US booster shots start, even as millions remain unprotected

President Joe Biden speaks about the COVID-19 response and vaccinations Friday in the State Dining Room of the White House in Washington. (AP Photo/Patrick Semansky)

The U.S. launched a campaign to offer boosters of Pfizer’s COVID-19 vaccine to millions of Americans on Friday even as federal health officials stressed the real problem remains getting first shots to the unvaccinated.