Some worry 'herd' safety is in jeopardy because of added risks
The herd in Oregon might be in danger.
Not buffalo, but school children, who share germs - and a risk of spreading contagious disease - in their classrooms on a daily basis.
Feb. 15 is the state's annual 'school exclusion day,' the day the Oregon Health Authority stops children who haven't received their state-required vaccinations from going to school until they meet the requirements.
The school vaccination law affects all of the state's 650,000 students in public and private schools, as well as Head Start programs and certified day care centers.
In Multnomah County, about 115,300 children must meet the requirements each year, with reminders sent to about 6 percent to get their paperwork in by the deadline. Fewer than 1 percent were actually excluded from school last year until they received the necessary vaccines.
'By far, most Oregonians immunize their children,' says Susan Wickstrom, spokeswoman for the Oregon Health Authority.
Most return to class within a couple of days, after receiving the vaccinations. Yet a growing number are allowed to attend school without being vaccinated, having been granted one of two types of exemptions: medical (undergoing cancer treatment, for example) or religious.
Religious exemptions are given to students whose parents or guardians check a box on a form stating that they don't believe in vaccinations or a specific vaccination.
The number of kindergartners with religious exemptions is on the rise statewide, up from 3.7 percent in 2006-07 to 5.6 in 2010-11. Rates in the Portland area vary along with demographics: Multnomah County's rate is 7.1 percent; Clackamas County 6.4 percent; Washington County 3.3 percent; Columbia County 3.8 percent.
In other pockets of the state, however, it's risen much higher, which health officials worry could endanger what's called 'herd immunity': the threshold that marks that population's resistance to the spread of disease, due to those who've been immunized.
As long as the population meets a certain threshold of people who've been vaccinated (80 percent for most diseases; 92 percent for pertussis, aka 'whooping cough'), the herd immunity will be strong, experts say.
For a disease such as rubella, with an 80 percent threshold, it would take five unvaccinated kids in a 25-student classroom for the herd immunity to break down, inviting the potential for spread of the disease to younger siblings and other medically vulnerable people who can't be vaccinated.
'We try to be at or above 95 percent for all the school-required vaccines,' a level that's set by federal government, says Stacy de Assis Matthews, school law coordinator for the state's public health division. 'When we start to fall below that rate, we start to get concerned.'
Regions with the highest rate of religious exemptions in the state are Jackson County at 7.7 percent; Lane County at 8.4 percent; Deschutes County at 9 percent; Wallowa County at 9.4 percent; and Josephine County at 12.1 percent.
This year, the state is requiring two new vaccines: Hepatitis A vaccine for second graders and the Tdap (pertussis booster) for ninth graders.
Science and safety
Most of the children with religious exemptions have received some vaccines, just not all, health officials say. They're trying to understand which vaccines parents are hesitant about, and address that.
'They should talk to their health care provider and get good science-based information,' says Wickstrom.
Part of the problem is that the diseases the immunizations are protecting against - such as diphtheria, polio and measles - aren't visible because they've been mostly eradicated. They could come back, however.
So what's behind the exemptions?
'I think religion is relatively broadly interpreted in Oregon,' says Dr. Paul Lewis, deputy health officer for Clackamas, Multnomah and Washington counties. 'It's not like you have to prove you're Catholic or anything.'
Lewis says his office has interviewed parents who opt out of one or more vaccinations to see what drives their decisions. He also hopes to break down data to see exactly which vaccines people are opting out of, and target information to help them make informed decisions.
Besides serving as the region's public health officer, Lewis is also a pediatrician and father of young children. He says he understands parents' lingering fears about about any link between autism and vaccines. Oregon has one of the highest autism rates in the country, but numerous studies have failed to find a link between the two.
'We try to use what we consider to be the most rigorous scientific claims to assess safety,' he says.
Lewis cites a four-part rationale to immunize a child: protecting that child against disease; protecting his or her loved ones, because seniors and infants are more vulnerable to disease and can't always be vaccinated; protecting the herd immunity; and protecting those in the community whose immune systems are fragile, such as cancer and HIV patients.
With increasing numbers of people opting out of immunizations, he says, the results won't be seen immediately, but will come over time.
He uses a forest fire analogy: 'It takes awhile for enough wood to build up for there to be a forest fire. If everybody stopped immunizing tomorrow, there wouldn't be disease, but as years go by the fuel ignites and an outbreak happens.'
A case in point: the huge measles outbreak in Europe between late 2009 and 2011. According to the federal Centers for Disease Control and Prevention, the 'primary reason for the increased transmission and outbreaks of measles in (the European region) is failure to vaccinate susceptible populations.'
Half the 26,000 cases of measles in one year hit children under 15.
Like forest fires, immunization rates had been down in the years prior to the outbreak: during 2004-10, the European region's coverage against the disease was at 92 percent to 94 percent; in France, it was 87 percent to 90 percent.
Pertussis is also a big concern: an outbreak in California two years ago killed 10 people, all infants younger than three months.
Jim Shames, county health officer for both Josephine County and Jackson County, agrees with Lewis that growing pockets of people have a distrust of medical science and therefore choose to opt out of some vaccinations.
The numbers in some schools in Ashland and Grants Pass are higher than in Multnomah County.
'There are subcultures, if you will, where people have concerns about the safety of vaccines so they create alternative schedule or withhold vaccines entirely,' Shames says. 'We seem to have more of those pockets here (in Southern Oregon).'
In Portland, the pockets are in charter, alternative and focus-option schools, which are part of the public school system but allowed to adopt many of their own rules and cultures.
A majority of Multnomah County schools have religious exemption rates of less than 10 percent at the kindergarten level, as they enter school. However many schools top the charts. At Portland Village School, a Waldorf methods public charter school in North Portland, nearly one in two students (47 percent) have a religious exemption from one or more vaccines.
One in three is exempt at Southwest Charter School and Opal Charter School. Southwest Charter describes itself as 'a K-8 school which offers a different educational experience, encouraging exploration of the natural world and involvement in the local community through the arts and sciences.'
Opal, based at the Portland Children's Museum, is a K-5 school 'provoking fresh thinking about learning environments that inspire playful inquiry, creativity, imagination and the wonder of learning in children and adults.'
Other rates are nearly as high: 32 percent at the alternative Metropolitan Learning Center (in the grades K-6 program); 31 percent at North Portland's Trillium Charter School; 26 percent at Southeast Portland's Sunnyside Environmental School's elementary program; 24 percent at Southeast Portland's Creative Science School; and 23 percent at Emerson School, a Northwest Portland K-5 charter.
School nurses, office managers and others who picked up a Tribune reporter's phone call at each of those schools this week declined to answer any questions or discuss some of the reasons parents opt out of vaccines.
Shames says it's a matter of simple math: 'You know what percentage of kids have to be immunized to prevent an outbreak, and if you're below that number … it's kind of frightening,' he says. '(An outbreak) probably is a matter of time. The disease isn't going to go away.'
Lewis recognizes that it's a complex problem with no simple solution. Like religion, and school choice, people's health care decisions are deeply tied to their belief systems.
'Portland is a land of many opinions,' he says. 'We can't force people to get immunized, we can only persuade them.'