Childhood immunization seems like a no-brainer: Protect kids from serious diseases by vaccinating them at a young age. Unfortunately it’s not as simple as it sounds. Nationwide, 77 percent of children have received routine vaccines, according to the Centers for Disease Control and Prevention -- far below the 90 percent goal set by the Association of State and Territorial Health Officials.

A variety of factors contribute to this less than ideal immunization rate for children, but one in particular stands out: A number of states have made it easy for parents to exempt a child from receiving a vaccination for personal or religious beliefs. In California, for example, parents simply sign a prewritten statement on their children’s school immunization form. It’s actually easier to claim an exemption than it is to complete the immunization form, according to a study by the Journal of the American Medical Association.

States that have the easiest exemption rules have seen 90 percent more cases of pertussis, better known as whooping cough, than other states, according to the Journal’s study. In California, the outbreak is the largest the state has seen in almost 55 years, with more than 6,600 reported cases and nine infant deaths. But another state, Colorado -- which has a similar exemption rule -- has seen only 220 cases as of Oct. 31.

“We’ve seen an increase in cases in the last two months, but we’ve not seen the dramatic increase that they’ve seen in California,” says Joni Reynolds, director of Colorado’s Immunization Program at the Department of Public Health and Environment. “In an average year, we have 232 cases, so we may be on track for an above average year -- but we’re not at a startling level.”

Why has each state had a drastically different number of whooping cough cases this year, despite the fact that they share this exemption policy? While the number of pertussis cases are a fraction of a percent of each state’s population, the increase from 2009 to 2010 -- more than 400 percent in California compared to less than a 25 percent increase in Colorado -- signifies that perhaps there are differences in the way the states handle vaccines and outreach.

In 2009, Colorado created the Circle of Protection Program, which provides free tetanus, diphtheria and pertussis vaccines to hospitals so they can vaccinate health-care workers, other adults working with infants and new moms before they’re discharged, and give coupons to fathers and close family members for free vaccinations at local health departments, creating a “circle” of vaccinated adults around unprotected infants and children.

In January, Colorado will launch a new outreach effort that targets parents who already vaccinate their children. The Immunize for Good campaign will seek to empower, support, educate and provide resources that are parent-directed, according to Reynolds who adds that 80 percent of children in the state are immunized by age 2. “As health-care professionals -- I’m a nurse -- we know the science behind vaccines, but we need to have that information translated into what parents need.” The immunization campaign also will have a website,, with interactive features like blogging and question boards, as well as animated sections that illustrate how different diseases affect the body.

“There are so many things for parents to worry about today that vaccines and immunizations may get sort of diluted,” Reynolds says. “So the website brings those things forward and gives parents a place to go to get information.”

As Colorado is proving, a state can maintain a fairly lax vaccination exemption policy and still keep diseases like pertussis in check through outreach and prevention.