Live-attenuated Respiratory Syncytial Virus Vaccines: Time for the Next Step

• Published in: American journal of respiratory and critical care medicine Vol. 203; no. 5; pp. 538 - 539
• Main Authors: Billard, Marie-Noëlle, Bont, Louis J.
• Format: Journal Article
• Language: English
• Published: United States American Thoracic Society 01.03.2021
• Subjects: Child; Child, Preschool; Disease prevention; Humans; Immunization; Pediatrics; Respiratory diseases; Respiratory syncytial virus; Respiratory Syncytial Virus Infections - prevention & control; Respiratory Syncytial Virus Vaccines; Respiratory Syncytial Virus, Human - immunology; Vaccines; Vaccines, Attenuated
• ISSN: 1073-449X; 1535-4970; 1535-4970
• DOI: 10.1164/rccm.202009-3431ED

Dr. Karron and colleagues have previously made several attempts to develop a live-attenuated vaccine against respiratory syncytial virus (RSV) to protect children against one of the most common severe diseases during childhood. They have performed as many as seven phase I trials with different intranasal vaccine candidates. Here, they describe a pooled analysis of these early stage trials among 241 children aged 6-24 months. The authors took advantage of the postvaccination surveillance of acute respiratory infection used to monitor the occurrence of enhanced RSV disease in vaccine recipients to assess the overall vaccine efficacy and key immunogenicity endpoints. While analyzing these trials, they distinguished these vaccines into more and less immunogenic vaccines based on induced serum-neutralizing antibodies. Four vaccines that induced at least a fourfold increase in neutralization of the vaccine recipients were referred to as "more promising" vaccines, in opposition to "less promising" ones. Pooling data from trials with these more immunogenic vaccines, vaccine efficacy against RSV-associated medically attended respiratory infection was 67%, which suggests these vaccines might indeed hold a promise for RSV-naive children.