Many medical professionals say it's important for people, especially children, to get immunizations.

"I think a lot of times now a lot of people haven't seen the diseases, so we forget why we're immunizing and what happened to children when they got polio or when they got haemophilus meningitis," said Bozeman Deaconess Pediatrician Angie Ostrowski.

But there are some people who worry vaccines could have negative effects on their children.

"That doesn't mean that it's not ok to be worried about it, and I think that that's the thing that parents need to hear is of course you're concerned, you don't want to do anything that might harm or change your child, let's talk about the studies that have been done, what we know is true and make some decisions from there," said Ostrowksi.

Health department officials say this November's whooping cough outbreak at Bozeman High School may have been smaller if every student was vaccinated.

"When we had our pertussis outbreak in November in the high school we definitely saw more severe symptoms of pertussis in those kids who were not vaccinated then those kids who had been vaccinated," said Jill Steeley, Director of Human Services form the Gallatin City-County Health Department.

Montana is typically one of the lowest ranked states in immunization for children in the U.S. but the newest numbers have Montana moving up to 31st from 47th.

"We're doing our job getting out there, educating the public a little bit more about vaccinations and the importance of getting your kids vaccinated, getting yourselves vaccinated," said Steeley.

Ostrowski says diseases like polio have been almost completely eliminated in the U.S. due to vaccines, but the less people vaccinate, the more likely those diseases are to come back.

"We're not seeing them because we've been vaccinating against them and vaccination rates looking high is really important to those diseases staying away," she said.

Since January 1st, 376 pertussis cases have been verified in Montana, the most since 2005. Medical officials say that's a sign that as our immunization rates drop, occurrence of the diseases goes up.