Measles is spreading quickly in California, with 50 confirmed cases and outbreaks mapped in five regions since the beginning of 2019, according to the California Department of Public Health.
Meanwhile, one-third of schools serving kindergartners or seventh graders in San Luis Obispo County do not have vaccination rates high enough to achieve community immunity against the preventable disease, according to a Tribune analysis of 2018-2019 state data.
Does that matter if your kid is fully vaccinated? The short answer is “yes.”
Low vaccination rates put the community at greater risk for the disease to spread quickly, public health officials say, increasing the likelihood of infection for those who aren’t vaccinated, those who can’t be vaccinated because of weakened immune systems or allergies and even those who are up to date on all their vaccines.
A healthy, vaccinated child in a classroom with children who are not vaccinated has a far lower risk of than a child who is not vaccinated. They’re less likely to contract measles and if they do, it will be less severe.
However, not all vaccines are 100% effective 100% of the time, according to the San Luis Obispo County Health Department. It’s also possible that a vaccine may have been administered improperly or not stored at the right temperature, although that is rate..
Half of the adults who contracted measles in California in 2019 had received one or more doses of the measles vaccine, according to the California Department of Public Health. All of the children diagnosed with measles were unvaccinated.
National public health officials point to high vaccination rates as the reason why the deadly disease was considered eliminated from the United States in 2000.
As vaccination rates declined, the measles spread. More than 1,100 cases have been confirmed in the United States in 2019 so far, the highest number in a quarter century.
While several people may recall the measles as simply part of childhood, the disease is highly contagious, preventable and sometimes deadly.
Each year in the decade before the 1963 development of the vaccine, about 400 to 500 people died, 48,000 were hospitalized and 1,000 suffered swelling of the brain that can lead to convulsions, deafness or intellectual disability, according to the U.S. Centers for Disease Control.
These days, death by measles is rare in the United States. The last known U.S. death from measles was in 2015.
Local schools with low vaccination rates
In San Luis Obispo County, 20 schools serving kindergartners and five schools serving seventh graders had vaccination rates below 95 percent — the rate at which research has shown offers community or “herd immunity,” the most recent data show.
A vast majority of those are private schools, some of which reflected a high rate of children with doctor’s notes that exempted them from receiving one or more required vaccines.
Public health officials say the risk of harboring an outbreak is greatly reduced as the vaccination rate reaches 95 percent. That means that schools with a rate of 93 or 94 percent aren’t really that much of a concern.
But several schools in San Luis Obispo County have documented rates lower than 90 percent.
The schools with the lowest rate of fully immunized children are San Luis Obispo Classical Academy, where 85 percent of seventh graders had all their vaccines, and Old Mission School in San Luis Obispo, where 80 percent of kindergartners and 92 percent of seventh graders were fully immunized.
Measles spreads with travel, SLO County has been spared
So far, San Luis Obispo County has been spared.
No cases have been reported in 2019. And, unlike the trend seen nationwide, the county did not experience an increase in preventable diseases when the vaccination rate was relatively low, from about 2005 to 2015.
Rick Rosen, county deputy public health officer, says that might be because of the county’s proximity to nearby populations.
“We live in an area with a relatively small population that is relatively isolated That offers some protective advantage in terms of disease outbreaks,” Rosen said. “If you have low vaccination rates and the disease is in your relatively small population, it’s a recipe for problems.”
Isolation matters because measles usually makes its entrance into a community through importation after someone has traveled.
The first person diagnosed with measles in Santa Barbara in 2019 was a man in his 20s, who in May spent most of the contagious period traveling, leading public health investigators to check with his contacts across the state to see if anyone he contacted had symptoms.
The latest measles outbreak was reported in April in Los Angeles County, where public officials said exposures may have occurred at an airport, library, university and several restaurants.
In general, health officials point to international travel as a source of domestic outbreaks. Cases in Europe — Poland, Israel, France and the Ukraine, in particular — seem to be linked to some in the United States.
In the first four months of 2019, more than 43,000 cases of measles and 15 deaths were reported in the Ukraine.
Correction Aug. 14: This article was edited to correct the spelling of an official’s name.