In North Carolina, the nation’s leading tobacco producer, any adult who has smoked more than 100 cigarettes in their lifetime can now be vaccinated against covid.

In Florida, people under 50 with underlying health conditions can get vaccinated only if they have written permission from their doctor.

In Mississippi, more than 30,000 covid vaccine appointments were open Friday — days after the state became the first in the contiguous United States to make the shots available to all adults.

In California — along with about 30 other states — people are eligible only if they are 65 or older or have certain health conditions or work in high-risk jobs.

How does any of this make sense?

“There is no logical rationale for the system we have,” said Graham Allison, a professor of government at Harvard University. “We have a crazy quilt system.”

Jody Gan, a professional lecturer in the health studies department at American University in Washington, D.C., said the lack of a national eligibility system reflects how each state also makes its own rules on public health. “This hasn’t been a great system for keeping, you know, the virus contained,” she said.

The federal government bought hundreds of millions of doses of covid vaccines from Pfizer, Moderna and Johnson & Johnson — as well as other vaccines still being tested — but it left distribution largely up to the states. Some states let local communities decide when to move to wider phases of eligibility.

When the first vaccines were cleared for emergency use in December, nearly all states followed guidance from the federal government’s Centers for Disease Control and Prevention and restricted use to front-line health workers and nursing home staffs and residents.

But since then states have gone their own way. Some states have prioritized people age 75 and older, while others have also allowed people who held certain jobs that put them at risk of being infected or had health conditions that put them at risk to be included with seniors for eligibility. Even then, categories of jobs and medical conditions have varied across the country.

As the supply of vaccines ramped up over the past month, states expanded eligibility criteria. President Joe Biden promised that by May 1 all adults will be eligible for vaccines and at least a dozen states say they will beat that date or, as in the case of Mississippi and Alaska, already have.

But the different rules among states — and sometimes varying rules even within states — created a mishmash. This has unleashed “vaccine jealousy” as people see friends and family in other states qualify ahead of them even if they are the same age or have the same occupation. And it has raised concerns that decisions on who is eligible are being made based on politics rather than public health.

The hodgepodge mirrors states’ response overall to the pandemic, including wide disparities on mask mandates and restrictions for indoor gatherings.

“It’s caused a lot of confusion, and the last thing we want is confusion,” said Harald Schmidt, an assistant professor of medical ethics and health policy at the University of Pennsylvania.

As a result, some Americans frantically search online every day for an open vaccine appointment, while vaccines in other states go wanting.

The assorted policies have also prompted thousands of people to drive across state lines — sometimes multiple state lines — for an open vaccine appointment. Some states have set up residency requirements, although enforcement has been uneven and those seeking vaccines are often on the honor system.

Todd Jones, an assistant professor of economics at Mississippi State University near Starkville, said the confusion signals a need for a change in how the government handles the vaccine. “The Biden administration should definitely be thinking about how it might want to change state allocations based on demand,” Jones said. “If it does become clear that some states are actually not using lots of their doses, then I think it would make sense to take some appointments from these states to give to other states that have higher demand.”

Jagdish Khubchandani, a professor of public health at New Mexico State University, said no one should be surprised to see 50 different eligibility systems because states opposed a uniform federal eligibility system.

“Many governors don’t want to be seen as someone who listens to the federal government or the CDC for guidance,” he said. Florida Gov. Ron DeSantis, a Republican, has boasted of ignoring the CDC advice when he opted to make anyone 65 and older eligible beginning in December.

“There is a lot of political posturing in deciding eligibility,” Khubchandani said.

To be sure, governors also wanted the flexibility to respond to particular needs in their states, such as rushing vaccines to agricultural workers or those in large food-manufacturing plants.

Jones said the decision to open vaccines to all adults in the state may sound good, but Mississippi has one of the nation’s lowest vaccination rates. Part of that is attributed to hesitancy among some minority communities and conservatives. “It’s good news everybody can get it, but there doesn’t seem to be a whole lot of demand for it.”

Jones, 34, was able to go online for a shot on Tuesday and was vaccinated at a large church a short drive from his home on Thursday morning. “I was very happy,” he said.

– Phil Galewitz, KHN