Measles has now spread to 14 states and there are no signs of its slowing, with the latest figures from the Centers for Disease Control and Prevention showing 102 people are infected.

In response, government officials are urging parents to vaccinate their children. Dr. Tom Frieden, director of the CDC, said Sunday on CBS’ “Face the Nation” that the U.S. could see a large outbreak and reminded parents that the disease is preventable through vaccination. Overall, the U.S. has a 92 percent vaccination rate, he said.

During an interview on NBC’s “Today” show, President Barack Obama said the science about vaccines is indisputable, and also urged parents to get their children vaccinated.

"We've looked at this again and again. There is every reason to get vaccinated, but there aren't reasons to not," he said.

New Jersey Gov. Chris Christie on Monday called for a more balanced approach to the issue, saying parents should have "some measure of choice" when it comes to vaccinating their children.

A potential Republican presidential candidate, Christie said he and his wife had their children vaccinated. Later, his office clarified his statements, saying that there is no question children should be vaccinated.

"The governor believes vaccines are an important public health protection and with a disease like measles there is no question kids should be vaccinated," his office said in a statement. "At the same time different states require different degrees of vaccination, which is why he was calling for balance in which ones government should mandate."

The majority of people who caught the virus this year were not given the MMR vaccine for measles, mumps and rubella, which typically is administered around the age of 1 and again before a child enters kindergarten. The first vaccine has a 95 percent effectiveness rate, and the second has a 99 percent effectiveness rate. At least five of those infected in the current measles outbreak had received both vaccines.

Though schools have immunization requirements for students, most states provide exemptions for religious objections and some allow philosophical exemptions. Neither Frieden nor Obama specifically addressed whether states should be more strict with their vaccination policies, though Frieden, when prompted, replied that such a decision is one for school boards and communities to make.

“If we increase those vaccination rates, we can stop measles just as we have before,” he said.

Before the creation of a vaccine in 1963, 500 people died of measles each year, and 4 million caught the virus. There have been no deaths in the U.S. from measles this year, but officials are concerned because the disease was considered to be largely eliminated in the U.S. in 2000. “We have to stop it from getting a foothold here,” Frieden said Sunday.

Obama had the same message: “We should be able to get back to the point where measles effectively is not existing in this country,” he said.

The majority of infections during this outbreak have been linked to the Disneyland theme park complex in Anaheim, California. The virus is highly contagious and spreads through contact with infected persons and surfaces, and through the air. In Arizona, where the Super Bowl took place Sunday, health officials were monitoring about 1,000 people who could have been infected. Those who were not vaccinated were asked to stay home for 21 days.

Measles is a virus that begins with a high fever and leads to a runny nose, cough, and red and watery eyes. After a few days, a rash develops and spreads all over the body. People who recover from measles are immune for the rest of their lives, though unlike the flu, there is no specific antiviral treatment for the illness. Care instead is supportive, and includes a focus on hydration and nutrition. Antibiotics can be prescribed in cases where pneumonia or an ear or eye infection develops.

A person with measles is contagious for four days before and after a rash appears, meaning someone may have the virus and not know it. The CDC has not yet identified the person who initially spread the virus at Disneyland.

This outbreak follows an already brutal year for the virus, with 2014 seeing the highest number of cases since 2000. According to the CDC, 27 states reported 644 cases last year, the majority of which were among people who were not vaccinated. Public health officials attributed the spread to people traveling from the Philippines, which experienced a measles epidemic.

Though a fear of vaccines has contributed to the measles outbreak, a U.S. News analysis found that other factors also likely contributed. The majority – 63 percent – of cases in California have occurred in people over the age of 20, meaning that some of those infected were not part of public health initiatives during the early 1990s that aimed to vaccinate children.

Some families also delay vaccinations rather than refuse them outright, and some are unable to see a doctor regularly.

“Even among those parents whose kids have not been vaccinated, most of them don’t have that deeply held concern – they just might not recognize that measles is still with us, that it’s serious, and that not getting your kid vaccinated is not only a risk for your own kid, but puts other vulnerable kids in your community at risk,” Frieden said during his CBS interview.