Vaccine Candidates Begin All-Important Trials

Moderna’s vaccine candidate began its final phase 3 clinical trial yesterday—the first US vaccine to reach that milestone, MSNBC reports. 

• The vaccine, developed in partnership with the NIH, uses messenger RNA to train the immune system to target the spike protein on the coronavirus’s surface that helps it invade cells.


• We’ll get a progress report once the first 50 cases of COVID-19 among the participants appear.


• Pfizer also began Phase 3 testing of its vaccine candidate on human volunteers yesterday, working with a German company, BioNTech, The New York Times reports. An Oxford viral vector vaccine has also entered the pivotal Phase 3; Nat Geo has that story.


• What these trials won't be able to tell us: How long immunity might last.