mutations pile up.
A turning point toward better vaccines was a 2009 discovery that, sometimes, people make a small number of antibodies that instead target spots on the hemagglutinin stem that don’t mutate.
Even better, “these antibodies were much broader than anything we’ve seen,” capable of blocking multiple subtypes of ‘flu, said Scripps’ Wilson.
Scientists are trying different tricks to spur production of those antibodies.
In a lab at NIH’s Vaccine Research Center, for instance, “we think taking the head off will solve the problem,” Graham said.
His team brews vaccine from the stems and attaches them to ball-shaped nanoparticles easily spotted by the immune system.
Yet lingering mysteries hamper the research.
Scientists now think people respond differently to vaccination based on their ‘flu history.
“Perhaps we recognize best the first ‘flu we ever see,” said NIH immunologist Adrian McDermott.
The idea is that your immune system is imprinted with that first strain and may not respond as well to a vaccine against another.
“The vision of the field is that ultimately if you get the really good universal ‘flu vaccine, it’s going to work best when you give it to a child,” Fauci said.