As the race for the coronavirus vaccine continues, those in the trials for both Moderna and Pfizer are describing the side effects.
"I'm Jennifer Haller and I'm the first person in the U.S. to trial COVID-19 vaccine," said Jennifer Haller, who is part of the Moderna trial.
Jennifer Haller was injected on March 16 with the experimental vaccine by Moderna.
"My arm was sore the next day. I had two doses of the vaccine 4 weeks apart. Each time my arm was pretty sore the next day but besides that I personally didn't experience any other side effects," said Haller.
In September, California resident, Daniel Horowitz, was injected as part of Pfizer's COVID-19 vaccine trial. The trial is double-blind, so Horowitz is not sure if he received the vaccine or the placebo, but he says his side-effects are similar to those of a flu shot.
"I got a little ache in my muscles, like mm I just don't feel right and it went away after that day," said Horowitz.
In their clinical trials, Moderna points to a graph for side effects, which includes:
UCSF's infectious disease specialist Dr. Peter Chin Hong says these are normal vaccine symptoms.
"25% - 50% of people might feel some mild side effects after their first dose. But, after the second one there may be more people who might feel some of these side effects and they might go away within a day or so," said Dr. Chin-Hong.
So what do both vaccines have in common?
"They take a message through the cell in the body and says 'Hey cell make this protein' and this protein is exactly the thing that is on the surface of COVID and that is what your body is responding to," Dr. Chin-Hong said.
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Both Pfizer and Moderna announced that clinical trials show their vaccines are more than 90% effective with more than 70,000 people on the trials combined.
As to long term side effects, "Usually these occur within two months and so far they haven't had any problems with either the Pfizer or the Moderna vaccines."