Pertussis (Whooping Cough) Making a Comeback. Why? New Vaccine is Less Effective | Pharmaguy's Insights Into Drug Industry News |
Cases of whooping cough in the U.S. have spiked in recent years. The newer vaccine is not as effective as the old one, but it has fewer side effects.

In recent years, there have been several outbreaks reaching numbers not seen since the 1950s. A spike in 2012 sickened 48,277 Americans, and 20 died, most of them infants. There were 13 deaths in 2013 and again in 2014, the last year for which statistics are available.

A recent study from California confirms what earlier reports have suggested: that the newer pertussis vaccine, reformulated to be safer and have fewer side effects than the older version, just isn’t as effective.

The study, by researchers at Kaiser Permanente’s Vaccine Study Center in Oakland, Calif., found that just three years after vaccination with the new vaccine and booster, teenagers had lost virtually all of the vaccine’s protection, and more than 90 percent were susceptible to infection four years after the booster.

Pertussis had never been eradicated. Having the disease does not confer lifelong immunity. But the last time there were more than 40,000 infections in the United States was in 1959. That was down from a high of more than 265,000 infections in 1934. By 1976, the number was down to 1,010 infections in the entire country.

“The levels at which it’s occurring now haven’t been seen in at least 50 years,” Dr. Klein said.