June 25, 2018 – In Game of Thrones, the ominous phrase is “Winter is coming.” The characters don’t know exactly when winter will be back but there are clues out there and a sense of dread. Well, in the public health world we are starting to hear “Pertussis is coming.” Why the concern? Pertussis, often known as whooping cough, is known to come in cycles, generally peaking every 3-5 years. Outbreaks of pertussis were first described in the 16th century and to this day it remains a common childhood disease sometimes with tragic consequences. Before the pertussis vaccine, there were years with over 200,000 cases reported in the United States. That dropped dramatically to less than 3,000 reports per year on average in the 1980’s. Since then, however, pertussis has been making a comeback. In California, in 2010, there were more than 9,000 cases (the most in 60 years). Then 2014 was even bigger. What will 2018 bring? That’s hard to predict but we know pertussis is widespread in the world right now and some areas in the US are starting to report increases.
In the 1990’s, in the United States, pertussis vaccines switched to one called an “acellular” vaccine meaning that the vaccine is made using a part of the bacterium not using the whole cell. While that reduced the side effects of the vaccine, it also reduced the duration of protection. Pertussis vaccines offer good levels of protection within the first 2 years after getting vaccinated but protection decreases or wanes over time. Immunity after natural infection also goes down with time but more slowly.
The current focus of pertussis vaccination is protecting babies. This is because babies are at higher risk for getting pertussis and then having serious complications from the infection. Rachel Farrell, PA-C and Licensed Midwife from Harmony Health Medical Clinic and Birth Center says, “We encourage our pregnant moms to get the Tdap in their last trimester to afford protection to the newborn. Since first shots aren’t until the newborn is 6-8 weeks old, they can be at great risk for pertussis, if exposed. If you’ve ever known anyone, especially an infant, who had whooping cough, you’d surely want to do everything you could to avoid it. It is a horrible disease, deadly in infants.”
The CDC reports that about half of babies younger than a year who get pertussis need hospitalization. Fortunately, getting the Tdap vaccine during each pregnancy, preferably at sometime between 27 and 36 weeks of pregnancy, has been shown to be effective at protecting mothers and their babies. A report published in Clinical Infectious Diseases in 2017 (by authors from the California Department of Public Health and UCLA) looked at pertussis-infected infants born in 2011-2015 and found that infants whose mothers received Tdap vaccine during pregnancy had less severe pertussis, significantly lower risk of hospitalization and intensive care unit admission, and shorter hospital stays.
With pertussis/whooping cough likely rising again soon, this is an important time to talk with your healthcare provider about vaccination strategies especially if you have a baby in the house, or you are pregnant or planning pregnancy. For more information on pregnancy and whooping cough, please see https://www.cdc.gov/pertussis/pregnant/index.html.