by Paul Joslyn, MD, FACOG
During more than 30 years practicing obstetrics and gynecology, I have often heard my pregnant patients ask some variation of this question: “My doctor has recommended both the influenza vaccine and pertussis (whooping cough) vaccine. Is it safe, and why can’t I wait until I’m not pregnant to get vaccinated?”
In fact, there are many reasons to get vaccinated during pregnancy, including important benefits not only to the mother, but also to her baby.
Influenza is a seasonal viral infection that is especially prevalent in the winter. It is usually a mild illness with cough and fever. But flu can develop into a severe infection such as pneumonia that requires hospitalization, admission to the intensive care unit, and worse.
Pregnant women are 2.4 times as likely to get severely ill with the flu than the rest of the population because of pregnancy-related changes in the immune system, heart and lungs. And according to the Centers for Disease Control and Prevention, maternal flu may even be harmful for a developing baby.
Mothers who are vaccinated have a 40% reduced risk of needing to be hospitalized, and their babies have a 72% lower risk of severe flu, as babies born to mothers who get flu vaccines are protected by their mothers’ antibodies after they are born. This is important, as children less than 6 months old, among all children, have the highest incidence of hospitalization from the flu.
The flu vaccine is an inactivated virus, and there are no adverse fetal effects. Maternal vaccination helps both the mother and the baby for up to 6 months, and babies are routinely vaccinated at 6 months.
Pertussis, or whooping cough, is a bacterial infection that affects babies much more severely than adults.
In adults, the infection is usually mild and self-limited, with cough and fever being the main symptoms, but in a newborn the infection can be much more severe and even life-threatening.
Infants under 1 year old are at the most risk. When the mother is vaccinated in the third trimester, the baby gets protection from her antibodies, which cross the placenta. From 2010 to 2017 in the United States, 3,928 babies under 2 months old were hospitalized with pertussis.
The vaccine is 77% effective at preventing pertussis and 90.5% effective at reducing hospitalization in babies under 2 months of age. Babies under 2 months account for half of all infant hospitalizations for pertussis.
In the past, we waited until after delivery for the Tdap vaccine, which contains pertussis, but studies have shown a much better benefit to getting the shot at 27-36 weeks while pregnant. When given postpartum, the vaccine takes two weeks to become effective, and there are no transplacental antibodies to protect the baby until vaccination at 2 months old. The Tdap vaccine has been around for a long time, and its safety is well-established.
If you have any further questions about vaccines in pregnancy, please don’t hesitate to consult one of the providers at Premier Women’s Care of Southwest Florida. We are here to answer your questions and to provide the best possible care throughout your pregnancy and beyond.