FDA Advisors Recommend First Vaccine to Protect Babies Against RSV. Here’s What That Means for Parents

By Eline Wiggins

The first vaccine to protect babies from the respiratory syncytial virus (RSV) is one step closer to approval after the Food and Drug Administration’s advisory committee met to discuss the efficacy and safety of the vaccine.

If approved by the FDA later this year, this could be the first vaccine to protect infants from RSV, which is a leading cause of hospitalization for infants. The vaccine would be issued to expecting mothers during the second or third trimester of pregnancy to prevent RSV and prevent severe RSV from birth through six months of age.

The Centers for Disease Control and Prevention is also weighing recommendations for a monoclonal antibody for babies and toddlers, as well as a RSV vaccine for older adults.

Virtually all children get an RSV infection by the time they are 2 years old. RSV is a common respiratory virus that usually causes mild, cold-like symptoms. Most people recover in a week or two, but RSV can be serious, especially for infants and older adults. RSV can also cause severe illnesses such as bronchiolitis and pneumonia. The risk is especially high for premature infants.

Some children require hospitalization, but most do not. Currently, there is no vaccine to prevent RSV infection. To prevent RSV infection, Cook Children’s encourages children to continue health habits learned in the pandemic, including hand hygiene, coughing/sneezing into a tissue and staying home if you or your child feel sick.

There are limited treatments for RSV; most are available only for premature infants, infants with other lung diseases, infants who are considered immunocompromised, or patients with congenital heart disease.

In fall 2022, Cook Children’s experienced an early spike in RSV and influenza A cases. Our Emergency Department and Urgent Care Centers were overwhelmed with patients. By November 2022, our patient census was full across the board due to many patients with flu, RSV and respiratory illnesses. If patients were inoculated with the RSV vaccine, this could help alleviate stress on our health care system by keeping children out of the hospital.

During the FDA’s advisory committee meeting, the discussions were complicated so the recommendations were split to vote on efficacy and safety. They unanimously approved based on the efficacy of the vaccine. However, based on available safety results, the decision was split (10 would approve, 4 would oppose).

The vaccine had serious safety concerns in the elderly patient trials that were submitted with 1 patient out of 2,500 having Guillain-Barre syndrome and another with acute disseminated encephalomyelitis (ADEM), both serious central nervous system diseases. Both diseases occur outside of trials in this population, but they are also known to be rarely related to both vaccines and due to the diseases they help prevent. There are post-marketing studies in place in elderly patients to further evaluate the exact risks of these diseases.

Additionally, a pregnancy trial was in progress but it was paused due to safety concerns. In addition to the diseases noted, there were more preterm births in the vaccine group. These were mostly babies born a week or two early which is generally safe, but due to the trend, the trial was paused while the safety is better assessed.

Nicholas Rister, M.D., of the Cook Children's Infectious Disease team, shares what parents and caregivers need to know.

Why should I consider getting the RSV vaccine? Is it safe?

Right now, the vaccine is only approved for elderly patients over the age of 60. People in this age range should talk with their doctor about the vaccine.

There is an ongoing discussion about making the vaccine available for pregnant women so that the antibodies it induces can be passed to their infants via the placenta. It has been difficult to develop an RSV vaccine for very young infants since they do not react readily to the vaccines that have been developed. However, young infants are the group most at risk for severe and prolonged disease with RSV so providing them protection via their mother is an important opportunity.

The safety questions are the issue here. Right now, the vaccine is not approved for pregnant women so it is not an option. However, the vaccine appears very effective so it may still gain approval in some form once the exact risks are better understood.

Importantly, this is not a vaccine that is going to be mandated for pregnant women. The ethical issues with having a person get a vaccine (the mother) to provide protection for someone else (the infant) and the risks assumed between them is going to make this a more nuanced discussion between OB/GYNs, pediatricians, and families.

How long and how strong is the protection against RSV infection if vaccinated?

Initial results from pregnancy trials showed 82% protection from severe RSV disease from 0-3 months of life and still 69% percent at 6 months of life. While this doesn’t prevent disease or even all severe disease, since RSV is so common in infants and particularly dangerous in preterm infants, this level of protection is very significant and dramatic.

What should parents of toddlers and young children know about the RSV vaccine since, if approved, it would only pertain to pregnant women?

RSV is a very low-risk infection for children outside of the first year or two of life and in younger adults. Until vaccine risks are clarified, there likely will be no push for using this vaccine outside of infants (via pregnant mothers) and elderly adults. Should further evaluation (or a new vaccine) emerge to show minimal risk to getting the vaccine, there may be a role in vaccinating older children to prevent the spread within families to high-risk groups. But, for now, the discussion is likely to stay with pregnant women and older adults.

Why is there a need for the vaccine? How will this impact health care systems?

The Centers for Disease Control and Prevention reports that per year, there are between 58,000 and 80,000 hospitalizations for RSV among children under 5. Because so many children get RSV every year, the actual number of children with severe disease is very high. This leads to a massive use of health care resources each year. That’s why there is so much effort into evaluating the vaccine despite some significant safety questions that need answering.

Go here to view more info about RSV from the CDC.

According to the CDC, those at greatest risk for severe illness from RSV include:

• Premature infants
• Infants, especially those 6 months and younger
• Children younger than 2 years old with chronic lung disease or congenital (present from birth) heart disease
• Children with weakened immune systems
• Children who have neuromuscular disorders, including those who have difficulty swallowing or clearing mucus secretions