People who took Pfizer's COVID-19 trial vaccine are hopeful, but remain cautious

The sight of a British citizen getting a COVID-19 vaccine, made by Pfizer, could not have happened without thousands of worldwide participants in clinical trials.

"I couldn't help think of my own grandparents," said Emma Tumarkin, a University of South Florida student who was one of the Pfizer trial subjects.

Though Tumarkin does not know if she got the real thing or the placebo, she was thrilled when the Food and Drug Administration confirmed Tuesday that the shots are 95% effective.

MORE: Ahead of Thursday meeting, FDA posts positive review of Pfizer's vaccine data

"I hope people see this as a source of optimism and a source of hope," she said.

The Trump administration also said Tuesday that the government has agreed to purchase 200 million doses of Pfizer's vaccine.

President-elect Joe Biden announced his administration would coordinate 100 million vaccinations in its first 100 days.

"We will follow the guidance of science to get the vaccine to those most at risk," said Biden. "That includes health professionals, people in long-term care."

The FDA also said trials have shown that there were no safety concerns in the 38,000 participants that would preclude an emergency authorization, which the Trump administration expects any day.

Steve Wotovich was also in the Pfizer trial and said he felt mild symptoms after having the vaccine.

"My side effects were a little muscle ache, a little fatigue, and it was all controllable by ibuprofen," Wotovich said.

His daughter, Amy, was also in the trial and said she will continue to be cautious.

"To have the opportunity to make a change even on a small level is all you can ask for," she said.

The FDA will meet Thursday to discuss Pfizer's request for an emergency use authorization for its vaccine.

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