The reasons why second dose of COVID-19 vaccine has worse side effects
More than 55 million doses of the COVID-19 vaccine have been administered in the United States, according to the Centers for Disease Control and Prevention (CDC). More Americans have received the vaccine developed by Pfizer-BioNTech (28 million) than the Moderna-developed vaccine (26 million). About 15 million people have already received a second dose. The only coronavirus vaccine shots approved for use in the U.S. right now are versions from Pfizer and Moderna, each of which requires two shots. It is known that the first vaccine teaches your body how to react to the virus. The second dose has stronger side effects because your body has now been exposed to that vaccine once and your immune system has boosted somewhat so it is more common to see reactions with dose two. The U.S Food and Drug Administration reported the most common side effects are pain in the injection site, fatigue, muscle pain, chills, headache, joint pain and fever. The FDA also reported more people are expe