Human respiratory syncytial virus (RSV)

Human respiratory syncytial virus (RSV) infects the lower respiratory tract of humans, causing the fusion of infected cells into syncytia (hence the virus name).

The virus is spread by direct contact with infected secretions and transmission through objects (fomites).

RSV is prevalent worldwide, with nearly all humans being infected by the age of two. Most infections result in mild, cold-like symptoms, but 1-2% of cases can progress to more severe conditions such as bronchiolitis or pneumonia, often necessitating hospitalisation. 

Repeated infections can occur in immunocompromised adults and in the elderly. Annual epidemics occur during the winter months in temperate climates and during the rainy season in tropical climates. 


RSV belongs to the family Paramyxoviridae (which includes viruses such as measles and mumps), genus Pneumovirus. It's single stranded RNA genome is contained in a capsid and envelope. RSV is closely related to bovine RSV.

Clinical signs

RSV causes infections mainly during infancy and childhood, although infections can occur in the elderly and adults that have weakend immune systems.

Clinical Signs:

  • Runny nose
  • Decrease in appetite
  • Coughing
  • Sneezing
  • Fever
  • Wheezing  
  • Irritability
  • Decreased activity
  • Breathing difficulties
  • Bronchitis
  • In severe cases death

Pirbright's research on respiratory syncytial virus

RSV causes 200,000 deaths worldwide per year in children under the age of five and there is currently no vaccine. However, work done at the Institute has shown a new type of vectored vaccine provides immunity against bovine respiratory syncytial virus, a closely related virus in calves, giving strong evidence that a similar type of vaccine could work in humans.


Find out more about RSV at Public Health England.


* Image by Dr. Craig Lyerla courtesy of Public Health Image Library (PHIL)

Research papers

Thakur N, Conceicao C, Isaacs A, Human S, Modhiran N, McLean R K, Pedrera M, Tan T K, Rijal P, Townsend A, Taylor G, Young P R, Watterson D, Chappell K J, Graham S P, Bailey D (2020)

Journal of General Virology early view
Jobe F, Simpson J, Hawes P, Guzman E, Bailey D (2020)

Journal of Virology early view
Riffault S, Hagglund S, Guzman E, Naslund K, Jouneau L, Dubuquoy C, Pietralunga V, Laubreton D, Boulesteix O, Gauthier D, Remot A, Boukaridi A, Falk A, Shevchenko G, Lind S B, Vargmar K, Zhang B, Kwong P D, Rodriguez M J, Duran M G, Schwartz-Cornil I, Eleouet J F, Taylor G, Valarcher J F (2020)

Vaccines 8 (2) , 231
Ren J, Nettleship J E, Harris G, Mwangi W, Rhaman N, Grant C, Kotecha A, Fry E, Charleston B, Stuart D I, Hammond J, Owens R J (2019)

Molecular Immunology 112 , 123-130
Leemans A, Boeren M, Van der Gucht W, Pintelon I, Roose K, Schepens B, Saelens X, Bailey D, Martinet W, Caljon G, Maes L, Cos P, Delputte P (2018)

Viruses 10 (8) , 426
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