INTRODUCTION
RSV, pneumonia, human illness, bronchiolitis, RSV-associated lower respiratory tract disease
VACCINE VIRUS SHEDDING, RESPIRATORY DISEASE, VIRUS, PNEUMONIA, RESPIRATORY SYNCYTIAL VIRUS (RSV), CARDIOPULMONARY DISEASE, ADVERSE EVENTS, DISEASE, KENNEL COUGH, BRONCHIOLITIS
Respiratory syncytial virus (RSV) can lead to serious disease in infants, and no approved RSV vaccine is available for infants. This first in-human clinical trial evaluated a single dose of BLB201, a PIV5-vectored RSV vaccine administrated via intranasal route, for safety and immunogenicity in RSV-seropositive healthy adults (33 to 75 years old). No severe adverse events (SAEs) were reported. Solicited local and systemic AEs were reported by <50% of participants and were mostly mild in intensity. Vaccine virus shedding was detected in 17% of participants. Nasal RSV-specific immunoglobulin A responses were detected in 48%, the highest level observed in adults among all intranasal RSV vaccines evaluated in humans. RSV-neutralizing antibodies titers in serum rose ≥1.5-fold. Peripheral blood RSV F–specific CD4Intranasal RSV vaccine based on kennel cough vaccine component PIV5 is safe and immunogenic in humans.Respiratory syncytial virus (RSV) is the leading global cause of morbidity and mortality in infants due to infection-associated bronchiolitis and pneumonia, especially in those with underlying cardiopulmonary disease (RSV causes both upper and lower respiratory diseases. Recently, RSV prefusion F (preF) protein–based vaccines have been shown to be effective in reducing symptoms of RSV-associated lower respiratory tract disease in elderly (aged ≥60 years) in clinical trials and received approval for elderly (BLB201 is a live viral-vectored candidate RSV vaccine based on a parainfluenza virus 5 (PIV5) encoding the RSV F antigen. PIV5 is a negative-sense RNA virus and replicates in the cytoplasm of infected cells without a DNA phase in its life cycle. PIV5 is a component of the kennel cough vaccine commonly administered by intranasal route in dogs. Vaccinated dogs can shed virus up to 5 days after dosing, exposing humans to PIV5. However, although the vaccine has been used for 50 years, no known human illness has been reported from human exposure to vaccinated dogs (