With an outbreak of measles continuing to spread, the question of whether parents should be allowed to choose not to immunize their children has become a hot topic.
California requires students in both public and private schools to be immunized, but exempts children from immunization requirements for two reasons: medical and "personal belief."
San Mateo County has lower rates of personal-belief exemptions than many other counties, at 1.85 percent. Marin County is at 6.45 percent, Tuolumne is at 7.36 percent, and the overall state rate is 2.54 percent.
Parents at some local schools, however, have opted out of immunizations for their children at rates high enough that medical experts say they could put at risk those who can't be immunized, including those too young to be fully immunized and those with suppressed immune systems, such as cancer patients.
Menlo Park's Peninsula School, according to statistics from the California Department of Public Health, has the highest reported percentage of personal-belief exemptions in San Mateo County this school year: 30 percent of this year's 30 kindergartners (nine students).
The opt-out rate at Peninsula has been even higher in the past. State statistics show that the school had a 46 percent personal-belief exemption rate for children in its 2010-2011 kindergarten class.
Las Lomitas School in Atherton has the highest public school opt-out rate in the local area. Natalie Siemers, a Las Lomitas District nurse, says the school currently has 137 kindergartners, with eight students opted out with personal-belief exemptions and two others with permanent medical exemptions, for a 93 percent vaccination rate.
Other local schools with high personal-belief opt-out rates for 2014-2015 kindergarten classes, reported by the California Department of Public Health, are:
● Laurel School, Atherton, 5 percent.
● Philips Brooks, Menlo Park, 5 percent.
● Encinal School, Atherton, 4 percent.
The reason the number of children who are not immunized matters, medical experts say, is because high immunization rates offer "herd immunity," protecting those who can't be immunized.
Dr. Scott Morrow, San Mateo County's health officer, says that the rate of immunizations required to confer herd immunity varies depending on how contagious a disease is. Measles, he said, is so contagious that a 99 to 100 percent immunization rate is required to protect the non-immunized.
"It's so likely to be transmitted if you're exposed and non-immune," he said.
Other doctors say 90 percent of those who are non-immune and exposed to measles will catch it.
The state requires five immunizations: DPT (diphtheria, pertussis, tetanus), polio, MMR (measles, mumps, rubella) hepatitis B, and varicella (chicken pox). Most children who are opting out of the MMR vaccine appear to not be receiving any of the immunizations.
According to the state's data from November, Peninsula School reported that nine out of 30 kindergartners at the school did not have four of the vaccinations, with 10 students not immunized for hepatitis B.
At Las Lomitas School, which has two kindergartners with permanent medical exemptions, the school reported in November that 10 out of 137 kids do not have four of the vaccinations, with 12 not immunized for hepatitis B.
Kit Sanderson was one of those who depended on herd immunity for her health as a young student. Just before she entered kindergarten at Woodside Elementary School in 2003, Kit was diagnosed with leukemia.
Her mom, Dana Sanderson, says because Kit's cancer treatment had suppressed her immune system, she was in danger from any communicable disease, especially chicken pox. The school reminded all the other kindergarten parents to immunize their children to help protect Kit.
One parent told her, Dana Sanderson says, that while her family had previously made a decision not to vaccinate their child against chicken pox, they had changed their mind when they saw that not doing so could endanger a classmate.
Kit Sanderson, whose family now lives in South San Francisco, is now in high school and is considered a leukemia survivor, her mom says. She is also fully immunized.
In addition to those with compromised immune systems, children too young to be fully immunized are also at risk. The first dose of a measles, mumps and rubella immunization, known as MMR, is at 12 months but children are not considered fully immune until they receive a second dose at age 4 to 6. Many adults received only one dose of MMR vaccine and many medical experts now recommend that anyone 18 or older who was born after 1956, and who has not had the measles, receive a booster shot.
Part of the reason measles is so contagious is that it is spread through the air. Measles, according to Dr. Scott Smith, chief of infectious disease and geographic medicine at Kaiser Permanente Redwood City, "is classified as, if not the most infectious, as one of the most infectious" diseases. It can persist, hanging in the air if you will, even after a patient has left a room or a closed space," he said. Even in Kaiser's specially ventilated isolation rooms, once a measles patient leaves, no one is allowed to enter for two hours, he said.
