(WEST LAFAYETTE, IN) - As confirmed cases of H1N1 flu increase in Indiana, Purdue University's Dr. David Sanders explains what researchers are learning about the virus.
He says unlike seasonal flu where older adults are susceptible, H1N1 is primarily affecting older children and younger adults.
Dr. Sanders says three hypothesis, all of which may be true, have emerged to explain why that age group is most susceptible to it.
One theory says H1N1 is closely related to a flu virus that circulated among the human population until 1957.
There's some evidence that people born before 1957 who were exposed to that flu have a certain amount of residual immunity to it.
Another theory is the combination of flu vaccines elderly people have received over the years are providing some protection for that age group.
And the third hypothesis is the virus produces an inappropriate immune response in people who have a robust immune system such as older children and young adults.
The collateral damage to the cells make the body more susceptible to other infections not related to the H1N1virus itself.
Regardless, Dr. Sanders recommends getting the H1N1 vaccine when it's available to help stop the spread of the virus to others.
He urges people with flu like symptoms to stay home.
He also recommends infected people avoid going to a hospital emergency room and see their doctor or nurse practitioner instead.
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