More pregnant women getting whooping cough vaccine

(Reuters Health) - - Babies are much less likely to get whooping cough if their mothers get vaccinated against the potentially fatal respiratory infection during pregnancy, and a U.S. study finds that a growing number of women are starting to follow this advice.

The bacterium Bordetella pertussis causes whooping cough, which gets its nickname from the sounds patients make as they gasp for air during intense coughing fits. Pertussis is highly contagious and easily spread when an infected person coughs or sneezes. About half of babies under age 1 year who catch pertussis require hospitalization for serious complications like pneumonia or brain disorders.

About 49 percent of pregnant women in the U.S. got the Tdap booster vaccine against tetnanus, diphtheria and pertussis last year, up from just 27 percent in 2014, the study from the U.S. Centers for Disease Control and Prevention (CDC) found. The CDC first recommended this vaccine for all pregnant women in 2013.

“While we are encouraged to see Tdap vaccination is becoming a routine part of prenatal care, one out of two babies are born without protection from whooping cough,” said Carla Black, a researcher with the CDC’s Immunization Services Division who worked on the study.

“The best way to protect babies from whooping cough is to get a Tdap vaccine during the third trimester of each pregnancy,” Black said by email. “Getting Tdap vaccination while pregnant helps protect babies during the critical time between birth and 2 months old, the age when they are old enough to begin getting their own whooping cough vaccines.”

Women were most likely to get the Tdap vaccine when a doctor or nurse recommended it and offered to give them the shot, the study found. About 70 percent of women got vaccinated under these circumstances, compared with just 1.4 percent of women who were not told to do this by their health care provider.

When providers told patients to get the vaccine but didn’t give it to them, about 31 percent of the women were vaccinated, the study also found.

Roughly 13 percent of women who didn’t get the vaccine said they were concerned that it was unsafe for their baby, and another 5 percent of women were worried the vaccine might be unsafe for them.

“From a safety perspective, there’s good data that tells us it’s safe for both mother and baby, with the majority of reported side effects being a sore arm after the vaccine,” said Dr. Kerrie Wiley, a public health researcher at The University of Sydney in Australia who wasn’t involved in the study.

The study confirms something doctors have long known about vaccines: that patients are much more likely to get their recommended shots when doctors tell them to do it and then have a dose ready to give them, Wiley said by email.

“Pregnancy is such a busy time, there’s so many things expectant mothers need to remember, and many women in our research spoke about information overload - having to remember appointments, which foods to avoid and all those other recommendations that come with finding out they’re pregnant,” Wiley said. “It’s about helping put recommended vaccines on their pregnancy radar.

Until recently, there was still some concern that the Tdap vaccination wouldn’t provide sufficient protection for babies, noted Dr. Yvonne Maldonado, chief of pediatric infectious diseases at Stanford University School of Medicine in California.

“Recent studies have demonstrated that there is good protection against pertussis among young infants by maternal Tdap,” Maldonado, who wasn’t involved in the CDC study, said by email.

“Better education of pregnant women and their providers would be very helpful in increasing maternal Tdap vaccination,” Maldonado added.

To assess vaccination rates, researchers conducted an online survey in March and April of 2016 of women 18 to 49 years old who were pregnant at any time since August 1, 2015. The survey included about 2,100 women. Researchers followed similar methods to collect data on vaccination rates for 2014 and 2015.

SOURCE: Centers for Disease Control and Prevention, online June 1, 2017.