Once you get one type of vaccine, will you have to get the same one forever? A vaccine being administered to a patient. (Source: NBC) By Simone McKenny | May 3, 2021 at 7:20 PM EDT - Updated May 3 at 7:20 PM CHARLOTTESVILLE, Va. (WHSV) - More than 45 percent of the population in Virginia have been vaccinated with at least one dose of a COVID-19 vaccine. There have been 237 million vaccines administered across the nation. There have been three main vaccines distributed in the U.S. — the Pfizer, Moderna and Johnson and Johnson vaccines. Johnson and Johnson is a single dose immunization, and Pfizer and Moderna require two doses.