A majority of patients were infants and 18 of those died. There is a vaccine for whooping cough but newborns are too young to get it so doctors are trying a new method to protect babies starting at birth.
A government advisory panel is trying to have babies immunized at birth by vaccinating their mothers in the last trimester of pregnancy.
Newborns can't get vaccinated until they're two months old.
It takes five doses of the vaccine, spread out from two-months to kindergarten age, to immunize a child against whooping cough.
"By vaccinating the mother, mother will then pass her immunity to the baby, and when baby is born that baby will have protection," said Dr. Cody Meissner, a professor of pediatrics at Tufts University School of Medicine. Meissner was part of the panel that developed the recommendation.
However, the vaccine is not perfect. Kids who are fully immunized usually start to lose protection after about five years.
Boosters are recommended for adolescents, and suggested for everyone over age 19.
"The organisms that cause these infectious diseases are still around us, and if people do not get vaccinated they run the risk of getting infected," Meissner said.
By adding pregnant women to the list of those who need the vaccine, doctors hope to make a drastic cut in infections among those who need the most protection.
The recommendation calls for women to get the vaccine during the 27 to 36 week of pregnancy, for each pregnancy.