COVID-19 Vaccines Have Been Available in the US for More Than a Year—What’s Been Learned and What’s Next?
More than a year has passed since people began receiving the first authorized COVID-19 vaccine in the US. By early January of this year, nearly 210 million people, or two-thirds of the eligible population, had received either 2 doses of an mRNA vaccine or 1 dose of an adenovirus vaccine to protect against SARS-CoV-2 infection. On top of that, 75 million people, or more than a third of those eligible, had received a booster dose.