Some parents bypassing chickenpox vaccine.

By Luciana Lopez, The Oregonian, Portland, Ore. Knight Ridder/Tribune Business News

Feb. 7--Elaine Fawcett's two daughters haven't had chickenpox yet, but it's not for lack of trying.

In December, Fawcett exposed them to children with the virus, hoping the girls would get chickenpox now, because the disease can be much more serious in adults. She quarantined the girls after exposure, waiting for them to get the blisters that herald the disease's itchy onset.

Her 1-year-old got a few slight bumps that might have been chickenpox; her 4-year-old, nothing. So Fawcett is trying again.

"I had it; it was no big deal," said Fawcett, who lives in West Slope. "I just really believe in letting the immune system do its thing."

Deliberately exposing children to chickenpox to give them immunity once was fairly common, but these days most kids are given a vaccine approved for use in the United States in 1995. The varicella vaccine is credited with reducing the number and severity of …