- Kristen Choi, a nurse who participated in the Pfizer-BioNTech COVID-19 vaccine trial, reported a high fever, nausea, and fatigue after her second shot.
- Her side effects signaled an immune reaction, which is the point of getting a vaccine.
- Choi said getting the vaccine was worth it despite the unpleasant reaction.
- Healthcare systems and governments should support people throughout the vaccination process, experts said.
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A couple hours after getting her second shot in the Pfizer-BioNTech vaccine trial in September, Kristen Choi felt chilled, nauseous, and light-headed.
Choi hadn’t experienced any side effects beyond a sore arm when she received her first injection of the COVID-19 vaccine a month earlier. As a nurse and researcher, she knew that her reaction to the second shot likely meant the vaccine candidate had activated her immune system and was doing its job.
But when her fever worsened throughout the night and spiked at 104.9 °F the next morning, she started to feel scared, she wrote in a JAMA Perspective published Monday.
“After months of all of us screening ourselves for fever as a signal of COVID, I think it was a little alarming at first to find myself with a fever like that,” Choi told Insider. “Once I stepped back and thought about it, probably a few minutes later, it occurred to me that this is actually something that happens quite frequently with vaccines.”
She called the research office as soon as it opened, and the nurse who answered told Choi that reactions after the second injection were fairly common. Choi’s fever went down after she took a Tylenol and drank some water, and all of her side effects were gone by the following morning.
Even after experiencing what may be the worst-case scenario based on reports of COVID-19 vaccine reactions in clinical trials, Choi said it was worth it for a chance at developing immunity against the coronavirus.
"I absolutely think that everyone should get the vaccine," Choi said. "What I experienced, even though it wasn't really pleasant, was transient. It wasn't an emergency, it went away in just a day, and if I had to go back and do it over again, I would do it in a heartbeat."
You can't get COVID-19 from the vaccine, but you might have an unpleasant reaction
Although Choi briefly wondered, "Do I have COVID-19?" when she saw she had a fever, she knew that it's not possible to get the disease from the vaccine.
The top COVID-19 vaccine candidates contain tiny pieces of genetic material, not the coronavirus itself. That's enough information to teach the immune system how to respond to the virus, but not enough to get you sick with COVID-19.
"Our bodies have to activate our immune systems to learn how to fight the virus, which is the whole point of getting a vaccine," Choi said. "And part of that activation means that we might experience signals like a fever, chills, nausea, all the things I experienced."
In the clinical trial of the Pfizer vaccine candidate, most volunteers who got the vaccine experienced some side effects. The most commonly reported reactions were pain at the injection site (84%), fatigue (63%), and headache (55%).
Fevers were less common, with 14% of vaccinated volunteers reported higher-than-normal temperatures. Fortunately, Choi said, having several side effects at once seems to be a rare reaction.
Still, experiencing even one of the side effects can be scary if you don't know what to expect. Choi recommended that healthcare providers be honest and prepare people for the reactions they could have when they get the vaccine.
Supporting people through the vaccination process is just as important as what's in the syringe
Stories like Choi's could deter people from getting the COVID-19 vaccine, especially within the current context of mistrust in government and science, said Bernice Hausman, author of "Anti/Vax: Reframing the Vaccination Controversy."
"It's not just a problem of people's interpretations," Hausman, professor and chair of the department of humanities at Penn State College of Medicine, told Insider. "It's a problem of repairing the lack of trust in the government, in pharmaceutical companies, and in public health."
The most important thing these key players can do is let people know they're going to be cared for, Hausman said. This could come in the form of economic support for those who have to miss work if they feel sick, and Choi also suggested phone lines for people concerned about their side effects.
The fact that the vaccine will be rolled out slowly, with healthcare workers getting it first, could also help instill confidence over time. Federal and local governments have time to create infrastructure to help people through the process, Hausman said, and medical professionals can share their own trust in the vaccine.
"I think it can go a long way with patients to say, 'I've gotten this vaccine. It's something I trusted for myself and for my family, and I think you should get it,'" Choi said. "You don't have to be afraid or worried about those effects. They're a signal that the vaccine is working and your body is learning how to fight the virus."