PATH’s Center for Vaccine Innovation and Access

Respiratory syncytial virus

Advancing hope against infant respiratory illness

Photo: PATH/Gabe Bienczycki

Photo: PATH/Gabe Bienczycki

Respiratory syncytial virus (RSV) is a leading cause of infant respiratory infections and hospitalizations worldwide and a significant (and underreported) cause of child deaths. RSV causes more than a quarter or respiratory deaths before five years of age, killing nearly 120,000 children each year. Almost all of these deaths occur in low-resource countries, mostly in the first six months of life. Annually, it causes more than 30 million respiratory infections in children worldwide.

RSV produces symptoms similar to those of the common cold, but infection can also lead to serious complications like pneumonia and bronchiolitis (inflammation of small airways in the lungs). RSV can also make infants more vulnerable to pneumonia caused by other pathogens (like pneumococcus) and may be linked to long-term effects like asthma.

RSV is also associated with economic hardship. This is particularly true in low-income settings, where hard-to-reach health care services, high hospital costs, and lost income add to the burdens placed on already-stretched families and health systems. Economic hardship and the resulting lack of access to care also increases poor health outcomes from RSV disease in these settings.

Status of current RSV prevention measures

RSV’s impact remains pervasive in large part because the toolkit for preventing the illness is incomplete. A particularly critical gap is that no RSV vaccine exists. The tool palivizumab (a neutralizing monoclonal antibody) can help prevent RSV disease in high-risk infants, but it cannot treat or cure already-serious RSV infections. The monthly dosing required makes it an expensive and impractical option in low-resource settings. Additional interventions that are well-suited for use in even the poorest regions of the world are urgently needed to save newborn lives and keep millions out of the hospital.

Preparing for incoming RSV interventions

Recent acceleration in RSV vaccine development could bring groundbreaking vaccines within reach in a few years. Promising approaches include vaccines designed to protect infants and mothers through maternal immunization. Vaccinating women during pregnancy can heighten a mother’s immunity and promote the transfer of antibodies to her developing fetus, protecting the baby for the first few months after birth. In addition to maternal vaccines, more affordable monoclonal antibodies that can be given to newborns at birth are also in development and could provide protection in early life.

We are collaborating across sectors to create an enabling environment for forthcoming interventions so that, when they are available, the global health community is poised to use and make them accessible, especially in low- and middle-income countries. Our work includes assay standardization for testing RSV vaccines in consistent ways, and conducting analyses to inform the RSV vaccine investment case.

In collaboration with the World Health Organization, we are also coordinating the Advancing Maternal Immunization (AMI) collaboration with a current focus on RSV. AMI is bringing together diverse stakeholders from across immunization and maternal, newborn, and child health programs to identify viable pathways for enabling informed decision-making, rapid launch, and uptake of maternal vaccines, particularly in low- and middle-income countries.

RSV vaccine and monoclonal antibody snapshot

To support the scientific community, we are also maintaining an RSV vaccine and monoclonal antibody snapshot to provide a quick view of the various RSV prevention approaches in development worldwide. You are welcome to use the document, but we ask that you acknowledge PATH. This snapshot is updated every six months. Please email with any additions or changes. (See PowerPoint and PNG versions.)

Additional resources