Science / Medicine : New Vaccine Against Whooping Cough Tested
A promising candidate for a new, safer vaccine against whooping cough has been developed by a team of Italian, American and Japanese researchers, the scientists said Thursday.
“All the animal studies have confirmed that the molecules we have identified are excellent vaccine candidates,” said researcher Rino Rappuoli of the Sclavo Research Center in Siena, Italy.
Tests of the vaccine on human volunteers began recently and early results should be known in “a couple of months,” Rappuoli said in a telephone interview.
Whooping cough kills an estimated 1 million children annually around the world.
Although a vaccine is widely available, many parents elect not to give it to their children because it can cause serious side effects, including brain damage and other nervous system complications.
The three-component DPT vaccine guards against diphtheria and tetanus as well as whooping cough, whose scientific name is pertussis because it is caused by a type of bacteria known as Bordetella pertussis.
Writing in last Friday’s Science magazine, scientists from the Medical College of Wisconsin in Milwaukee and the National Institute of Health in Tokyo as well as the Sclavo center said they used genetic engineering techniques to produce a nontoxic version of the toxin, or chemical poison, produced by the B . pertussis bacteria.
The unaltered toxin forms the basis of the current vaccine; it is first weakened by a chemical process, then injected, tricking the body into producing antibodies against the pertussis bacteria.
Although the genetic engineering procedure produces nontoxic mutant toxin molecules, the researchers said animal studies indicate that these molecules retain their ability to trigger the immune response required to prevent whooping cough but without the harmful side effects of the current vaccine.
In tests in mice, the experimental vaccine was able to protect the animal against a lethal dose of virulent whooping cough bacteria, they said. “So far, so good. Everything we anticipated is happening,” Rappuoli said.
