© 2017 Roy Benaroch, MD
Pertussis (AKA “whooping cough”) is a nasty bear of an illness in older children and adults. People with pertussis cough for about 100 days – and it’s a horrible cough that sometimes makes people puke, pass out, or wet their pants. Seriously. Three months of that.
But it’s even worse for little babies, especially newborns, who just don’t have the lung power to expel the mucus. They cough, sure, but a lot of them get encephalitis and seizures, and some of them just stop breathing. So it’s especially important to protect the youngest babies.
Rates of pertussis have been climbing, in part because the newer vaccine that we started using in the 1990s doesn’t seem to give as lasting immunity as the old-school, whole-cell vaccine of earlier days. And as more pertussis circulates in communities, it’s the little babies who suffer the most. Pertussis vaccines are given to babies at 2, 4, and 6 months – and that means they build own protection slowly over the first year. Fortunately, a study published today shows that we can prevent most cases of newborn pertussis – even in babies too young to have gotten the full benefit of their own vaccines.
Researchers from the Kaiser Group of Northern California looked at records of all of the babies born at their facilities from 2000-2015 (those years spanned two big California pertussis outbreaks, in 2010 and 2014.) They hypothesized that a strategy of vaccinating pregnant women against pertussis, recommended since 2011, would help prevent pertussis in their newborns. Since people enrolled in Kaiser get all of their care at Kaiser locations, they could track which babies caught pertussis and they could tell which moms got a dose of pertussis vaccine during pregnancy.
They had a lot of babies to track – about 150,000. 17 of those babies caught pertussis in the first 2 months of their lives, and 110 caught it within the first year. The authors compared the rates of pertussis among babies whose mom got the Tdap (tetanus-diphtheria-pertussis) vaccine during pregnancy versus those who did not.
Of the 17 newborns less than 2 months with pertussis, only 1 had a mom who was vaccinated during pregnancy – working out to a vaccine effectiveness of about 90%. Looking down the road as the babies got older and received their own doses of pertussis vaccine, the effectiveness of maternal Tdap remained strong throughout the first year. There were no signs that maternal vaccination interfered with the effectiveness of the babies’ vaccines.
This is great news – an easy and effective easy way to prevent a potentially devastating disease of young babies. Previous studies have shown that this vaccine is also very safe for both pregnant women and their babies. Keep your babies safe – make sure, moms, you get a dose of Tdap during every pregnancy.