The United States Food and Drug Administration (FDA) has granted an Emergency Use Authorization (EUA) to Moderna’s COVID-19 vaccine, following a recommendation for its authorization from an independent advisory panel earlier in the week. This makes it the second vaccine to receive EUA authorization for use in the U.S., subsequent to the approval of the Pfizer-BioNTech vaccine last week.

Dr. Anthony Fauci indicated in a recent interview with NBC’s Today show that vaccinations with Moderna’s product may commence as early as “Monday or Tuesday” of the following week. This schedule aligns with the timeframe observed between the Pfizer EUA and the initial vaccinations administered to patients last week.

Similar to the Pfizer vaccine, Moderna’s utilizes mRNA technology. This means the vaccine does not include the actual virus, but rather delivers genetic code that instructs the body to produce a particular protein. This protein closely resembles the one used by SARS-CoV-2, the virus responsible for COVID-19, to bind to and replicate within human cells. The Moderna vaccine prompts the body to generate this protein, which is itself harmless, triggering the immune system to create protective antibodies. The body then retains this immunological “memory” while the vaccine itself degrades naturally over time, resulting in immunity without any lasting components.

The vaccine developed by Oxford-AstraZeneca, which is currently awaiting approval for use in the U.S., employs a different approach, utilizing a modified, non-replicating common cold virus to stimulate the production of the spike protein and generate an immune response. While this method is more established in vaccine development, both the mRNA vaccines from Moderna and Pfizer have demonstrated significant effectiveness based on data from their extensive Phase 3 clinical trials.