The United States will achieve herd immunity in its fight against COVID-19 by April, much sooner than most health officials want to admit, Dr. Marty Makary, a Johns Hopkins University health policy expert and surgeon, argues in an opinion piece for The Wall Street Journal and in an interview Friday.

“There is a 77% reduction in daily cases over the last six weeks,” said Makary. “You, as a scientist, have to ask why. We cannot explain that by vaccinated immunity. We can’t explain it by a sudden change in behavior. It is natural immunity and it’s now over 50% of the population.”