Respiratory syncytial virus
Respiratory syncytial virus (RSV) infects people of all ages causing similar symptoms to influenza and occurring at about the same frequency.
The virus is highly contagious - virtually all infants under the age of two will be infected with RSV, and reinfection is common. For example, roughly 50% of children will experience two RSV infections by the age of two.
RSV is the most common cause of bronchiolitis and pneumonia in children under one year of age, and according to the World Health Organisation (WHO) is the single most important cause of severe lower respiratory infections in infants and young children. The Centers for Disease Control and Prevention (CDC) state that 25 to 40% of young children will have signs of bronchiolitis and pneumonia during their first RSV infection, and 0.5-2% will require hospitalisation. In particular, RSV can cause severe or life-threatening illness in infants who are born prematurely or who have chronic lung or heart disease. The WHO estimates global annual infection and mortality figures for RSV to be 64 million and 160,000 respectively. In the U.S., estimates put RSV associated hospitalisations at between 125,000 and 250,000 per annum.
RSV can also have serious consequences in the elderly and highly immunocompromised patients such as bone marrow transplant patients. It is estimated that 14,000 elderly and high-risk adults die annually from an RSV infection in the US. RSV is believed to be responsible for more than 177,500 hospitalisations of adults each year at a cost to the U.S. healthcare system that exceeds $1 billion.
RSV enters cells in the lung by using a protein, called a fusion glycoprotein, found on the virus's outer envelope. Biota has discovered small-molecule, orally bioavailable, antivirals known as fusion inhibitors (FI) that specifically target this essential fusion glycoprotein, preventing it from functioning and therefore stopping RSV infection from spreading.