(Mike Hutcmacher/Wichita Eagle via AP)

The ongoing measles outbreak that originated at Disneyland has infected dozens of people so far this year, with hundreds of additional people being monitored for exposure.

California has confirmed 79 cases as of Wednesday, a number public health officials expect will increase. In Arizona, more than 1,000 people — nearly 200 of whom are children — may have been exposed to the disease, according to the Arizona Department of Health Services.

“This is a critical point in this outbreak,” Will Humble, the director of the department, posted on his blog. He wrote that if potential cases are isolated, the outbreak could stop, adding: “However, if we miss any potential cases and some of them go to a congregate setting with numerous susceptible contacts, we could be in for a long and protracted outbreak.”

The outbreak has served as a reminder that quite a few people choose, for various reasons, not to vaccinate their children. While most people do get vaccinated for measles, the majority of those who get measles have not been vaccinated; many of the people with measles in California have not been vaccinated, the state’s health department said.

This has also sparked yet another round of debate over the vaccination issue entirely. Well, if you are wondering, most people tend to agree with the idea of vaccinating.

A new Pew Research Center study shows that while a majority of people — a really sizable majority of people, nearly seven in 10 people — say vaccinations should be required, there remains a considerable pocket of people who say parents should be able to opt out:

vaccines pew 1 - 1-29-2015

As the outbreak has continued, and authorities have warned of the danger faced by people who are exposed, the opposition to measles — which is highly contagious and which, in children, can lead to pneumonia and brain swelling — has also caused issues at schools and for families in California and beyond.

About 70 students at a high school near Palm Springs have been told to stay home from school because they have not been vaccinated, the Riverside County health department said Wednesday. The father of a 6-year-old boy in the Bay Area with leukemia asked the school district to similarly keep unvaccinated students out. Parents of a six-month-old girl had to keep her quarantined for 28 days after she was possibly exposed when an unvaccinated child went to her doctor’s office.

Meanwhile, here is the story of how we went from eliminating the disease in 2000 to an outbreak this year.