Of the ~100 SARS-CoV-2 vaccines currently in clinical trials, only seven are delivered intranasally—despite the nose and mucous membranes being the main site of transmission for this respiratory virus. A new Perspective article in the highly respected publication, Science, explains why intranasal vaccines could be so beneficial against COVID-19.
The highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects the respiratory tract and is transmitted, in part, by respiratory droplets and aerosols. Consequently, unvaccinated people are encouraged to wear masks in public, self-quarantine if symptomatic, and practice social distancing. Despite these precautions, millions are dying. As the pandemic takes its toll, vaccines are once again headline news, notably for the speed of their development and the success of messenger RNA (mRNA) vaccines. Given the respiratory tropism of the virus, however, it seems surprising that only seven of the nearly 100 SARS-CoV-2 vaccines currently in clinical trials are delivered intranasally. Advantages of intranasal vaccines include needle-free administration, delivery of antigen to the site of infection, and the elicitation of mucosal immunity in the respiratory tract.
Meissa's COVID-19 vaccine is included in the article -- read more here.