It began in December at "the happiest place on earth": a measles
outbreak that spread across the West, infecting more than 150 people.
The eruption at Disneyland
occurred 14 years after health officials had declared the potentially
deadly disease eliminated from the United States, thanks in part to
childhood vaccination programs. The outbreak raised alarm that more
scares could be on the way.
California lawmakers quickly moved to tamp down a growing resistance to vaccination that had been fostered in some communities by unfounded safety concerns. By summer, Gov. Jerry Brown had signed one of the nation's toughest laws to keep parents from opting not to inoculate their kids.
Nationwide data released Thursday by the U.S. Centers for Disease Control and Prevention
show that although California children are immunized at a high level,
the state's vaccination rate still lags behind the rest of the country.
The nationwide median vaccination coverage for kindergartners for
measles, mumps and rubella as well as for diphtheria, tetanus and
acellular pertussis, or whooping cough, was about 94% for the 2014-2015
school year. And exemption rates remained very low, with a median of
1.7%, the report shows.
"Overall, the news is gratifying," said Dr. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases.
"Though they may not always get the headlines, the overwhelming
majority of parents continue to protect their children with recommended
vaccinations."
The national rates were calculated using data from 4 million children entering kindergarten in 2014.
In California, the picture was less rosy, though experts said that
could soon change as the new state vaccine law goes into effect.
For
California kindergartners entering school in fall 2014, the
immunization rate for measles, mumps and rubella was 92.6%, and for
diphtheria, tetanus and acellular pertussis was 92.4%, the CDC found.
"There's
still work to be done to raise vaccination rates in communities or
local pockets where children aren't fully vaccinated," Schuchat said.
"When a virus like measles reaches a group of unvaccinated people,
trouble can follow."
Vaccination
rates among California kindergartners declined between 2001 and 2013,
particularly in affluent and coastal areas of the state. The decline was
caused in part by an increase in waivers that allowed parents to refuse
to vaccinate their kids. Public health officials said that exacerbated
the measles outbreak.
Thursday's report found that the percentage of kids in California who
claimed exemption in the 2014-15 school year was 2.7%. Though that's
still higher than the national rate, it's a drop from the previous year's rate of 3.3% — a trend that health officials say they hope will continue.
California
kindergartners are currently required to get vaccines, but can get
medical or "personal belief" exemptions. The new state law, starting in
2016, bans philosophical and religious exemptions, making California the
third state in the country to allow only medical exemptions.
Parents can still decline to vaccinate children who attend private home-based schools or perform independent studies off campus.
Two
other states that also ban belief exemptions, West Virginia and
Mississippi, have the lowest opt-out rates in the country at 0.2% and
less than 0.1%, respectively, according to the CDC data. Together, the
two states had 55 kids citing an exemption.
California's passage of the ban was controversial, drawing hundreds of protesters in Sacramento.
Brown, however, said he believes the science about vaccines is clear.
"While
it's true that no medical intervention is without risk, the evidence
shows that immunization powerfully benefits and protects the community,"
he said in a statement after signing the bill in June.
For several years until 2006, about 95% of California's kindergartners were fully vaccinated for measles.
The
drop to 92.6% concerns health experts. Lower immunization rates, they
say, can lead to a loss of "herd immunity," a situation in which the
immunity of a crucial percentage of people drastically reduces the
chances of a disease spreading. Experts say that conditions for an
outbreak worsen when 8% or more of the population is not immunized.
The
national data found that in the 2014-2015 school year, 32 states had
vaccination rates for measles, mumps and rubella under 95%, and seven
had rates under 90%.