Analysis of respiratory syncytial virus fusion protein from clinical isolates of Korean children in palivizumab era, 2009–2015

Abstract

IntroductionRespiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections among infants and young children. The fusion (F) protein of RSV is a major target for monoclonal antibodies and vaccine candidates. We analyzed sequence polymorphisms of the RSV F protein and investigated palivizumab-resistance mutation in clinical isolates from Korean children in post-palivizumab era. MethodsA review of pediatric patients with RSV infections in Korea from September 2009 to April 2015 was conducted. We performed RSV F gene sequence analysis on positive clinical samples and compared to reference sequences, A2 and 9320. ResultsRSV F gene data were obtained from 60 patients (30 RSV-A and 30 RSV-B), of whom 15 (10 RSV-A and 5 RSV-B) received palivizumab. The nucleotide and amino acid identities of the F gene sequence were conserved between RSV isolates and reference strains. There was no significant difference between isolates from patients who received and did not receive palivizumab. One or more amino acid changes were observed in all RSV-A and 26 RSV-B isolates. Twenty-five variations in RSV-A and 17 in RSV-B were noted. One variation within antigenic site II was noted in a RSV-A isolate; D263N with unknown significance was found in a patient without palivizumab prophylaxis. N276S variation adjacent to antigenic site II was observed in 27 RSV-A isolates. However, no known palivizumab-resistant mutations were found in either RSV-A or RSV-B isolates. ConclusionsThe RSV F gene was highly conserved and no known palivizumab-resistant mutants were found in Korean circulating strains.