Scheduled to get a second dose of the COVID-19 vaccine? While some have experienced reactions after their first shot, side effects usually occur after a second jab in the arm — whether with the Pfizer/BioNTech or Moderna vaccines, according to the U.S. Food and Drug Administration. So what should those getting a second dose expect? Should you take a day off from work? People can anticipate some minor side effects, especially with the second dose, according to Dr. Reynold Panettieri, vice chancellor for translational medicine and science at Rutgers University. Minor reactions can last for several days and range from “pain at the injection site, tiredness, headache, muscle pain, chills, joint pain, and fever,” according to the FDA.