Much of the attention in the measles outbreak has focused on student vaccination requirements, but less attention has been paid to another group in the nation's classrooms: teachers and staff members, who in general 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.

So when a measles case surfaced at a California 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 is likely to be raised 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.

Legislators and parents across the U.S. 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.

"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 require that teachers be up to date on the same vaccines students must receive. 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 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.