Inside us, survival of the fittest plays out with a new flu virus on the attack; scientists stand ready to help our trusty antibodies prevail.
By Rick Ruggles
WORLD-HERALD STAFF WRITER
Flu viruses are driven to change by the same process that makes animals adapt: the instinct to survive.
Human beings fight an ongoing battle to produce virus-fighting antibodies, while viruses work to elude those antibodies.
In a way, it's the balance of nature, a "Wild Kingdom"-style skirmish that takes place inside the human body.
"They change, they adapt, they mutate," said Dr. Charles Wood, director of the Nebraska Center for Virology. "It's the survival of the fittest."
The severity of the current H1N1 flu strain challenging the globe isn't yet clear.
Dr. Peter Palese, a flu researcher at New York's Mount Sinai Medical Center, said the new virus appeared to be similar enough to other common flu strains that "we probably all have some type of immunity."
Palese said there "is no real reason to believe this is a more serious strain."
An official with the federal Centers for Disease Control and Prevention said Friday the new flu virus lacks the genetic traits that made the 1918 pandemic strain so deadly.
Experts say viruses are always modifying themselves, but those changes typically are modest and the viruses can be fought off.
If they manage to make a big leap in their makeup, the antibodies produced inside humans won't recognize them and those viruses will have the potential to do great harm.
"You can't mount an immune response to something you haven't seen before, "said Dr. Chris Destache, a Creighton University professor who teaches pharmacy students about infectious diseases.”It's basically Darwinian theory," Destache said. "Viruses want to survive."
It's far from certain that the current flu outbreak will become anywhere near as severe as the 1957 Asian flu, which killed 70,000 Americans and 2 million people worldwide, or other major outbreaks. Even in a typical year, the flu kills about 36,000 Americans.
"This could fizzle," said Dr. Marvin Bittner, a Creighton University and VA Medical Center infectious disease expert.
It eventually will be quashed, regardless of its severity. The virus will dissipate naturally or will be forced into submission by a man-made vaccine.
"That's just the nature of things," said Dr. Steven Hinrichs, chairman of the University of Nebraska Medical Center's department of pathology and microbiology. "It’s happened in the past. It will happen again."
Hinrichs said he and some other scientists do not believe viruses are alive. They can't replicate on their own, he said. They must be part of a living cell to do that.
Bittner, on the other hand, believes they are alive. They have genes and use cells to make proteins, he said, and thus are alive. "We're getting into philosophical territory here," Bittner said.
Regardless, the current virus that is at war with people evidently is a combination of different flu strains originating in people, birds and pigs.
A virus is a tiny organism that looks like a bag of genetic material and is surrounded by a protein shell. It thrives inside cells and can survive briefly on hands and surfaces.
The virus strives to get inside the cells of a person "a host" and multiply while antibodies work to disable it. In the process, the genetic material of different strains of viruses sometimes mix and form a new strain, which then can evade the body's natural defenses.
If the viruses thrive, they spread to other cells and sicken the host. The host may then cough and expel the viruses to other people, sickening them.
And so the virus rolls on.
Bittner said it's possible that this flu so far has held a tighter grip on Mexico because people live in closer quarters there than in the United States. Perhaps, Bittner said, the fact that warmer weather is arriving and people will spend more time outdoors will help prevent an intense spread of this flu.
The CDC said last week that creating a vaccine to fight this flu virus "is something that we are looking at very intently."
The CDC's acting director, Dr. Richard Besser, said the agency is growing "seed stock" of this virus so it can manufacture a vaccine if necessary.
Hinrichs said creating the vaccine typically has involved infecting chicken eggs with the virus, collecting the virus and chemically removing the portion that enables the virus to replicate.
The vaccine consequently contains only a portion of the virus, but the body learns to recognize it and eliminate it.
Scientists annually create a vaccine based on the flu virus strains they expect to circulate widely.
Bittner said they make those predictions early in the year and ship out the vaccine about eight months later.
Creating enough vaccine to help the nation fight the current outbreak also would take months, and hundreds of thousands of eggs, Bittner said.
Sometimes scientists run into technical problems, and there's no guarantee the vaccine would be effective.
"They've got a lot of work to do," he said. "This is not going to happen immediately."