When COVID took the world by surprise in the winter of 2020, public health experts and families needed time and information to understand the risks posed to our community and for individuals. Last winter, as we adjusted to life with COVID, many parents of young children were faced with a different viral illness that affects almost all children by the age of two. Identified in 1956, respiratory syncytial virus, commonly known as RSV, flooded hospitals as part of the triple-threat tridemic of RSV, influenza, and COVID.
Because RSV has been with us for so long, we know how it behaves. We see it range from the very mild to the very severe. We know that RSV is most worrisome for some high-risk infants, like those with heart conditions or who spent time in the neonatal intensive care unit. But we also know from experience with friends and family that even healthy babies and toddlers with RSV can end up with the wheezing, the shortness of breath, and the dehydration that requires doctors’ visits, late night emergency room trips, or overnight stays in the hospital. Though most babies and toddlers manage well, this unpredictability adds to our worry when we think about RSV.
Connections Between COVID and RSV
Even before COVID exposure notifications were commonplace, RSV notifications happened in childcare settings from mid-fall to spring. Parents were informed that a child in the class had been diagnosed and families were encouraged to be on the lookout for the clear runny nose and low-grade fever that so often appear during the first days of infection with RSV.
Easily spread from one playmate to another and from one family member to another, RSV travels through respiratory droplets – sneezes and coughs and wet baby kisses – and as a fomite, the medical term for germs that stick to and transmit from hard surfaces. Remember when we wiped down our groceries at the start of the pandemic? Scientists now know that for COVID, surface spread was not a factor. For RSV, transmission does happen through solid surfaces that children touch, though the surfaces are more likely toys and restaurant tables – where babies’ faces and hands have free rein – rather than cans of food or toilet paper packages.
Most babies get RSV by two years of age, and most do well with supportive care at home. Saline nose drops, bulb suctioning, and extra feedings are often helpful to keep symptoms at bay while the virus passes, but moderate to severe RSV remains the leading cause of hospitalization for infants in the United States. Devastatingly, 100 to 300 children die from RSV-related illness each year.
New Tools to Prevent RSV
Until now, prevention of RSV has been limited to monthly monoclonal antibody shots with palivizumab, branded as Synagis, which provides short-term immune support against RSV to those infants most at risk of complications. This expensive therapy has many logistical challenges, including multiple clinic visits for families during cold and flu season.
Fortunately, 2023 has seen some exciting steps forward. It seems we are on the cusp of RSV becoming a preventable disease! Three new options are on the horizon:
First: Arexvy is the first vaccine fully approved for RSV prevention in the United States. This vaccine, which will be available for adults over sixty years of age this fall, is especially important for high-risk adults with pulmonary problems, cardiac conditions, and immune deficiencies. People older than sixty suffer from severe RSV disease themselves – with up to 10,000 deaths each year from RSV in people in that age group – and fuel the RSV cycle of infection, passing germs to young infants and others at high risk. This means vaccinating our grandparents can help keep our grandchildren safe and healthy.
Second: All infants could receive a long-acting monoclonal antibody during their first RSV season. This monoclonal antibody, called nirsevimab, is reported to be 80 percent effective at preventing hospitalization due to RSV complications and preventing the lower respiratory tract signs of RSV, like wheezing or bronchiolitis, that are so common and worrisome. Given as early as possible after birth, one shot is effective for five months, about the same duration as a typical RSV season. A second dose is being considered for higher-risk infants entering their second year of life as well.
Third: In May of this year, an FDA advisory committee endorsed a new vaccine intended to prevent RSV in young infants by vaccinating the mother at twenty-four to thirty-six weeks of pregnancy. The vaccine, called Abrysvo, has been shown to effectively prevent severe RSV by approximately 80 percent at three months of age and by approximately 70 percent at six months of age. Additionally, when administered at six months, this vaccine prevented about half of all RSV infections requiring any medical attention at all.
Vaccine Safety and Availability
As always, vaccine safety is evaluated critically. From preliminary data, women who were given Abrysvo experienced minimal side effects, with fatigue, headache and muscle pain most reported. Fever was noted in 2.6 percent of all vaccinated women. One safety concern that will be carefully watched is the possibility of increased preterm birth. Though not reported as statistically significant, a 1 percent increase in preterm birth rate was noted and will be carefully followed if and when the vaccine is approved.
Careful evaluation of real-world data is what keeps all vaccines safe and reliable. In the United States, there is a robust reporting system in place to help identify concerns. Personal reporting systems like the CDC’s COVID vaccination reporting system – called v-safe – could be adopted to provide patient feedback for future vaccines. Between December 2020 and May 2023, over 151 million health surveys were completed, and data from its system has been included in more than twenty scientific reports.
Though any intervention has risks, we know vaccinating during pregnancy is an effective tool to prevent infections in young babies. According to data as far back as 2010, vaccinating mothers against influenza prevents hospitalization in 91.5 percent of infants younger than six months. We also use this approach for the prevention of whooping cough when mothers are given a Tdap vaccination with each and every pregnancy. Finally, vaccination against COVID in pregnancy has been shown to reduce risks from COVID infection in newborns. Widespread use of this strategy against RSV would effectively change the course of this long-endemic illness.
Over the coming months, as these tools become available, you’ll be able to ask your pediatrician, family doctor, and obstetrician for more information. Though it is unclear how monoclonal antibodies will be classified and covered for newborns (if the monoclonal antibody nirsevimab becomes the standard of care), preventative care is widely mandated by the Affordable Care Act, which means vaccines are available to most Americans without cost-sharing.
The hope is that these three advances, each based on well-established, long-used, and successful interventions for other diseases, will soon enable us all to consider RSV a preventable disease. Effective tools are in sight in the prevention of the worst consequences of this seasonal hazard for our little ones.