Jan. 15, 2021 New Jersey is one of only two states that has included smoking among the high-risk medical conditions that make people eligible for the Covid-19 vaccine.

Faced with soaring rates of coronavirus infection and more doses of vaccine in freezers than in arms, New Jersey officials made a calculated choice.

They opened the floodgates of vaccine eligibility on Thursday to about 4.5 million additional residents: those 65 and older and younger people with underlying health problems, including cancer, heart conditions and diabetes — diseases that can lead to severe complications from Covid-19.

As part of the expansion, New Jersey also became only the second state in the country to open vaccinations to another high-risk group — smokers. As is true for all Covid-19 vaccinations in New Jersey, no documentation of an underlying health condition is required.

The announcement came a day after the Trump administration told states to expand eligibility and to quickly use existing vaccine or risk losing future allocations.

But New Jersey’s decision to immediately adopt all of the recommendations by the Centers for Disease Control and Prevention for priority vaccination puts these groups ahead of some essential workers — including teachers. The move has contributed to a sense of confusion and anger among those who now find themselves at the back of the line for inoculation.

It has also expanded competition for shots at a time when many people in the first priority groups continue to have trouble making appointments and navigating the overburdened scheduling systems of vaccine clinics.

“The supply is not sufficient. That’s the challenge,” said Jen Kates, director of global health and H.I.V. policy for the Kaiser Family Foundation, a health policy research organization. “It has to be a calibrated balance. You want people to want to come in to be vaccinated, but you don’t want them to have to wait so long they get frustrated.”

The C.D.C. includes smoking on a list of medical conditions that it recommends be prioritized in state vaccination programs because of the higher risk of serious complications from Covid-19. But to date, only one other state, Mississippi, appears to have authorized vaccinations for people younger than 65 based solely on the criterion that they smoke cigarettes.

On Friday, Gov. Philip D. Murphy called criticism that smokers were jumping the line a “cheap shot” and a “false narrative,” noting that the state is hewing closely to C.D.C. guidelines.