In the second year of the COVID-19 pandemic, a lot changed in how the US responded to the virus. By early March, three different vaccines received emergency use authorization from the federal government. A vaccine requirement was also put in place for federal workers and later extended to all private employers larger than 100 employees.
At the same time, governments reduced restrictions on where people could go or what they could do. Many states stopped requiring masks indoors. Large events like concerts and live sports resumed.
