Would Swine Flu In 1976 Protect You Against Today's H1N1?

By Richard Knox

We have received so many intriguing listener and reader questions about the swine flu over the last few weeks that we're going to do our best to tackle one a day until the pandemic subsides or we've exhausted your curiosity.

(2009 H1N1 virus/C. S. Goldsmith and A. Balish, CDC)

To kick things off, we have a question from Nancy DeWeese, who asks:

I and my daughters (then 4 and 8) were laid low -- really low -- for several days in 1976 with the flu. We hear now it was probably the 'swine flu' of the day. Any connection between that virus and today's H1N1? Any protection for us as a result?

The short answer, Ms. DeWeese, is that you and your daughters did not have swine flu back in 1976.

Here's more from Dr. William Schaffner, chairman of preventive medicine at Vanderbilt University: "You can say that with great assurance. There were no reported cases of swine flu outside of Fort Dix, NJ."

That's where the virus first appeared, infecting about 230 Army recruits and killing one. The Fort Dix outbreak touched off fears of a potential pandemic and led President Ford to order mass vaccination against the newly discovered virus. About 45 million Americans were vaccinated before the campaign was halted by reports of a possible neurologic side effect called Guillain-Barre syndrome.

Undoubtedly, you and your girls got one of the seasonal flu viruses circulating in 1976, possibly the H3N2 strain.

You didn't ask, but you might wonder: If you were among those who got vaccinated against the 1976 swine flu virus, might you have some protection against the 2009 version? Unfortunately, no.

There are hundreds if not thousands of swine flu viruses. Many of them are designated H1N1, as the 2009 swine flu virus is. But Dr. Schaffner says the 1976 swine flu virus is genetically quite different from today's. So the 1976 vaccine is not believed to offer any protection against the current pandemic.

There's one glimmer of hope. Last week at meetings of the Infectious Diseases Society of America, some researchers said people who have had infections of H1N1 viruses in the past may have some degree of protection. But there's no way to know what kind of flu virus you and your daughters had 33 years ago.

If you've got a swine flu question, email us at shots@npr.org.