Moderna is already testing the higher dose in a large Phase III study, the final stage, before seeking emergency authorization or approval.
Side effects, which include headache, fatigue, body aches, chills and pain at the injection site, are generally considered to be mild to moderate.
In at least two cases, however, the volunteers had severe reactions.
One developed third-degree fever, which was classified as 102.2 degrees Fahrenheit (39 ° C) or higher, after receiving the lower dose of vaccine. Another developed fatigue is so severe that it temporarily prevents daily activities, Anderson said.
Side effects usually appear soon after receiving the vaccine and resolve quickly, he said.
“This is similar to what many older people will experience with high doses of the flu vaccine,”
Norman Hill, a 65-year-old senior multimedia developer at Emory who took the lower dose of the vaccine, said he felt compelled to participate in the trial after watching the first responders in New York and Washington fight the virus.
“I really didn’t have any side effects,” said Hill, who grew up in the New York area.
Hulme said he was aware that Moderna’s vaccine used a new technology and that there could be a risk of it being adopted, but said “someone has to do it”.