Emily Watters is a physician who shares how the mRNA COVID vaccines — known as the Pfizer and Moderna vaccines — work. (Click to enlarge.)

The other option, the single-dose vaccine created by Johnson & Johnson, is explained here (click to enlarge):

Emily Watters is a psychiatrist and can be reached at The Cartoon Shrink. Dr. Watters is a volunteer associate clinical professor at the University of California, San Francisco. She currently works in private practice. She has 14 years of experience working in community mental health settings. She spent several years working in general shelters for the homeless, where she was a leader in developing psychiatric services for people who were homeless. She loves to teach through comics and has developed talks on comics and advocacy, the neurobiology of methamphetamine disorders, splitting in primary care, the cycle of trauma, substances, and homelessness, as well as psychotic disorders in the hospital setting.

All comments here are made in her individual capacity and not on behalf of the University of California, San Francisco, and are not reviewed or approved by the University of California, San Francisco.