SCIENCE / MEDICINE : Tests on Whooping Cough Vaccine

Italian researchers are testing a new vaccine against pertussis (whooping cough) that they hope will be safer and more effective than existing vaccines. Current vaccines use inactivated cells of Bordetella pertussis, the microorganism that causes the disease, but these preparations have been found to produce convulsions or seizures in one of every 750 vaccinated children and brain damage in one of 300,000.

The pertussis bacterium produces a toxin that can cause death. Molecular biologist Luciano Nencioni and his colleagues at the Sclavo Research Center in Siena have genetically engineered the bacterium so that it produces a harmless version of the toxin. When used as a vaccine, the harmless toxin stimulates immunity against the virulent form. Nencioni said the harmless toxin produces a much stronger immune response than a chemically detoxified form that other researchers are now testing.

The vaccine is now being tested in 100 children.