Respiratory syncytial virus (“RSV”) is a significant cause of disease in infants and young children, but is also an important cause of respiratory infection in the elderly, the immunocompromised, and persons with underlying heart or lung conditions.
Recent studies have suggested that the rate of RSV-associated disease may be similar to that of influenza, with comparable rates of infection and severity of illness. Among elderly patients in the U.S., costs incurred as a result of RSV-related pneumonia hospitalizations may conservatively exceed $150 million per year.
RSV Symptoms and Treatment
RSV infection has symptoms similar to other common viral respiratory diseases, including cough, congestion, sore throat, and breathing difficulty. Lower respiratory tract disease is common and, in severe cases, may result in respiratory failure or death. Congestive heart failure and other chronic conditions contribute substantially to poor outcomes following RSV infection.
Treatment for RSV is generally supportive in nature, consisting of supplemental oxygen, intravenous fluids, and bronchodilators. Inhaled and systemic corticosteroids are often prescribed in patients with asthma or chronic obstructive pulmonary disease (“COPD”) – humoral immunity may be diminished with the use of systemic corticosteroids – as a result, they are typically prescribed only in severe cases of disease.
Rates of RSV Infection in the Elderly and At-Risk
RSV is increasingly recognized as a cause of pneumonia and as an important risk factor for persons living with heart or lung disease.
A 2005 study evaluated rates of common respiratory illnesses, including RSV and Influenza A, in healthy elderly patients (≥ 65 years of age) and high-risk adults (with chronic heart or lung disease) over four consecutive winters.
RSV infection developed annually in 3% to 7% of healthy elderly patients and in 4% to 10% of high-risk adults. Among healthy elderly patients, RSV infection resulted in fewer office visits than influenza, however, the use of health care services by high-risk adults was similar between persons infected with influenza and RSV. Among those hospitalized, influenza and RSV infection resulted in similar lengths of stay, intensive care use, and mortality.
RSV infections is particularly problematic for elderly adults living in communal settings. Winter outbreaks of RSV have been widely reported in long-term care facilities and nursing homes – RSV is estimated to infect 5% to 10% of nursing home residents per year, causing death in 2% to 5% of cases.
Estimated Cost of RSV-Related Hospitalizations
A 1999 study that analyzed U.S. hospital discharge data, vital statistics, and Medicare cost data found that 2% to 9% of the 687,000 pneumonia hospitalizations were attributed to RSV. At a cost of $11,000 per hospitalization, the estimated costs of RSV-related pneumonia hospitalizations could reach $150 to $680 million annually.
The impact of RSV infection in adults continues to increase with an aging population, and also with the increased use of immunosuppressive drugs for malignancy and inflammatory disorders. The development of effective therapeutics agents and vaccines for RSV would be beneficial for the elderly and other high-risk adults.
VBI’s RSV Vaccine Program
VBI plans to apply its enveloped virus-like particle (“eVLP”) vaccine platform to develop a novel RSV vaccine candidate. Learn more about our RSV Vaccine Program >>