How the US hit its vaccine stride

With an average of 3.1 million doses of Covid-19 administered each day, the United States is on pace to hit another vaccination milestone: Half of adults in the country are expected to have received at least one dose of the vaccine by the end of this week.With an average of 3.1 million doses of Covid-19 administered each day, the United States is on pace to hit another vaccination milestone: Half of adults in the country are expected to have received at least one dose of the vaccine by the end of this week.