Because measles is so contagious, the county's policy, which local public and private schools confirm they follow, is to send any non-immunized children home for three weeks when there is a case of measles in their school.
Doctors are required to report all measles cases to the county health department. When a case is reported, San Mateo County's Dr. Morrow said, "we identify all the contacts and usually there are many, if not hundreds." Each contact's immunization records must then be checked and if they have not been immunized, or do not have antibodies showing they have had measles, they must be isolated at home for three weeks.
Last week, on Feb. 4, two California state senators introduced legislation that would eliminate the personal-belief exemption. One of the authors, Dr. Richard Pan, a pediatrician and senator representing Sacramento, said he has "personally witnessed the suffering caused by these preventable diseases."
U.S. senators Barbara Boxer and Dianne Feinstein also want personal-belief exemptions, including those for religious beliefs, eliminated. "While a small number of children cannot be vaccinated due to an underlying medical condition, we believe there should be no such thing as a philosophical or personal belief exemption, since everyone uses public spaces," the senators wrote in a letter to state officials. "As we have learned in the past month, parents who refuse to vaccinate their children not only put their own family at risk, but they also endanger other families who choose to vaccinate."
They also noted that current state law allows "two options for parents to opt out of vaccine requirements for school and daycare: they must either make this decision with the aid of a health professional, or they can simply check a box claiming that they have religious objections to medical care. We think both options are flawed, and oppose even the notion of a medical professional assisting to waive a vaccine requirement unless there is a medical reason, such as an immune deficiency."
Dr. Pan also wrote legislation that took effect in January 2014 requiring parents who want a personal-belief exemption to first talk with a licensed health care practitioner about the impacts to their child and community. This year, for the first time in many years, the rates of personal-belief exemptions went down statewide.
Part of the reason for the decrease, according to Dr. Eric Weiss of the Village Doctor in Woodside, may be because parents who have a chance to talk to a trusted doctor will usually choose to vaccinate their children. At the Village Doctor, which is a concierge medical practice where doctors have few patients and more time than other practices to spend with them, not one family has chosen not to immunize their children, he said.
Having the luxury of spending time with a trusted doctor allows families "to come to a more informed choice about risk and benefit," he said. "If you have a half hour to talk about it, I believe the informed decision is yes."
Measles is not the only disease that has reappeared in recent years. Last year 133 cases of pertussis, or whooping cough, were reported in San Mateo County. Statewide, the California Department of Public Health says there were 10,831 reported cases of whooping cough last year, with 376 people hospitalized and 60 percent of those hospitalized younger than 4 months old. Two infants, both younger than 5 weeks old when they caught the disease, died from whooping cough last year.
Dr. Weiss said part of the reason that more and more parents have chosen not to vaccinate their children may be because the diseases being vaccinated against have become so rare that parents cannot imagine their dangers.
"We all know families who are struggling with an autistic child, and we don't know families whose children are paralyzed from polio or dead from a pneumococcal disease or deaf from a pneumococcal infection, (which) were all common problems" at one time, he said.
Kaiser's Dr. Smith said an experience he had about 10 years ago reminded him of the rarity of diseases now immunized against, and their danger to the non-immunized. A patient from Woodside had traveled to a foreign country for work. "He came back with a mysterious illness," Dr. Smith said. "I couldn't figure it out."
That is, he said, until a week later when the man's 12-month-old daughter was brought in to Kaiser with a high fever and a rash. One glance from an older pediatrician confirmed that the daughter, and her father, both had measles, Dr. Smith says.
Coincidentally, the family had just received a reminder phone call to bring the child in for her first MMR vaccination. Other children who were in daycare with the child also got the measles, he said.
"That whole case illustrates a variety of things," Dr. Smith said. "It happens every once in a while" that a disease like measles appears and, he said, can easily spread to those who aren't immunized.
Curious about your school?
Overall immunization rates reported for local schools' current kindergarten classes, according to the State Department of Public Health, range from 67 percent at Peninsula School in Menlo Park to 100 percent at both Woodland School in Portola Valley and Willow Oaks School in Menlo Park.
Click here to see school information, which was due to the state by Nov. 21, 2014. School officials note that the percentages may not be up to date because they include students with incomplete paperwork as not immunized.
Click here to see a KQED website, which has taken the state data for the past seven years and used it to make bar graphs showing each school's percentage of personal-belief exemptions. Use the search box to find the school or city you are interested in.