A randomized phase I trial of intranasal SARS-CoV-2 vaccine dNS1-RBD in children aged 3-17 years.

The intranasal SARS-CoV-2 vaccine dNS1-RBD (Pneucolin®), based on a live-attenuated influenza virus vector, has obtained Emergency Use Authorization in China for individuals aged 18 years and older. Here, we conducted a single-center, double-blind, placebo-controlled, age de-escalation phase 1 clinical trial to evaluate the safety of the dNS1-RBD in children aged 3-17 years (ChiCTR2300068044). Sixty-three participants received 2 intranasal doses of the vaccine or placebo at days 0 and 14. Safety assessments included adverse events/reactions within 30 days and serious adverse events (SAEs) over 12 months. Blood and nasal secretion samples were collected to further monitor blood indices and viral shedding. The vaccine group showed similar adverse reaction rates to the placebo group (39.0% vs 36.4%), with no SAEs related to vaccination. Data suggested that the dNS1-RBD vaccine is well-tolerated in children aged 3-17 years, and warrants further studies on its safety, immunogenicity and efficacy in this population.