Moderna and Pfizer begin late-stage vaccine trials

NIH and the biotech firm Moderna report the first large study of the safety and effectiveness of a coronavirus vaccine in the United States began on Monday. The study, a Phase III clinical trial, will enroll 30,000 healthy people at about 89 sites around the country this summer.

NIH and the biotech firm Moderna report the first large study of the safety and effectiveness of a coronavirus vaccine in the United States began on Monday. The study, a Phase III clinical trial, will enroll 30,000 healthy people at about 89 sites around the country this summer. One-half will receive two doses of the vaccine, 28 days apart, while the remainder will receive two doses of a saltwater placebo. Researchers will then monitor the subjects, looking for adverse events. The study will also try to find out if the vaccine can avert severe cases of COVID and death; if it can block the infection entirely, based on lab tests; and if just one dose can prevent the illness. Meanwhile, Pfizer announced that it has also begun a late-stage study of a coronavirus vaccine. Pfizer has been working with a German company, BioNTech. That study will also include 30,000 people, from 39 states in the United States, and from Brazil, Argentina, and Germany. The government announced last week that it had reached a $1.95 billion deal to buy 100 million doses of Pfizer's vaccine by the year's end if the trial proves it safe and effective. Moderna said in a statement that it would be able to deliver about 500 million doses a year, and possibly up to a billion doses per year, starting in 2021.