Preventing Pertussis Outbreaks

Why So Many Pertussis Outbreaks?

So why is pertussis still a problem? Many teens and adults haven't gotten a Tdap vaccine yet, can still get sick with pertussis, and can infect infants who haven't completed their three dose primary series of pertussis vaccines when they are about six months old. The fact that some parents are refusing vaccines or using alternative immunization schedules likely isn't helping prevent these types of outbreaks of vaccine preventable infections either.

The CDC reports that children who had never received any doses of DTaP (unvaccinated children) faced odds of having whooping cough at least eight times higher than children who received all five doses. And a 2009 study that appeared in Pediatrics reported that "vaccine refusers had a 23-fold increased risk for pertussis when compared with vaccine acceptors, with 11% of pertussis cases in the entire study population were attributed to vaccine refusal." Another article, "Geographic Clustering of Nonmedical Exemptions to School Immunization Requirements and Associations With Geographic Clustering of Pertussis," found that "geographic pockets of vaccine refusal are associated with the risk of pertussis outbreaks in the whole community."

Another problem is that the DTaP vaccine likely doesn't work as well as the older DTP vaccine and likely doesn't work as well as we used to think it did. So instead of efficacy of 84 to 85%, as was once believed, it is likely closer to just 71 to 78%.

Other issues, including a decay in antibody to specific vaccine proteins over time, the possibility of an incorrect balance of antigens in the vaccine that could create a blocking effect, and genetic changes in the B. pertussis bacteria, could also possibly lead to increased vaccine failure rates.

California Pertussis Outbreak

Even though there were high rates of pertussis in 2005, the California pertussis outbreak of 2010 was really a wake-up call that whooping cough was coming back. In fact, it was just an outbreak, it was a full fledge epidemic.

There were 9,154 cases of pertussis in California in 2010, the most in 63 years, and 10 infants died.

Preventing Pertussis Outbreaks

Even if you are not in California, this outbreak should be a reminder of how serious pertussis infections are and the importance of pertussis vaccines. Keep in mind that in addition to completing the DTaP (Diphtheria, Tetanus, and acellular Pertussis) series of shots before starting kindergarten and getting a Tdap booster shot when they are 11 to 12 years old (or when they are older if they missed it), the Advisory Committee on Immunization Practices (ACIP) recommends that adults between the ages of 19 and 64 get a Tdap (Tetanus, Diphtheria, and acellular Pertussis) vaccine if it has been 10 or more years since their last tetanus booster shot.

Adults who will have contact with infants less than 12 months old, including parents, grandparents over 65, child-care providers, and health care workers, should get a Tdap vaccine if they have not had one yet, even if it has been less than 10 years since their last tetanus booster.

Date: 2016-06-12; view: 5