To help protect infants from whooping cough, vaccinate during pregnancy

Now that whooping cough is at epidemic levels again in California, state health officials are stressing the value of vaccinating pregnant women as a way to help protect newborn infants, who are most vulnerable to the disease. But few obstetricians have incorporated this approach into their prenatal care, for reasons ranging from lack of familiarity to cost to fear of harming the child.

So far this year, two infants have died in California of whooping cough (pertussis) before they could be first vaccinated against it, at around six weeks of age. Of the 77 infants who've been hospitalized with the disease, just under half were too young to be vaccinated, according to the California Department of Public Health.

Infants can get their first DTaP vaccine – which protects against tetanus, diphtheria and pertussis – at around six weeks of age, but they are not considered fully protected until they have received at least three of the five recommended doses, usually by the time they are six months old. So the health department sees the vaccination of pregnant women -- recommended for the third trimester -- as another way to help protect newborns.

Pregnant women receive the Tdap booster vaccine.

During the last whooping cough epidemic, in 2010, the public health recommendation was to surround infants with adults who’d been vaccinated – a strategy called "cocooning."

RELATED: It's official: There's a whooping cough epidemic in California

But hospitals and clinics found it hard to vaccinate everyone, said Dr. Kathleen Harriman, section chief for the state health department's Vaccine Preventable Disease Epidemiology Section.

"It was difficult for them to do family members because they weren't their patients, so you'd end up having these sort of incomplete cocoons," Harriman said.

After ten babies died in California during the 2010 epidemic, health officials shifted their strategy to emphasize third trimester vaccinations. Experts say that tactic is very effective - when it's followed.

Harriman said her department conducted a survey of 100 labor and delivery hospitals last fall, and the results were disappointing: Just 25 percent of the women surveyed said they had received the vaccine during pregnancy.

Dr. James Cherry, distinguished research professor of pediatrics at the David Geffen School of Medicine at UCLA, blames that low vaccination rate in part on the fact that obstetricians aren't used to immunizing their patients.

"The American Academy of Pediatrics has said we do a great job immunizing children at the right time," Cherry said. "In other specialties, this type of preventative medicine, vaccines in particular, have never been done the way we do it."

RELATED: Vaccine refusals fueled California's 2010 whooping cough epidemic

Dr. Daniel Kahn, an assistant professor at UCLA medical school, said he understands why some obstetricians are reluctant to perform vaccinations.

"You know, there's always obstetrician's fears about doing inadvertent harm to the baby," Kahn said. He added that third trimester vaccinations are as safe for the child as those given after birth.

Health officials say some obstetricians are hesitant to start vaccinating because of the start-up costs and new billing procedures involved.

And for obstetricians who do decide to incorporate vaccination into their practice, Kahn said there's yet another challenge: "There are so many extra steps that need to be taken during a pregnancy that remembering one new thing into the process can be burdensome," he said.

Still, Kahn is optimistic that eventually the whooping cough vaccine will be a common part of pregnancy. He said that's what happened with the flu vaccine, which obstetricians started giving to pregnant women regularly after the 2009 swine flu outbreak.

In the meantime, the state health department says it's stepping up its efforts to persuade obstetricians that the whooping cough vaccine should be a standard part of prenatal care.