This is an opinion article. The WSJ already published an opinion article about COVID, by Mike Pence, about how it will disappear very soon (spoiler: it did not). This one is as much fantasy as the one from Mike Pence. Tor reach 250 m vaccinated end of march, considering there are 16 millions people vaccinated today, means you need to make 11.7 millions dose per day every day starting today. Currently they do 1.5 millions dose per day.
The 15% vaccinated is not correct, currently 4.83% of the US population is vaccinated.