Could whooping cough vaccine need an update?
CDC looks at why pertussis cases have increased
Every couple of months, we sound the alarm of someone with pertussis, aka whooping cough. This week, parents of students at Cedar Park Middle School were notified that a student there had been diagnosed with pertussis. Last month, folks at the Capitol got a letter that employees might have been exposed to pertussis and the Texas Department of State Health Services was investigating.
The Centers for Disease Control and Prevention released a study in March about its own research into why it is that we're seeing more of this disease, which can feel like allergies or a cold until it turns into the signature cough that sounds like a "whoop" in between coughs. People can cough so much they break a rib or have trouble catching their breath.
It cited more than 48,000 reported cases in 2012. Why so many? For a number of reasons: People have become more aware that it's not just a typical cold and seek medical treatment, lab tests have improved and the vaccine's current formula might have waning protection.
In fact, the CDC tested the historical version of pertussis that it keeps stored and upon which the vaccine was built and the version of pertussis in people who recently had the disease. Researchers found that pertussis has evolved genetically.
Think of it like the flu vaccine, says Dr. Mai Duong, chief of pediatrics at Austin Regional Clinic. Every year the flu changes rapidly from the year before, which is why the vaccine is different each year.
While pertussis and other diseases we currently vaccinate for are not evolving as rapidly as the flu, they can evolve, and we can start seeing a different version emerging.
The study results and the increase in cases mean that the CDC will be looking at the pertussis vaccine as one that might need a new formula.
This research and the potential need for a new vaccine doesn't mean you should skip the current version, though, Duong says.
"It will still protect you even if you get pertussis," she says. "The symptoms are not as long and not as severe."
The vaccine is given at 2 months, 4 months, 6 months, between 15 and 18 months, between ages 4 and 6, and at age 11 or 12. Then adults should get it every 10 years. It's given as a combo vaccine with tetanus and diphtheria.
To protect babies younger than 2 months, pregnant women get it in the third trimester at least two weeks before they are predicted to give birth, and anyone who will be in contact with a newborn should also get it at least two weeks before that contact.
"You want a cocoon around the infant," Duong says.
For infants, the risk is that they stop breathing. They also could be coughing so much that they can't get any food in. Duong helped take care of an infant with pertussis who needed feeding tubes and was on a ventilator.
The other vulnerable population is people who have a compromised immune system, such as people undergoing chemotherapy.
Everyone else should get the vaccine, too, Duong says. "The evidence is there that it's good for the community," she says. "It's protective."
It's herd immunity: The more people who are vaccinated, the less likely the chance of the disease showing up. It's spread by respiratory droplets from a cough.
"The risk for the disease is a lot higher than the risk for the vaccine," she says. The vaccine's risk is a fever less than 102 degrees, muscle soreness, a small reaction where you got the shot such as the skin feeling hot or being swollen.