Moderna Inc’s experimental COVID-19 vaccine, the first coronavirus vaccine to be tested on people in the US appears to be safe and able to stimulate an immune response against the virus, its manufacturer, Moderna announced on Monday. The findings are based on results from the first eight people who each received two doses of the vaccine, starting in March.
Those people, healthy volunteers, made antibodies that were then tested in human cells in the lab and were able to stop the virus from replicating — the key requirement for an effective vaccine. The levels of those so-called neutralizing antibodies matched the levels found in patients who had recovered after contracting the virus. Moderna has said the second phase involving 600 people will begin soon, and a third phase to begin in July involving thousands of healthy people. The FDA gave Moderna the go-ahead 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, said the firm’s chief medical officer Tal Zaks.
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 adverse effect at those doses was redness and soreness in one patient’s arm where the shot was given. But at the highest dose, three patients had fever, muscles, and headaches, Zaks said, adding that the symptoms went away after a day
But the high dose is being eliminated from future studies, not so much because of the side effects but because the lower doses appeared to work so well that the high dose is not needed. “Lower the dose, the more vaccine we’ll be able to make,” Zaks said. Moderna’s stock was up 40% in pre-market trading.