Vaccines should be required for health care workers and for all students who plan to attend in-person classes this fall — including younger children once the vaccine is authorized for them by the Food and Drug Administration. Employers should also be prepared to make vaccines mandatory for prison guards, E.M.T.s, police officers, firefighters and teachers if overall vaccinations do not reach the level required for herd immunity. Short of a mandate, these workers should be reminded that these vaccines have proved safe and are important not only for their health, but for the health of those they deal with in their jobs... As of March 7 (amazingly, we lack real-time data), just under half of all frontline health care workers had not received a vaccine, according to a survey conducted by the Kaiser Family Foundation and The Washington Post. In part, that was because many workers had not been offered one by their employers. But even more remarkably, 18 percent said they did not plan to get a shot and 12 percent reported being undecided.