Abstract
Bordetella pertussis isolates that do not express pertactin (PRN) are increasing in regions where acellular pertussis vaccines have been used for >7 years. We analyzed data from France and compared clinical symptoms among infants <6> http://wwwnc.cdc.gov/eid/article/19/3/12-1475_article.htm] Emerg Infect Dis. 2013 ; 19,3.