Whooping cough cases spike in U.S.

Experts fear that a spike in whooping cough, or pertussis, cases may be related, in part, to waning protection offered by the vaccine.

The U.S. Centers for Disease Control and Prevention reported that, as of mid-August, there have been 23,000 reported cases of whooping cough in the United States, including 13 deaths from the illness. Nearly half of the reported deaths occurred in Texas, according to

"It's a really nasty illness," Dr. Melanie Mouzoon, a pediatrician at Kelsey-Seybold Clinic in Texas, said, reports. "There are more cases now than any time in the United States since the 1950s across the nation."

Health experts believe the reason behind the rise in cases may be a combination of a less robust vaccine, which has been in use since 1991, and an increase in the number of those avoiding vaccination.

Mouzoon said that the vaccine used prior to the 1990s was extremely effective, but caused a large number of side effects, including fever, sore legs and irritability. She suggested that the newer vaccine may not have a long lasting immunity and that the medical community may have to revise its administration recommendations.

Dr. Peter Hotez, the dean of the National School of Tropical Medicine at Baylor College of Medicine and the head of the Texas Children's Hospital Center for Vaccine Development, said that a booster may eventually be recommended.

"We always are learning a lot about new vaccines and sometimes we have to change recommendations," Hotez said, reports. "Vaccination is still the most effective prevention in the United States and globally."