Pfizer vaccine study volunteers demonstrated what it was like to take part.
More than 43,500 people in six countries participated in the phase 3 study by Pfizer and its partner BioNTech.
On Monday, November 10th, it was announced that the sting was more than 90 percent effective in preventing Covid-19 infection.
The study is double-blind, which means the volunteers didn’t know whether they were receiving the vaccine or a placebo.
However, some participants have spoken publicly about how they think they received the vaccine – and talked about side effects they have experienced.
Among them was Carrie, a 45-year-old from Missouri, United States.
She said signing up for the study was a “civic duty” and she was “very proud” of reports on the vaccine’s effectiveness.
She told the press association: “There are so many people who have had and suffered.
“The thought that we could do something to stop people from suffering, losing family members, that we could get rid of it and return to some sort of normalcy in our lives – that’s a driving factor for me.
“I don’t want anyone else to get sick.”
Carrie, who works in publishing, had her first take in September and her penultimate one last month.
She said she had side effects – headache, fever, and pain all over her body – that were comparable to a flu shot after her first shot and more severe after the second.
Glenn Deshields, an Austin, Texas lobbyist who also believes he received the vaccine rather than the placebo, compared the side effects to “a severe hangover.”
Mr Deshields, 44, said he subsequently scheduled an antibody test by his doctor, which came back positive, and is confident it means he did not receive the placebo.
He said his own immune response to the shot made him confident about the vaccine.
He said, “My grandfather – one of his first memories was the ringing of bells at the end of the First World War.
“It was a terrible war and terrible things were happening and people were just glad it was over.
“In my mind, I felt the same … I had a feeling that it was something like that. Thank god it’ll be over at some point. “
Another volunteer, Bryan, an engineer from Rome, Georgia, said he was “a little proud” to hear the news.
But he said participating in the study was “the least I could do to help” as “many people in America are suffering from the virus unnecessarily”.
Bryan believes he was given the placebo.
He felt no immune response and became ill after receiving both of his shots shortly after his daughter caught it last month.
It ended up trapping its entire family, but everyone recovered.
Bryan, 42, voted for Joe Biden in the US election and believes the situation will improve once the elected president takes office.
“I am embarrassed by the way the US president has dealt with the pandemic,” he said.
“But I’m hopeful now because on top of the good news with the Pfizer vaccine, we have a new president-elect and I’m sure he won’t ignore scientists, he won’t downplay the virus, he won’t make you over people.” funny who wear masks – so together I think it will save many lives. “