Been shouting into a hurricane about this for two years: intranasal vaccines. Intramuscular vaccines do not prevent spread or replication of Covid in the upper

Been shouting into a hurricane about this for two years: intranasal vaccines. Intramuscular vaccines do not prevent spread or replication of Covid in the upper respiratory airways. Intranasal vaccines do. They are slightly more expensive, and slightly more difficult to ship in large quantities, both only slightly.