A year after the first reported cases of COVID-19 became a pandemic, vaccines are now being rolled out across the United States. If you’ve been able to schedule an appointment through your employer or local health department, you may be wondering “what’s next?”

There can naturally be some concerns when any new vaccine is introduced. The new Pfizer and Moderna vaccines are no different. One of the most common questions is “what are the side effects?”

While most people experience some kind of reaction after the vaccine, the good news is many side effects are mild and manageable.

“I had some moderate arm pain for a couple of days but ibuprofen took it right away,” said Dr. Nainesh Parikh, an interventional radiologist at Moffitt Cancer Center. “The pain bothered me while I was sleeping for a night or two, but by the third night it was gone.”

Parikh was one of the first frontline health care workers to receive the Pfizer vaccine at Moffitt. According to the Centers for Disease Control and Prevention, pain and swelling of the arm where you receive the shot are the most common side effects.

Other side effects include:

• Fatigue
• Headache
• Muscle pain
• Chills
• Joint pain
• Fever

If you do start to experience symptoms after receiving your vaccine, it can actually be considered a positive sign.

“If we get some swelling and little fever, that's the immune system showing us that it's working,” said Dr. Patrick Hwu, president and CEO at Moffitt. “That's how our immune system starts to train itself to fight viruses.”

"If we get some swelling and little fever, that's the immune system showing us that it's working."

- Dr. Patrick Hwu, Moffitt president and CEO

According to the Food and Drug Administration, more people experienced these side effects after the second dose than after the first. If you have pain or discomfort, you should talk to your doctor about taking an over-the-counter pain reliever like ibuprofen or acetaminophen.

Not all of the side effects are caused by what’s inside the vial. Jane Cain is a licensed practical nurse at Moffitt’s Team Member Health Services Center. She’s administered the vaccine to many Moffitt patients and team members and has seen the mental side effects, as well.

“Some of what we’re seeing is anxiety related but it becomes real,” Cain said. “We’re seeing a little bit of flushing and a little bit of rapid heartbeat. When I’m giving the vaccine, I tell people not to panic. You feel the anxiety and it can become worse, but once they sit for a minute it goes away.”

Unlike many common flu shots, the COVID-19 vaccines do not contain the virus in any form, live, dead or weakened.

“This vaccine is made out of RNA,” Hwu said. “Our body makes RNA into proteins. This is RNA that makes proteins that look like the virus. This type of vaccine has been in hundreds of cancer patients with minimal side effects, some swelling, a little fever maybe, but we know this platform is safe.”