The three primary options for COVID-19 vaccination in the U.S. right now are Moderna, Pfizer, and Johnson & Johnson. Both Moderna and Pfizer are two-dose mRNA vaccines, which is a technology that’s been around for decades and uses lab-developed mRNA to teach cells how to create a protein that will activate the necessary immune response to fight the virus. Think of it like that training montage we often see in movies, where the hero teaches a town how to defend itself from bandits.
Johnson & Johnson’s vaccine is also available as either a substitute for people who can’t or don’t want to take mRNA vaccines and is the more typical kind of formula. It requires a single dose (as opposed to Moderna and Pfizer’s two), and instead of using mRNA blueprints for defense, it uses a weakened or inactive germ to help your body learn how to fight it. Regardless of the version of vaccine you get, the CDC states that your vaccination isn’t “complete” until two weeks after your final dose.
Of the three options and two types of vaccine, the CDC recommends Moderna or Pfizer’s mRNA versions over Johnson & Johnson’s more typical vaccine. All three companies have two additional boosters available, as well.