Like all new drugs, the COVID-19 vaccines that have been authorized in Western countries come with some safety concerns and side effects. Many people who ve received the first two shots deployed, one from Pfizer and BioNTech and another from Moderna, have experienced fever, headache and pain at the site of the injection. These side effects generally disappear quickly. As many as 10 people have had a serious allergic reaction, called anaphylaxis, to the vaccines.
1. What is anaphylaxis?
The body fights foreign invaders through a variety of mechanisms that include making protective proteins called antibodies, releasing toxins that kill microbes, and marshaling guardian cells to battle the infection. As in any conflict, sometimes the effort to repel an infection can itself be damaging. In rare cases, it can produce runaway inflammation and swelling of tissues in a serious allergic reaction called anaphylaxis. As much as 5% of people in the U.S. have had such a reaction to various subs