Babies born to women who receive the whooping cough vaccine prior to becoming pregnant may be better protected against the disease compared with those whose mothers were vaccinated later, a new study from Australia suggests.
In the study, vaccination before pregnancy cut the risk that a baby would develop whooping cough by about half.
The researchers looked at 217 babies ages 4 months and younger who had whooping cough (also called pertussis), and compared them with 585 healthy infants born at the same time in the same area.
They found that a similar percentage of mothers in both groups had received the vaccine — 77 percent of the mothers of the healthy babies, and 75 percent of moms whose babies had whooping cough had been vaccinated.
However, 41 percent of the moms of healthy babies had been vaccinated at least four weeks before their infant became sick, whereas only 27 percent of mothers whose babies had whooping cough had been vaccinated at least four weeks earlier.
Moreover, 26 percent of the moms of healthy babies reported they were vaccinated before their baby was born, whereas only 14 percent of mothers whose babies had whooping cough said they had been vaccinated before delivery.
In this program, "there was no vaccination during pregnancy, so if a woman said they had it before birth, this meant before pregnancy," said Dr. Helen Quinn, a researcher at the National Centre for Immunisation Research & Surveillance of Vaccine Preventable Diseases.
In the study, vaccination before pregnancy lowered a baby's risk of developing whooping cough by 52 percent, Quinn told MyHealthNewsDaily.
Most deaths from whooping cough occur in children under 3 months old, according to the Centers for Disease Control and Prevention (CDC).
A previous study showed that women's bodies don't start to produce antibodies against whooping cough until about two weeks after they receive the vaccination.
In the new study, infants living in larger households and those who were less well-off were more likely to develop whooping cough, and those who were breast-fed were less likely to become sick, the researchers said.
The finding "suggests that vaccination as part of pre-pregnancy planning would have the greatest impact on whooping cough infection," Quinn said.
An advisory panel for CDC recommended last year that women should be vaccinated against whooping cough every time they become pregnant.
The new study was presented at an infectious disease researchers' meeting in Canberra, Australia.
Pass it on: Babies may be better protected against whooping cough if their mothers receive the vaccine prior to becoming pregnant.