WASHINGTON (AP) — The Biden administration hopes to make getting a COVID-19 booster as routine as going in for the yearly flu shot. That’s at the heart of its campaign to sell the newly authorized shot to an American public that has widely rejected COVID-19 boosters since they first became available last fall. Shots of the the newest boosters could start within days, and they are specifically designed by Pfizer and Moderna to respond to the omicron strain. The U.S. government has purchased 170 million doses and is emphasizing that anyone who wants a COVID-19 booster will get one for free.