MINNEAPOLIS (WCCO) – The outbreak of measles has generated lots of debate about vaccinations over the past month. Even politicians have weighed in on whether they should be mandatory.

But, opinions aside, can we actually force people to get immunized? Good Question.

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“Yes,” said University of Minnesota law professor June Carbone. “There’s no question of the ability to order it. The question is what exceptions might people argue for.”

While some federal legislation does exist, much of the law comes at the state level.

Mandatory vaccination laws have been on the books since the smallpox outbreaks of the early 19th century. It wasn’t until the measles outbreaks of the 1960s and ’70s that every state has required vaccinations before kindergarten.

Each state has its own exemptions. In Minnesota, state law allows for medical, religious and philosophical objections. Mississippi and West Virginia are at the other end of the spectrum, and only allow exemptions for medical reasons and only when “such exemption will not cause undue risk to the community.” Children who don’t comply can be suspended.

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When it comes to private businesses, the states’ exemptions don’t apply because states generally don’t want to legislate what employers can do. But employers cannot discriminate based on religious reasons.

“The question is, ‘Do you have to allow exceptions for people whose religious beliefs forbid it?’ and the answer we get from the courts is, ‘Mostly no,’ but sometimes they say, ‘Yes,’” Carbone said.

Using hypothetical examples, Carbone said a restaurant in the middle of flu epidemic requiring its employees to vaccinate would likely be allowed, but a company issuing blanket vaccination for all of employees without an religious exemption would likely be challenged.

For years, the definitions of religious exemptions have been litigated. At the same time, Carbone said states are offering more leeway when it comes to religious and philosophical beliefs.

In many cases, healthcare workers are held to a different standards. Some states require them to be vaccinated with different opt-outs, including medical, religious and philosophical exemptions.

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In 2009, the state of New York mandated healthcare workers be vaccinated against influenza, with exceptions for medical contraindications. Later that year, the courts and the governor suspended the law. In 2013, healthcare workers who were not immunized in New York were required to wear masks when influenza was present.