Oxford University researchers have started testing inhaled versions of their COVID-19 vaccines compared to those given by intramuscular injection (Associated Press, Sept 14, 2020). An inhaled vaccine could be more effective than those given by injection because it may cause a stronger local immunity in the throat and nose, which are the primary entryways for the virus. Another advantage would be that inhaled immunization may require significantly lower doses for protection than the injected vaccines. The Oxford researchers have already shown that their ChAdOx1 nCoV-19 (AZD1222) vaccine, now in Phase 3 trials, appears to be safe and effective when given by injection. The inhaled vaccine will be given through a nebulizer and a mouthpiece.
