COVID-19 Vaccine: The Potential Side Effects You May Encounter

The two COVID-19 vaccines available now in the U.S. have been proven safe, but there are some notable side effects to keep in mind. As more shots become available, more and more Americans are reporting on how the Pfizer/BioNTech and Moderna vaccines are affecting them. According to a report by Vox, about 16 percent of recipients are experiencing "severe" adverse symptoms soon after inoculation.

Common side effects of both vaccines include pain, headache and fatigue — standard when it comes to shots like the seasonal flu vaccine. However, some recipients are also coming down with fevers and extreme tiredness after getting the coronavirus vaccine, and may even need to take a day or two to rest. Medical professionals say that recipients should take the time they need to recover from the vaccination itself.

"We should anticipate that if you got vaccinated that day, you may not want to go to work," said Peter Hotez of the National School of Tropical Medicine at Baylor College. Another researcher, Yale's Saad Omer, explained that these side effects are a sign that the vaccine is doing its job with the patient's immune system.

"Think about [reactogenicity] as mouthwash — it's hurting while it's working," Omer said. "The key is to prepare people to know this will happen — this may hurt a little, give you a bit of fever — but these are short-term, known side effects that you need to be aware of."

So far, publicity campaigns around these vaccines have mostly focused on persuading Americans that they are safe and convincing people to take them. That's because polls show an alarming number of Americans are nervous about these vaccines, either because of anti-vaccination conspiracy theories rising to prominence in recent years, or because these drugs were approved as quickly as possible under regulatory laws.

However, experts like Dartmouth's Brendan Nyhan suggest that transparency about the vaccines' side effects are also essential to public trust. He and others argue that Americans must know what they are getting into so that they're not alarmed when they feel sick after taking the vaccine.

"Millions of people are going to get this vaccine, and we know huge numbers of people are going to have normal side effects, which are often indicating that the vaccine is working. We want to build trust with people so there are no surprises when that happens," Nyhan said.

The latest information on the vaccines is always available on the CDC's website. Check with state and local resources for updates on vaccine availability in your area.