At a news conference on Thursday last week, Dr. Yves Léger, the district medical officer of health for the Moncton region, said vaccination efforts have been ongoing, admitting that “the vaccine isn’t perfect, but one of the best measures we have,” according to CBC News.
There are now 36 confirmed cases of whooping cough in the Moncton region, said Dr. Leger, adding, “Cases were spreading out within the region, which at that point is when I decided to declare it an outbreak.” He told CTV News the cases seem to jump every three to five years.
But while whooping cough, or pertussis, as it is called may be cyclic, other disturbing trends are being seen in the re-emergence of this bacterial disease. After the pertussis vaccine was introduced in the 1940s, there was a dramatic decrease in whooping cough cases over many decades. But by 2000, health officials started seeing an increase in yearly pertussis figures.
CanTech Letter reports that William Schaffner, a professor at the Vanderbilt University School of Medicine says the anti-vaccine movement has played a smaller role in the reemergence of pertussis than it has on measles. He points out that the measles vaccine is 80 to 85 percent effective, and only requires one shot, where the pertussis vaccine requires multiple injections.
More disturbing is the ineffectiveness of today’s pertussis vaccine. Schaffner cites a study published by the Food and Drug Administration in November 2013. In animal studies, it was found that while the pertussis vaccine kept vaccinated baboons from getting sick with whooping cough, it also made them “silent carriers” able to infect others. The study concluded this could apply to humans.
Additionally, it seems the pertussis bacterium is mutating says CDC scientist Lucia Pawlosk. The mutation in a key protein called pertactin, used to make the vaccine, was first noticed in 1994. The changes in the protein were again noticed in 2000. Recent tests, however, have found the “mutations in 60% of whooping cough samples,” Pawloski says.
