TL;DR: Tdap is a booster vaccine for tetanus, diphtheria, and pertussis. A booster shot is an extra shot that keeps your immunity up. Guidelines suggest getting a booster every ten years. Getting a booster while pregnant can help protect your baby from pertussis, commonly called whooping cough, which can be deadly to babies. Tdap is also recommended as a booster every ten years for the general population.
If you’re pregnant, your clinician will recommend getting the Tdap booster between weeks 27 and 36. Getting a booster shot during pregnancy will allow for the transfer of antibodies to the baby via the placenta, giving them some protection against diphtheria, tetanus, and pertussis when they are born. Getting immunity from a parent is especially important since whooping cough is on the rise.
Getting vaccinated while pregnant may sound scary to you. This is understandable because you’re working so hard to keep your growing child safe. There is a lot of false information floating around that might make it confusing to you. So let’s break down what the Tdap vaccine is and how it can help to protect your baby.
What does Tdap protect against?
You likely got DTaP as a child, which is the stronger version of the Tdap vaccine. The Tdap is the follow-up booster. Tdap has a slightly lower dose of the diphtheria and pertussis vaccine and a normal dose of the tetanus vaccine. Tdap, like DTaP, protects against tetanus, diphtheria, and pertussis. Tetanus is a bacteria that you can get infected with if your skin is punctured by metal. The bacteria can travel up your nerves from the original injury via a process called “retrograde axonal transport.” That allows the bacteria to get into the spinal nerves and cause the symptoms associated with tetanus like muscle spasms, muscle contractions, trouble breathing, and eventually death. If you are infected with tetanus, you can be given an antitoxin to help treat it, but untreated, it can be fatal.
Diphtheria is another bacteria. It can cause the throat to swell up, which is called a “bull neck.” This can cause infected people to have a really hard time breathing. Diphtheria can also cause heart problems, like myocarditis, which is where the heart cells become inflamed and reduce the heart’s ability to pump blood.
Pertussis is commonly known as “whooping cough” because the cough has a very distinctive ‘whoop’ noise. You might have also heard it called the “100 day cough” because it can take a very long time for the symptoms and cough to go away. It is also a bacterial infection. The intense coughing can make it extremely hard to breathe. Pertussis can be very dangerous for babies and the infant death rate with pertussis infection is around 2%.
How does getting a Tdap vaccine during pregnancy protect babies?
The immune system is pretty darn cool! When your body is exposed to a virus, for example, your immune cells play a long game of telephone to activate the steps needed to make antibodies via a set of cells called B-cells. These cells produce antibodies which can stick onto viruses or bacteria and tell your body to get rid of the bugs. Antibodies come in a few different flavors. The two important ones for this discussion are called IgM and IgG. IgM are bulky and are produced early on in exposure to an infection. IgG are smaller than IgM and last for a longer period of time. IgM can’t cross the placenta but IgG can. So when babies are born, between the IgG they get from maternal blood and antibodies in breast milk, they have some immune protection while their own immune system starts figuring things out. By getting a Tdap booster during pregnancy, antibodies can be transferred from parent to baby and help create some immunity against these life-threatening illnesses.
Overall, the Tdap vaccine is safe and important to get while pregnant.
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