Despite high rates of vaccination, pertussis cases are on the rise. Is a new vaccination strategy needed?

Last winter, dozens of teenagers at Harvard-Westlake School in Los Angeles endured the intense wracking bouts of coughing that characterise pertussis. They were part of a resurgence of whooping cough termed an “outbreak” by the media.1

The cases may have been picked up by the media in the context of the anti-vaccination movement, but the whooping cough “outbreak” was not a result of unvaccinated teens. California law requires children to have the pertussis vaccine before the age of 11 or 12, and the school reported that 98% of their student body had been vaccinated, as had all the students who fell ill.

Still, the flurry of media reports had a worried edge. If vaccination rates were high, why were children getting sick?

The Los Angeles County Department of Health, however, remained calm. “We anticipated this,” says Franklin Pratt, medical director of the department’s immunisation programme. California had seen other recent pertussis outbreaks among vaccinated teens.2 Public health officials say that these cases may be a result of the current vaccine, which has fewer side effects than the old version, but also wears off more quickly.

For Pratt, cases like those at Harvard-Westlake are the new normal. In recent years, pertussis outbreaks have increased across the US and UK. There were 48 277 cases of pertussis across the US in 2012, the highest number in recent history. In the same year, the UK declared a whooping cough epidemic, with over 9300 cases in England alone—10 times higher than in recent years. Since then, numbers have dropped, but still remain higher than pre-2012 levels.