Respiratory Syncytial virus (RSV)

RSV belongs to the paramyxoviridae family, a group of single-stranded RNA viruses. As with EV and coronavirus, RSV generally causes mild or asymptomatic disease. There are also other respiratory viruses belonging to the paramyxoviridae group, parainfluenzavirus and metapneumovirus. Furthermore, this group comprises the viruses that cause mumps, as well as the highly contagious measles virus which, despite extensive vaccination, causes about 20 million infections and 140,000 deaths each year (https://doi.org/10.1152/physrev.00030.2019). Yet, no evidence is available to suggest that CUR-N399 is effective against other viruses in the paramyxoviriade group except RSV.

Effects, spread and incidence of RSV

RSV is primarily known for causing serious lower respiratory tract infections and pneumonia in young children, but the elderly and other vulnerable populations are at increased risk of complicated infections, too. RSV spreads via large droplets aerosolized by coughing and sneezing, or through contact with infectious secretions, hand contamination and self-inoculation of the eyes, nose, and mouth. RSV occurs mostly in yearly epidemic outbreaks during the winter season in temperate areas and during the rainy season in tropical areas.

“From a global perspective, RSV is a leading cause of pediatric hospitalizations and deaths”

Each year, it has been estimated that, RSV causes about 30 million acute lower respiratory tract infections, about 3.2 million hospital admissions and more than 100,000 deaths. From a global perspective, RSV is a major cause of pediatric hospitalizations and deaths. In adults, RSV accounts for about 5–15% of the pneumonia cases during RSV season and, in the US, 11,000–17,000 adults die each year while tenfold more are admitted to the hospital with respiratory complications. In the US, the annual cost of RSV is estimated to be more than $600 million. It is worth noting that RSV hospitalizations are 16 times more prevalent than influenza hospitalizations.

Treatments for RSV infections

There is currently only one treatment, palivizumab (Synagis), approved for RSV. Palivizumab is a monoclonal RSV antibody approved for the prevention of RSV infections in children with increased risk for complicated RSV infections. Palivizumab is thus limited to a narrow target population. What’s more, it is expensive, which limits the availability of palivizumab to only a fraction of the patients in need of RSV treatment.

There is currently no treatment available for an ongoing RSV infection. For prevention, no vaccine is available. New vaccines and monoclonal antibodies with improved administration schedules for RSV are needed to prevent RSV infections. Also, antivirals and other treatments are needed to ameliorate RSV infections in those affected. A number of RSV therapeutics are currently in development, including a several in late stage.