A CDC vaccine advisory group’s recommendations were criticized. | Jason Armond/Los Angeles Times via Getty Images

Giving the vaccine to older people first will save lives. Here’s why it was (briefly) controversial.

Millions of doses of the Pfizer/BioNTech and Moderna vaccines against Covid-19 are being shipped around the United States right now, and millions more are on the way. But there are 330 million Americans, and according to expert estimates, it may be the summer or even the fall before everyone who wants the vaccine can get it.

So who gets to be vaccinated first?

That’s the question that the Advisory Committee on Immunization Practices (ACIP), a panel of medical and public policy experts that reports to the Centers for Disease Control and Prevention (CDC), tackled in its latest guidelines. Under the new guidelines from a meeting on December 20, health care