While much of the attention in the ongoing measles outbreak has focused on student vaccination requirements and exemptions, less attention has been paid to another group in the nation's classrooms: Teachers and staff members, who, by and large, are not required to be vaccinated.
In most states, there is no law dictating which vaccines teachers and school staff workers are required to get. Some states provide a list of recommended vaccines, but there is no requirement or follow-up for teachers to receive them.
So when a measles case surfaced at a California high school, it was easy for officials to review student records, but there were no immunization records on file for employees.
That meant all 24 teachers and staff exposed to the employee with measles had to prove their immunity -- records that, for most, were decades old.
The issue has surfaced from time to time in state legislatures and is likely to be raised again in response to the latest outbreak, which originated at Disneyland in December and has spread to a half dozen states and Mexico. Most of those who fell ill were not vaccinated. As of Friday, public health officials said 114 people had contracted measles.
"I was definitely shocked," Rep. Joanna Cole, a Democrat in the Vermont Legislature, said when she learned in 2012 that there were no teacher vaccination requirements in her state. There are still no requirements today. "I guess we all just assumed that they would have them."
Cole and other legislators and parents across the U.S. believe the blanket presumption that teachers are up to date on their vaccines should be re-examined. They note that most of those sickened in the current outbreak are adults, and that schools are one of the top places for the spread of communicable disease.
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"I will be surprised if we don't see some changes in the next year to year and a half," said Kristen Amundson, executive director of the National Association of School Boards of Education.
Already, some states are considering measles legislation. In Vermont, Democratic Rep. George Till says legislators will try this year to eliminate philosophical exemptions for students and require that teachers be up to date on the same vaccines students must receive.
"If we're trying to limit the spread in school, why just students?" Till said. A similar bill he introduced in 2012 was defeated amid strong opposition from anti-vaccine groups, and he expects another battle.
In Colorado, pro-vaccination groups have been pushing the Department of Human Services to require vaccinations for workers at child care facilities, another area with uneven employee immunization standards. Measles cases have been confirmed at day care facilities in Chicago and Santa Monica, California.
Barbara Loe Fisher, director of the National Vaccine Information Center, a Virginia-based nonprofit that favors letting parents decide whether to vaccinate, said the discussion on vaccination requirements has started to expand from schoolchildren to certain adult professions. She said her organization has a number of concerns about requiring teacher vaccinations, including safety and job protection for those who cannot or choose not to be immunized.
"I think at the end of the day, the most important principle to protect is the right to make an informed voluntary decision, and that includes teachers," she said.
At Vista Murrieta High School in California's Riverside County, a middle class community between Los Angeles and San Diego, all teachers and staff who had been exposed to the measles were able to return to work within one to three days. Teachers who were born before 1957 were immediately excused, assuming they had either had gotten measles as a child or been exposed to the disease.
Kathy Ericson, president of the Murrieta Teachers Association, said the instructors were willing to do "whatever needs to be done" to protect students. But she stopped short of saying whether vaccination or proof of immunization should be required for employment.
"Most of us don't have our shot records," she said. "It would be a hard thing to go back and prove."
Several parents with students in Murrieta Valley schools said they believed it was important for teachers to show proof of immunity or get vaccinated to protect their children and others too young or vulnerable to get the vaccines themselves.
"It is everyone's responsibility to keep students healthy and safe," said Sherrie Zettlemoyer, the mother of two elementary-school students. "I believe if you can be vaccinated you should."