Safety and immunogenicity of a plant-derived rotavirus-like particle vaccine in adults, toddlers and infants

Background: This study is the first clinical trial for a parenteral non-replicating rotavirus vaccine developed using virus-like particle (VLP) technology. Methods: This open-labeled, randomized, placebo-controlled trial was conducted in two parts: Part A (a first-in-human study in Australian adults) and Part B (ascending dose and descending age in South African adults, toddlers and infants). In Part A, two cohorts of 10 adults were assigned to receive a single intramuscular injection of 1 of 2 escalating dose levels of the rotavirus VLP (Ro-VLP) vaccine (7 mu g or 21 mu g) or placebo. In Part B, one cohort of 10 adults was assigned to receive a single injection of the Ro-VLP vaccine (21 mu g) or placebo, two cohorts of 10 toddlers were assigned to receive 2 injections of 1 of 2 escalating dose levels of the Ro-VLP vaccine (7 mu g or 21 mu g) or placebo 28 days apart, and three cohorts of 20 infants were assigned to receive 3 injections of 1 of 3 escalating dose levels of the RoVLP vaccine (2.5 mu g, 7 mu g or 21 mu g) or placebo or 2 doses of oral Rotarix 28 days apart. Safety, reactogenicity and immunogenicity were assessed. Results: There were no safety or tolerability concerns after administration of the Ro-VLP vaccine. The RoVLP vaccine induced an anti-G1P[8] IgG response in infants 4 weeks after the second and third doses. Neutralizing antibody responses against homologous G1P[8] rotavirus were higher in all Ro-VLP infant groups than in the placebo group 4 weeks after the third dose. No heterotypic immunity was elicited by the Ro-VLP vaccine. Conclusions: The Ro-VLP vaccine was well tolerated and induced a homotypic immune response in infants, suggesting that this technology platform is a favorable approach for a parenteral non replicating rotavirus vaccine. (C) 2021 Elsevier Ltd. All rights reserved.