(CNN)The youngest volunteers so far to get experimental coronavirus vaccines have been given their first doses and are now being watched carefully to see if they are experiencing any unusual side effects.
A team at Cincinnati Children's Hospital vaccinated 100 children as young as 12 last week, said Dr. Robert Frenck, who is leading the trial for Pfizer's Covid-19 vaccine at the hospital. "Now we are pausing to watch for reactions to the vaccine. We right now are in a planned pause to make sure that everything is as safe as it can be," Frenck told CNN.
Children as young as 12 are now being vaccinated in Pfizer's Covid-19 vaccine trial. Abhinav, 12, was one of them.
Among the side effects doctors are watching for are lumps, redness or pain at the site of the injection, as well as fever or aches.
Abhinav, 12, is one of the young volunteers. The seventh grader -- whose parents asked that only his first name be used to protect his privacy -- hopes that widespread vaccination will help make it safe for his grandparents to resume visits from India, and for classes to get back to normal at school
"I think everyone at my school would like to get back to normal," Abhinav told CNN. "I really think a vaccine could prevent the spread of the infection. As of now, I probably would request other kids to maybe take it."
Abhinav's school is holding classes in person, unlike many schools across the country. He says desks are spaced far apart with Plexiglass screens in between students. "We wear masks the entire day," he said. "It's sort of weird -- if someone is talking from the other end of the classroom you can't really hear them through the Plexiglass that well."
Abhinav knows he only has a 50% chance of having actually received the vaccine. Half the volunteers in this third and final phase of Pfizer's vaccine are getting placebo, or dummy shot. But he hopes he got the real shot because he believes the vaccine will protect him against infection and that, in turn, will prevent him from spreading the virus to others.
Abhinav's father, Sharat, was thinking more about his child's safety. When asked why he signed Abhinav up for the trial, he said, "I think primarily to protect my son. Then, in the process, because it would help science as well. We felt it was a thing to do."
Sharat, himself a physician at the hospital, volunteered for the Phase 1 test of the vaccine earlier this year and felt confident it would be not only safe for his son, but would prevent the virus from infecting him.
"Currently my arm is feeling pretty good," Abhinav, 12, told CNN.
"I am aware of the side-effects affecting the AstraZeneca vaccine," he said. AstraZeneca's trial was paused for nearly two months in the United States after a British volunteer developed neurological symptoms; the US trial started up again last week.
Frenck said people may be nervous about giving children an experimental vaccine but noted Pfizer's has already been tested in tens of thousands of adults.
"The reason we can use this vaccine in children is that Pfizer has 30,000 adults who have been enrolled and it has safety data from all those people," he said.
Plus, he said, it will be important to vaccinate children against coronavirus if there is to be any hope of controlling the pandemic. They are almost certainly contributing to silent spread of the virus.
"I think the important thing people need to remember is that while adolescents aren't getting as sick as older adults are, it doesn't mean that some kids aren't getting sick and some kids aren't dying," he said.
"We have had 120 kids in the US die from Covid so far."
Pfizer's vaccine does not use any active virus. It uses a small piece of genetic material called mRNA -- an approach originally used to fight cancer. "This is the first time it will be used for an infectious disease," Frenck said.
The vaccine stimulates the body to make antibodies against the spike protein -- the structure the virus uses to attach to the cells it attacks.
"The mRNA does not hang around in the body," Frenck added. "It gets degraded quite quickly."
So far, side effects have been mild. "Some people get some achiness," he said. That is likely the body building its immune response, similar to the achiness caused by a real infection. None of the 400 adults who have received the vaccine in Cincinnati's trials have missed work because of side effects, Frenck said.
Likewise, teens who have volunteered have had mild responses to vaccination. "One child developed a low-grade fever and took a dose of ibuprofen and felt fine," he said.
As for Abhinav? "Currently my arm is feeling pretty good," he said.
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Americans are worried about terms such as Operation Warp Speed and emergency use authorization, and fear vaccines are being rushed out too quickly.
Frenck doesn't think so.
What is happening faster is reporting and record keeping, he said. Reports that would normally take weeks to collate and send in are being done several times a week instead.
