Some fear boosters will hurt drive to reach the unvaccinated

In this Jan. 15, 2021, file photo, Dr. Yomaris Pena, Internal Medicine Physician with Somos Community Care at a COVID-19 extracts the last bit of Pfizer COVID-19 vaccine out of a vial so as not to waste it at a vaccination site at the Corsi Houses in the East Harlem neighborhood of New York. The number of COVID-19 vaccinations is falling in the U.S. And some experts worry that the decision to give booster doses could end up hurting efforts to get the unvaccinated to take shots at all. (AP Photo/Mary Altaffer, File)