Respiratory Syncytial Virus (RSV) Diseases

Abstract

The respiratory syncytial virus (RSV) is an RNA virus that causes annual ARI outbreaks during winter with mild URTI in the general population, but with severe LRTI particularly among young children (bronchiolitis), patients with underlying diseases and people >65 years of age. RSV does not induce a long-lasting protective immunity and repeated infections throughout life are the norm. Basically, all children have been infected by 2 years of age and of those hospitalized, >50% are <3 months and 75% are <6 months of age. The overall CFR is 1/500. For adults ≥65 years, RSV hospitalization rates are 90–250/105. There is no specific therapy, general preventive measures include general hygiene and isolation/separation of patients. A monoclonal anti-F-protein antibody is available for passive immunization of selected high-risk children. It requires monthly injections, comes at a high cost and has limited efficacy (50% against RSV hospitalization). Active immunization failed in the past, probably as the post-fusion conformation of the F-protein was used. Long-acting monoclonal antibodies (for infants) as well as stabilized pre-fusion F-protein vaccines (for immunization of pregnant women, children, older adults) produced on various platforms are in late stages of clinical development.