You may have heard that the Centers for Disease Control and Prevention (CDC) recently recommended a new vaccine for use in the third trimester of pregnancy. Known as AbrysvoTM, the vaccine helps protect newborns against severe cases of respiratory syncytial virus (RSV). RSV is the leading cause of infant hospitalization in the United States, with anywhere from 58,000-80,000 hospitalizations occurring each year among children younger than 5. Even more upsetting is that 100-300 children under age 5 die from RSV every year. With these statistics in mind, this new RSV vaccine is exciting news for infants and their families.
Ava, 24 weeks along with her first pregnancy, contacted the MotherToBaby live chat service early one morning with some questions about the new RSV vaccine. First, she wanted to understand how vaccinating a pregnant person could provide protection for a baby. As a Teratogen Information Specialist, I was happy to answer this question for Ava. I started by explaining that when a person gets vaccinated, their body makes antibodies. These antibodies protect the body against the actual infection if a person is exposed to the virus or bacteria later in life. During pregnancy, the antibodies that a pregnant person makes after being vaccinated can cross the placenta and pass to the developing baby, providing the newborn with some protection against the infection during the first few months of life.
I went on to explain that although the RSV vaccine is new, the idea of getting a vaccine during pregnancy to protect the baby (called “passive immunity”) has been around for some time. The Tdap vaccine, which protects against tetanus, diphtheria, and pertussis (whooping cough), has been recommended for use in pregnancy since 2011. Whooping cough is another infection that can be very serious for newborns, so having protection from birth as a result of maternal vaccination is ideal. The flu shot and COVID-19 vaccine can also pass antibodies to the developing baby during pregnancy. This is great news since newborns can’t get their own flu or COVID-19 shots until 6 months of age and need to rely on passive immunity in the meantime.
Next, Ava had a question about when she should get the RSV vaccine. She had plans to get her flu shot and Tdap vaccine at her next prenatal visit at 28 weeks. She wanted to know if she could get the RSV vaccine at the same time. Although these three vaccines (along with the updated COVID-19 vaccine) can all be given on the same day, the RSV vaccine should be given during a specific timeframe in order to pass as many antibodies as possible to the baby. Experts recommend that the RSV shot be given between 32 and 36 weeks of pregnancy. This allows enough time for RSV antibodies to pass to the baby before delivery.
With this recommendation in mind, Ava decided that her prenatal appointment at 32 weeks would be the perfect time to get the RSV vaccine. She had seen firsthand just how serious RSV can be when her 1-month-old niece was hospitalized with RSV last winter, so she didn’t want to take any chances with forgetting to get the RSV vaccine during her pregnancy.
Before we ended the chat, I mentioned to Ava that there is also a shot called nirsevimab (BeyfortusTM) that can be given directly to babies under 8 months of age. Also known as a monoclonal antibody, this shot is another way to protect infants against severe RSV disease. Most babies do not need nirsevimab if their mom received the RSV vaccine during pregnancy. I suggested Ava talk with her healthcare provider about the pros and cons of both options.
Although having to remember to get another vaccine in pregnancy can feel like just one more thing a pregnant person needs to add to their never-ending to do list, the decision to vaccinate can prevent serious complications from RSV, and possibly even save the baby’s life. Here at MotherToBaby we are happy to go over the current recommendations for vaccines in pregnancy and answer any questions that you may have. Don’t hesitate to call, chat, text, or email with any questions about the RSV vaccine or other exposures during pregnancy. You can also check out our newest fact sheet about this vaccine here https://mothertobaby.org/fact-sheets/respiratory-syncytial-virus-rsv-vaccine-abrysvo/.
Centers for Disease Control and Prevention. 2023. RSV Vaccination for Pregnant People. Available at: https://www.cdc.gov/vaccines/vpd/rsv/public/pregnancy.html
Centers for Disease Control and Prevention. 2023. RSV Surveillance & Research. Available at: https://www.cdc.gov/rsv/research/index.html