The ongoing measles outbreak in California now stands at 92 cases.
The spread of the highly infectious disease has sparked a debate about people who voluntarily opt out of vaccines or decline to have their children vaccinated.
Many people have no choice. They can't be vaccinated for medical reasons. They rely on the people around them to be vaccinated to prevent the spread of infectious disease.
The Krawitt family in Marin County, Calif., is taking action to try to increase rates of vaccination in their community because 6-year-old Rhett can't be vaccinated.
"I got leukemia when I was 2," Rhett says. "It's a cancer of the blood, and you can die from it."
After three years of chemotherapy, Rhett is in remission. Now there's a new threat: measles. In California, people can legally refuse vaccines for themselves and their children. Marin County has a high rate of these so-called personal belief exemptions. And that worries Rhett's father Carl.
As we first reported on Jan. 26, Carl is pleading with other parents: Please vaccinate your children, because people with compromised immune systems, including his son, can't be vaccinated.
In the past week, Carl Krawitt's efforts have gained national attention, part of a growing debate on the ethics and health consequences of parents refusing to vaccinate.
But public health officials and school districts have to navigate a thorny issue: How do you respect people's personal medical choices with keeping the population safe from preventable disease?
Marin County health officer Dr. Matt Willis says he is "extremely sympathetic" to the Krawitts' situation, but science does not back up their request to keep kids out of school.
"There's little evidence that excluding unvaccinated children from a school where there's no evidence of measles transmission would be an effective public health strategy for limiting the spread of disease," Willis said.
In addition, if he were to exclude unvaccinated children from school, that would mean Rhett and others with a medical exemption from vaccines would have to stay home, too.
"Picking only one child who is allowed to attend school and excluding the others would be inconsistent."
Meanwhile, the Krawitts' school district has been working aggressively this school year to get children who are behind on their vaccines caught up.
Lisa Aliferis, editor of KQED's State of Health blog, broke the story about the Krawitt family's efforts to increase vaccination rates in their community in the midst of a measles outbreak. She continues to report the story as part of a partnership with NPR, KQED and Kaiser Health News.