Respiratory syncytial virus (RSV) causes an infection that affects the lungs and airways. There is currently no effective treatment or vaccine for RSV infection. Each year, close to 180,000 older adults in the United States are hospitalized with RSV disease, and approximately 14,000 die. Children, particularly during infancy and up to age 5, are also heavily affected by RSV. Each year in the US, approximately 58,000 children are hospitalized, and RSV is the most common cause of pneumonia in children under a year of age.

Around the world, there is an urgent need for a vaccine that can prevent RSV. That’s why Pfizer is working to develop an RSV vaccine for adults, and for pregnant women to protect their infants.

Scientists have been trying to develop a vaccine for RSV for over half a century. Recent research has helped establish a better understanding of the virus. For example, we have learned how an important protein in the virus changes shape, and that the original shape (RSVpreF) causes a strong immune response. Pfizer has applied this scientific advance in its development of an investigational RSVpreF protein-based vaccine that is being studied in several clinical trials for adults ages 60 and over, as well as for expectant mothers in their second or third trimester.

If you or a loved one are considering taking part in one of Pfizer’s RSV vaccine clinical trials, find more information below.