According to Our World in Data, the US first breached the weekly average of 1 million doses a day on January 23. Less than three weeks later, on February 11, the country hit 1.6 million a day.

This meets both the goals set by President Joe Biden, who initially called for 1 million shots a day and then later revised his goal to 1.5 million shots a day.

That doesn’t mean the US is in the clear. Many experts argued Biden’s goals haven’t been ambitious enough. To get the US to herd immunity — when enough of the US population is immune so the virus no longer poses a major threat — by the end of the summer, America likely needs to hit an average of 2 million or 3 million doses a day.

Consider the following possibilities, assuming a herd immunity threshold of 80 percent (which could be too low or too high) and all vaccines continue to require two doses (which now seems unlikely):

  • At 1.6 million shots a day, the US would reach herd immunity by mid-December.
  • At 2 million shots a day, the US would reach herd immunity by mid-October.
  • At 3 million shots a day, the US would reach herd immunity by the end of July.
  • At 5 million shots a day (woo!), the US would reach herd immunity by the end of May.

Read the full article about herd immunity in the U.S. by German Lopez at Vox.