Skip to content

Cold, Flu, & Cough Health Center

Swine Flu Less Severe for Over-50s?

Pre-1957 Flu Exposure May Protect Against H1N1 Swine Flu
Font Size
A
A
A
By
WebMD Health News
Reviewed by Louise Chang, MD

May 20, 2009 -- People born before 1957 may be less susceptible than younger people to the H1N1 swine flu.

CDC researchers have detected antibodies in the blood of older people that neutralize the new flu bug now sweeping the nation, Daniel Jernigan, MD, MPH, deputy director of the CDC's flu division, said today in a news conference.

Swine Flu Outbreak: Get the Facts

Swine Flu Slideshow

Learn more about the H1N1 swine flu and see what you can do to stay healthy.

View the slideshow.

"We infer from that, there is some level of protection," Jernigan said. "But to prove protection, we look at the effect [the virus has] on the population, and at this point we don't have that information."

Why is 1957 a key year? Every flu season after it first appeared, the deadly 1918 pandemic H1N1 flu bug circled the globe. Each year, the virus acquired changes that made it different from the original virus. But in 1957 there was a new pandemic, this time with an H2N2 virus. The new virus took the place of the old H1N1 bug.

"And so when we talk about the pre-1957 exposures, we are referring to those exposed to the past H1N1 virus that went away in 1957," Jernigan said. "The farther back you go in time, the more likely you are to have been exposed to an H1N1 virus before 1957 -- and exposure to that virus many years ago may allow you to have some reaction to the new H1N1."

The new H1N1 swine flu bug is much different from the 1918 H1N1 virus. It's also much different from the H1N1 seasonal flu virus that still circulates. But something about that pre-1957 bug seems to have left older people with antibodies that neutralize the new flu -- and might offer some protection against it.

Swine Flu Hits Youths Hardest

Whether or not ancient antibodies are protective, many older people are getting sick from the new flu. Some of these illnesses are severe: 13% of people hospitalized with swine flu are 50 or older. And the number of H1N1 cases among older people is increasing.

But H1N1 swine flu is hitting young people hardest. More than 60% of cases are in 5- to 24-year-olds.

Remarkably -- since this is usually the healthiest age group -- 37% of people hospitalized with swine flu are 19 to 49 years old. The median age of a person hospitalized with the new flu is 19.

Today on WebMD

hot toddy
15 tips to help you feel better.
man sneezing into elbow
Do echinacea and vitamin C really help a cold?
 
teen girl coughing
Get a good night’s rest with these remedies.
elder berry
Eat these to fight colds, flu, and more.
 
Natural Cold Flu Remedies Slideshow
Slideshow
cold weather
VIDEO
 
Allergy And Sinus Symptom Evaluator
Article
Boy holding ear
Slideshow
 

Loaded with tips to help you avoid food allergy triggers.

Loading ...

Sending your email...

This feature is temporarily unavailable. Please try again later.

Thanks!

Now check your email account on your mobile phone to download your new app.

woman receiving vaccine shot
Article
woman with fever
Article
 
Waking up from sleep
Article
woman with sore throat
Slideshow