Why new parents (and almost-parents) need pertussis vaccines

I'm 38 weeks pregnant now. Two weeks ago, my husband and I both got Tdap vaccines — tetanus, diphtheria, and pertussis. This despite the fact that we've both gotten Tdaps relatively recently, within the last six years, thanks to a home renovation lifestyle that involves regular exposure to rusty nails.

So why re-up on the Tdap before the birth of our baby? It's all about the pertussis. Also called whooping cough, pertussis is particularly hard on infants. Pre-vaccine, it killed 4000 Americans every year, and most of them were new babies — and infections are on the rise in this country, so there's actually a reasonable risk of a newborn coming into contact with the bacteria that causes pertussis. But the larger problem is with the pertussis vaccine, itself. It doesn't have the staying power it once did. A little over 20 years ago, we switched the formulation for pertussis vaccines. There were good reasons for doing that — the "new" formula has fewer side effects. But it also doesn't seem to protect people as well for as long. In fact, the protection starts to wear off within a year of vaccination.

There are a couple of links that I wanted to share, related to this topic. First is an interview that infectious disease journalist Maryn McKenna did with two women whose newborns ended up in intensive care with whooping cough infections. It's heart-wrenching, and it was very difficult for me to read. But it's also an important reminder that we aren't talking about babies just getting a little sick, here. Infants aren't vaccinated against pertussis until they're two months old. Meanwhile, their little lungs can't deal with the infection as well as adult lungs can. (And even adults often end up breaking ribs during pertussis coughing fits.)

Natalie would cough for hours on end. You wonder if she’s ever going to take another breath. After 2 ½ weeks, she seemed to be doing better. Then all of a sudden, the day after Halloween, she took a turn for the worse. She was on the highest oxygen level she could have. Nothing was working. She got put on a ventilator and that wasn’t working. Then they decided that they were going to try a more intense ventilator, an oscillator. They also did two full-body blood transfusions where they took the blood out of her body two different times and replaced it with new blood. She was so little that the machines for blood transfusions wouldn’t work, so they had to use a syringe. It took eight hours.

She couldn’t keep up her oxygen levels. They sat my husband and I down and said, “We have one more thing we can do.” They wanted to put her on an ECMO, a heart and lung bypass machine, to let her heart and lungs rest. They said, “Your child is most likely not going to survive.”

The second piece comes from several months ago, when journalist Melinda Wenner Moyer wrote about the new pertussis vaccine, and ongoing efforts to figure out why its effectiveness wears off so quickly and what we can do about that. Anti-vaccination campaigns are part of why pertussis is spreading in the United States. But the new vaccine is another part of that problem. We're still giving kids pertussis boosters on a schedule that worked well with the old vaccine, but leaves them exposed (to both illness and being carriers) with the new version.

... whooping cough rates were not significantly different in vaccinated, unvaccinated and undervaccinated children between the ages of 8 and 12. Kids typically finish their initial vaccine series between ages 4 and 6, and the results suggested that protection starts to wane three years later—a big problem, considering that they don’t get another shot until they’re 11 or 12. “It’s awfully worrisome,” Witt says.

In November 2012, the CDC announced the results of its own analysis of the California outbreak. The agency found that the vaccine’s effectiveness begins to drop after one year, and that five years after the final dose, it provides only 70 percent protection. An Australian study recently reported that kids who were given the acellular vaccine as infants were more than three times as likely to get pertussis between 2009 and 2011 than were those who received the whole-cell version.

No one knows why the acellular vaccine is so ineffective.

Image: Baby being treated for pertussis infection, courtesy the CDC.