These people, healthy volunteers, made antibodies, which were then tested in human cells in the laboratory and able to prevent the virus from replicating – the most important requirement for an effective vaccine. The levels of the so-called neutralizing antibodies were consistent with the levels found in patients recovering from the virus. Moderna has said that the second phase, involving 600 people, will begin soon, and a third phase, beginning in July, involving thousands of healthy people. The FDA gave Moderna the globe for Phase II earlier this month.
If those trials go well, a vaccine could be available for widespread use by the end of this year or early 2021, the company’s chief medical officer Tal Zaks said.
Three doses of the vaccine were tested: low, medium and high. These initial results are based on tests of the low and medium doses. The only side effect of these doses was redness and tenderness in a patient’s arm where the shot was given. But in the highest dose, three patients had fever, muscle and headaches, Zaks said, adding that the symptoms disappeared after a day.
But the high dose is removed from future studies, not so much because of the side effects, but because the lower doses seemed to work so well that the high dose is not necessary. “Lower the dose, the more vaccine we can make,” Zaks said. Moderna’s share rose 40% in pre-market trading.