pertussis booster for many adolescents and adults
Canada's National Advisory Committee on Immunization now recommends a pertussis booster for many adolescents and adults.
Prior to 1997 everybody got the whole cell pertussis vaccine. Now researchers are worried that the vaccine wasn't very effective.
In fact, cases of whooping cough have risen dramatically since 1990...possibly because the whole cell vaccine was only 20% to 60% effective...and its efficacy decreases with time.