Whooping Cough Vaccine Antigen Missing from Bacteria in the United States

A recent study looks at how an antigen in the vaccine for whooping cough is slowly disappearing from bacteria in the United States.

The antigen pertacin, which has been present in almost all isolates of Bordetella pertussis since 2010, is now absent.

"These findings tell us that there is an evolutionary advantage to lacking the protein that may have important vaccine implications," first author Lucia C. Pawloski, of the Centers for Disease Control and Prevention, Atlanta, said via a press release. 

For the study, researchers screened 1,300 isolates dating from 1935-2012 that were obtained from outbreak and surveillance studies. A polymerase chain (PCR) reaction was used in order to identify DNA insertions into the pertacin gene that works to prevent an expression of that gene. Background information from the study notes that there were 267 isolates.

Though the vaccine remains effective thanks to the help of other antigens, there is still a cause for concern regarding the vaccine. 

"This recent and drastic change in response to a particular vaccine antigen highlights the need to continue monitoring the circulating bacterial population to allow us to better predict future potential vaccine antigens and respond to the recent upsurge in pertussis," Pawloski said, via the release. 

The study notes that it's particularly important that pregnant women be vaccinated against pertussis, as infants are at the greatest risk to become fatally ill due to complications from this health issue. 

"After receiving this vaccine, a pregnant woman's body creates protective antibodies and passes some of them to her baby before birth," Pawloski adds. 

However, the study notes that fewer than 10 percent of pregnant women are being vaccinated. 

More information regarding the study can be found via the journal Clinical and Vaccine Immunology.