"Despite the high success of the current COVID-19 vaccines, there are several limitations, including their reduced effectiveness against SARS-CoV-2 VoCs, short duration of protection, inability to induce a mucosal immune response to protect the airways, and high cost of production or distribution (11, 12). Therefore, there is an urgent need to develop the next generation of intranasal COVID-19 vaccines which induce durable and broadly protective immunity, both in the airways and systemically."