Safety and immunogenicity of a single dose of a JN.1 variant COVID-19 vaccine in previously vaccinated adults: Primary analysis report of a phase 3 open-label trial

BACKGROUND: We evaluated the immunogenicity and safety of a dose of NVX-CoV2705, a JN.1 subvariant SARS CoV-2 rS vaccine, in adults previously vaccinated with authorized/approved COVID-19 vaccines. METHODS: titers for the JN.1 subvariant assessed at Day 28 following study vaccination. Primary safety endpoints include local and systemic solicited adverse events (AEs) up to Day 6 post-vaccination, unsolicited AEs up to Day 28, and treatment-related MAAEs, AESIs, and SAEs through Day 180. Exploratory endpoints also provided additional data for circulating variants. RESULTS: Between October 14, 2024, and October 15, 2024, 66 participants were screened and 60 enrolled. A total of 58 participants were included in the Per-Protocol Analysis Set. GMTs increased from 138.6 (95 % CI: 88.0, 218.2) to 671.4 (95 % CI: 437.0, 1031.6) from baseline to Day 28, respectively. In addition, GMTs increased ≥3.8-fold (GMFR) from baseline (Day 0) to Day 28 for currently circulating or emerging Omicron subvariants JN.1, LP.8.1, KP.2, KP.3, KP.3.1.1, MC.1, XEC, MC.10.1, LF.7, LF.7.2.1, LF.7.7.2, NB.1.8.1, and XFC, with an acceptable safety profile after single dose vaccination. DISCUSSION: A single dose of NVX-CoV2705 induced a rapid and robust anti-SARS-CoV-2 immune response against the Omicron JN.1 and other circulating variants and had an acceptable safety profile. https://clinicaltrials.gov/study/NCT06409663.