- Groothuis JR,
- King SJ,
- Hogerman DA,
- Paradiso PR,
- Simoes EA
Purpose of the Study
To assess the safety, immunogenicity, and efficacy of PFP-2 (purified fusion [F] protein) vaccine in a high-risk population of young seropositive children with bronchopulmonary dysplasia (BPD).
Twenty-one children (age >12 months) with BPD and culture or serologically proven respiratory syncytial virus (RSV) infection in a previous respiratory season.
Children were randomized to receive one dose of PFP-2 vaccine or influenza vaccine (placebo). Children were followed for adverse reactions and RSV illness over two respiratory seasons. Sera were obtained for determination of immunoglobulin G (IgG) titers to RSV F protein and neutralizing antibody titers before and 1, 6, and 12 months after vaccination.
Adverse reactions were few. Fourfold F protein rises occurred in 9 of 10 PFP-2 and 0 of 11 placebo recipients. Six PFP-2 recipients had low prevaccination neutralizing antibody titers (<1:450); all had fourfold rises. By 12 months, F protein and neutralizing antibody titers in all 21 children were similar. RSV illness occurred in 6 of 11 placebo versus 1 of 10 PFP-2 recipients (P = .06); 1 placebo child required hospitalization.
PFP-2 vaccine appears safe and immunogenic and may protect children with BPD against serious RSV disease on reinfection.
The development of severe pulmonary disease on primary RSV infection in infants who received RSV-formalin vaccine in previous trials has impeded RSV vaccine development. Studies in animals, the elderly, and patients with cystic fibrosis using the fusion protein vaccine have consistently demonstrated good effect, and thus, this approach offers new hope for prevention of this serious disease.