More about respiratory syncytial virus (RSV)

This page provides a link to PATH's work on respiratory syncytial virus (RSV) and information about the disease and related vaccines.

On the PATH website

RSV disease

  • RSV is the most important cause of viral acute lower respiratory infection (ALRI) in infants and children worldwide and is responsible for over 30 million new ALRI episodes worldwide and up to 199,000 deaths in children under five years old. The elderly are also at risk of severe RSV disease.
  • The virus, which belongs to the Paramyxoviridae family, can cause symptoms similar to the common cold, but can also lead to otitis media (middle ear infection), pneumonia, and bronchiolitis (inflammation of the small airways in the lung). Infection with RSV early in life can increase the chances of developing recurrent wheezing and asthma.
  • In the industrialized world, RSV is the leading cause of child hospitalizations due to ALRI, with up to 125,000 hospitalizations per year in the United States alone. By the age of two, nearly all US children have been infected with RSV at least once.
  • Disease burden in low-resource countries is less understood, but available data indicates that the virus is responsible for a high proportion of childhood ALRI in these settings, particularly in the first few months of life. RSV can also lead to substantial economic hardship in the developing world where hard-to-reach healthcare, hospital costs, and lost livelihoods make caring for the sick particularly burdensome for caregivers, households, and communities.
  • Studies have shown RSV to occur in well-defined seasons during the winter and spring months in countries where the climate is temperate. In tropical climates, data indicate that RSV may increase in prevalence during the rainy season, but these findings are not consistent.
  • RSV is transmissible from person to person and can be spread through inhalation of or contact with nasal secretions from an infected individual via droplets containing the virus that are sneezed or coughed into the air.
  • Since RSV can survive on many hard surfaces for several hours, frequent hand washing and cleaning of hard surfaces can help reduce or stop the spread of the virus.
  • Natural infection with RSV does not provide complete protection against future infection.
  • The drug palivizumab can help prevent RSV disease in high risk infants, but it cannot treat or cure RSV infection that is already serious. Availability, cost, and treatment logistics make its use impractical in resource-constrained settings.

RSV vaccines

  • No vaccine exists today to prevent RSV infection due to an incomplete understanding of the body’s immune response to the virus, which has challenged and delayed RSV vaccine development efforts.
  • Attempts in the 1960s to develop a formalin-inactivated RSV vaccine candidate were hampered by several factors, including lack of protection against infection in infants and children, and an association with younger children experiencing more severe RSV disease when naturally infected with RSV after having been vaccinated.
  • Other types of vaccine approaches, such as live attenuated vaccines and sub-unit vaccines, are currently in the early stages of development to combat RSV.

Related diseases

There are a number of repiratory diseases, all of which affect the lungs and airways, including pneumococcus, RSV, Haemophilus influenzae type b (Hib), and influenza. Learn more about pneumococcus. Learn more about Hib. Learn more about influenza.


Page last updated: October 2011.