Pertactin-Negative Variants of Bordetella pertussis in the United States

ECDC comment

​This letter to the editor raises the issue of the adaptation of B. pertussis to vaccine selection pressure as one of the reasons for the increase number of cases of whooping cough reported in several countries. Pertactin is a component of acellular vaccines. The authors analysed the pertactin genes from 12 isolates of B. pertussis cultured from specimens from children hospitalized in Philadelphia during 2011 and 2012. On Western blotting, 11 of the 12 B. pertussis isolates were negative for pertactin.

Pertactin-Negative Variants of Bordetella pertussis in the United StatesCorrespondence. N Engl J Med 2013; 368:583-584February 7, 2013DOI: 10.1056/NEJMc1209369
 
This letter to the editor raises the issue of the adaptation of B. pertussis to vaccine selection pressure as one of the reasons for the increase number of cases of whooping cough reported in several countries. Pertactin is a component of acellular vaccines. The authors analysed the pertactin genes from 12 isolates of B. pertussis cultured from specimens from children hospitalized in Philadelphia during 2011 and 2012. On Western blotting, 11 of the 12 B. pertussis isolates were negative for pertactin. As well as in the U.S., several countries in Europe have seen an increase of the total number of cases (especially in newborns, infants, and children above 8 years of age) in 2012 compared to previous years. The authors recommend that isolates of B. pertussis  from geographically distinct U.S. regions should be evaluated to determine whether our finding is a local event or represents a more widespread shift in B. pertussis strains. An understanding of the epidemiology and virulence of pertactin-negative variants is crucial to developing the next generation of pertussis vaccines.