The mRNA vaccines for COVID-19, made by Pfizer/BioNTech and Moderna, are among the most powerful vaccines the world has ever seen. According to clinical trial data, they are more than 94% effective at preventing symptomatic disease, with real-world data bearing out that success. The other vaccine currently available in the U.S., Johnson & Johnson’s Janssen vaccine, uses a viral vector and is also proving its strength. Its efficacy, which is better than seasonal flu shots, is 70% generally and even stronger against hospitalizations and death.
While these are “new” vaccines, the mRNA technology—the brainchild of the Perelman School of Medicine’s Drew Weissman and Katalin Karikó—has been tested in animals for years with excellent results. And the Pfizer/BioNTech and Moderna products have been used in broad circulation for half a year, with companies actively pursuing FDA approval.