RSV/NS2/1313/I1314L vaccine in RSV-seronegative children is safe and immunogenic

Ruth A. Karron, Cindy Luongo, Jocelyn San Mateo, Kimberli Wanionek, Peter L. Collins, Ursula J. Buchholz, and the RSVPed Team

The RSV/NS2/1313/I1314L is an intranasal vaccine that contains two attenuating elements in the RSV strain: deletion of the NS2 gene and deletion of the codon 1313. The deletions are stabilized with the substitution of isoleucine at codon 1314. This vaccine induced an immunogenic response in nonhuman primates. A phase 1 double-blind, randomized, placebo-controlled trial was conducted at the Center for Immunization Research (CIR) between 2013 and 2018 in RSV-seronegative and RSV-seropositive children aged 12-59 months. RSV-seronegative children received a single dose of 10 5 or 10 6 PFU and RSV-seropositive children received a single dose of 10 6 PFU. The authors demonstrated that none of the RSV-seropositive children had a ≥4-fold rise in RSV F serum IgG titer. By contrast, 53% of RSV-seronegative children who received 10 5 PFU, developed RSV neutralizing antibodies and F
IgG responses. In RSV-seronegative children receiving 10 6 PFU, even 80% developed RSV neutralizing antibodies and a similar rise in RSV-F IgG antibodies. This indicates that the RSV vaccine is a proper and genetically stable candidate in RSV-seronegative children, which deserves further clinical evaluation in seronegative children. 

This review was written by Safia Laqqa under the supervision of Louis Bont

Download | Paper of the month November 2019