Your questions about the coronavirus vaccine, answered

Your questions about the coronavirus vaccine, answered

After more than 300,000 covid-19 deaths and 16 million infections in the United States, the first coronavirus vaccine was administered to U.S. health-care workers on Dec. 14. Public health officials are hoping that at least 70 percent of the population will get one of the vaccines being rolled out so that the nation can achieve herd immunity and stop the virus’s spread. Here are answers to some frequent questions.

How does the Pfizer-BioNTech vaccine work?

The first vaccine authorized in the United States was developed by pharmaceutical giant Pfizer and the German firm BioNTech. It consists of two shots, given three weeks apart.

The Pfizer vaccine is also the first vaccine using messenger RNA technology ever approved for human use by the Food and Drug Administration. It is different from more traditional vaccines, which often use a weakened or dead version of a virus, or a laboratory-generated protein. It uses a synthesized scrap of genetic information that is wrapped in a protective fat layer to keep it from disintegrating. When it goes into cells in the muscle of the upper arm, it contains molecular instructions that tell your cells to create a protein that triggers an immune response to the spike protein on the surface of the coronavirus. This means your immune system will be prepared to eliminate the pathogen if it tries to invade.