The Food and Drug Administration (FDA) recently approved the first vaccine for pregnant people that can prevent respiratory syncytial virus (RSV) in infants. The vaccine is approved for use at 32 to 36 weeks’ gestation. Getting the single dose injection during this stage of pregnancy passes antibodies onto the baby, which will help protect them during the vulnerable newborn months.
“By getting the vaccination in pregnancy, pregnant people can then protect their infant in the newborn period,” says Torri Metz, MD, an associate professor of obstetrics and gynecology at University of Utah Health. “In the research study of the vaccine, the highest efficacy for preventing RSV in babies was when moms received the vaccine within 90 days before delivery.”
What Is RSV?
RSV is a highly contagious virus that circulates throughout the fall in most of the United States and peaks in the winter. In adults and older children, RSV causes mild, cold-like symptoms that usually pass in a week or two, but it can be very dangerous and even deadly for infants, especially ones younger than 6 months old. According to the Centers for Disease Control and Prevention (CDC), RSV is the leading cause of infant hospitalization in the U.S, with an estimated 58,000 to 80,000 children younger than 5 years old hospitalized every year.
Besides infants younger than 6 months old, RSV can cause severe illness in:
- Premature babies
- Children younger than 2 years old with chronic lung disease (i.e., cystic fibrosis)
- Children younger than 2 years old with a congenital heart disease
- Children with weakened immune systems
When symptoms of RSV first start, they may not be severe and could seem like a common cold. Your child may have a runny nose, cough, and loss of appetite. Very young infants may also experience the following symptoms:
- Drinking less
- Decreased activity
- Irritability
- Apnea (pauses in breathing for more than 10 seconds)
Untreated RSV can cause serious lower-respiratory illnesses like pneumonia and bronchiolitis. See your health care provider right away if your child’s symptoms worsen, or if they are having difficulty breathing or are not consuming enough liquids.
How Does the Vaccine Work?
When a pregnant individual gets the vaccine, which contains an inactivated virus, their body responds and creates antibodies to attack that type of virus. The protective antibodies cross via the placenta to the baby, creating passive immunity for up to 6 months after birth.
“This is an opportunity to protect your baby,” Metz says. “Newborns are very vulnerable and are a high-risk group for RSV infection. By getting vaccinated yourself, you can get protection for your baby in those first couple months when they’re really vulnerable to this type of infection.”
According to the results from the clinical trial, the vaccine was found to be very effective when given to a pregnant individual late in their pregnancy. It reduces the risk of:
- Severe RSV by 90% in the first 3 months of life
- Severe RSV by 76% in the first 6 months of life
- Lower respiratory tract infections caused by RSV by 35%
Are There Side Effects?
The overall clinical trial had 7,000 participants, and no safety concerns were found. About half of the group received a placebo, and there were no differences in pregnancy outcomes in the group that received the placebo versus the group that received the vaccine.
The only reported side effects were ones typically seen with many other vaccines, such as:
- Pain at injection site
- Headache
- Muscle pain
- Nausea
- Low-grade fever
“There will be ongoing assessment and evaluation to ensure safety as more people are vaccinated, but there weren’t any side effects or safety signals that were concerning in the studies that have been done,” Metz says.
Metz recommends taking Tylenol if you experience any of the above symptoms after receiving the vaccine.
If you’re pregnant this RSV season, talk to your doctor about getting the RSV vaccine during the approved window. You can breathe a little easier knowing your infant will be protected against this contagious virus.