Researchers unveiled an intranasal vaccine combining an adenovirus vector and a trimeric subunit protein that enhanced neutralizing immunity against the Omicron variant. Preclinical data described improved mucosal and systemic immune responses—an approach intended to block transmission by inducing local immunity in the respiratory tract. The hybrid vector/subunit strategy aims to address waning protection and variant escape. Developers said the formulation could extend protection against evolving SARS‑CoV‑2 lineages and provide an alternative route of administration to injectable boosters, pending clinical translation and safety readouts.