The FDA has approved the Pfizer-BioNTech, Moderna and Johnson & Johnson COVID-19 vaccines for emergency use authorization. These vaccines had high success rates during clinical trials.
Other COVID-19 vaccines are undergoing clinical trials and some will likely apply to the FDA for approval. All vaccines that receive FDA approval will be covered. These vaccines will have dosage recommendations and will contribute to herd immunity. The provider who gives you the vaccine can tell you if you need a second shot. The Pfizer and Moderna vaccines require two shots, and it is important to get both doses to get the full protective benefit of the vaccines. The Johnson & Johnson vaccine requires only one dose.
Early in 2021, people were unable to choose which vaccine they received. It is unclear whether people will be able to choose which vaccine they receive in the future.