WASHINGTON D.C. — While the COVID-19 cases keep increasing nationwide, the CDC has updated the side effects of getting the vaccine.

As of Dec. 20, 241.9 million people or 72.9 percent of the U.S. population had received at least one dose of a COVID-19 vaccine. Of those, 204.1 million or 61.5 percent are fully vaccinated and more than 60.8 million people have received a booster shot.

The CDC has said that as more people get vaccinated, adults and children may have some side effects from the vaccine, which are normal signs that their body is building protection. The side effects may impact daily activities, but the CDC said they should go away in a few days.

“Serious side effects that could cause a long-term health problem are extremely unlikely following any vaccination, including COVID-19 vaccination,” the CDC said on its website. “Vaccine monitoring has historically shown that side effects generally happen within six weeks of receiving a vaccine dose. For this reason, the U.S. Food and Drug Administration (FDA) collected data on each of the authorized COVID-19 vaccines for a minimum of two months (eight weeks) after the final dose. CDC is continuing to monitor the safety of COVID-19 vaccines even now that the vaccines are in use.”

While the CDC said that the benefits of the vaccine outweigh the potential risks, rare cases of myocarditis, inflammation of the heart muscle, and pericarditis, inflammation of the outer lining of the heart, in adolescents and young adults have been reported after getting the second dose of the Pfizer BioNTech and the Moderna vaccines.

Common side effects include pain, redness and swelling on the arm where the shot was administered and tiredness, headaches, muscle pain, chills, fever and nausea that impact the rest of the body.

The CDC also recommends anyone who has had an allergic reaction to any of the three vaccines should not get a second dose or booster. Side effects after the second shot may be more intense and may also last longer, according to CDC data.

If side effects last longer than a few days, the CDC suggests contacting a health care professional.

“CDC continues to closely monitor the safety of COVID-19 vaccines,” the CDC’s website read. “If scientists find a connection between a safety issue and a vaccine, FDA and the vaccine manufacturer will work toward an appropriate solution to address the specific safety concern.”

Anyone with an adverse side effect or reaction can report it at https://vaers.hhs.gov/.