While data indicate exceptionally high immunization coverage at regional level, they also reflect a record number affected and killed by the disease.
Experts can't say for sure where the next outbreak might be.
Measles is a potentially deadly infection that is most common for small children.
And leading health officials are stressing the importance of getting vaccinated.
Europe had a record number of measles cases a year ago, in part due to a growing number of pockets where parents are refusing to vaccinate their children, the World Health Organisation (WHO) says.
The "anti-vaxxers" movement still thrives in many pockets of the United States.
More than 82,000 people in the European region - an area stretching from Russian Federation to Iceland and south to Malta - caught measles in 2018, the most infections in the past decade, the agency said in an emailed statement.
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CDC says pregnant women should get vaccines for the flu and whooping cough.
Heidi Larson, a specialist in vaccines and public health at the London School of Hygiene and Tropical Medicine, said the increase in cases was a "wake-up call on the importance of building confidence in vaccination".
Adult vaccination numbers in the county also rose. "Our one doctor here, who has been [a] practicing physician for 12 years, had never seen a case of measles until a month ago". Most importantly, at least 95% of every population needs to be immune, through two doses of vaccination or prior exposure to the virus, to ensure community protection for everyone - including babies too young to be vaccinated and others who can not be immunized due to existing diseases and medical conditions.
But it's a snapshot of the scare an outbreak can cause, said Dr. Alan Melnick, the Clark County health officer overseeing the response.
Wednesday, February 6, three of the four possible cases have been ruled out as measles.
The Department of Health (DOH) declared a measles outbreak in Metro Manila with a spike in measles in cases, while placing several regions under tight watch. Only 81% of 1 to 5 year olds in the county have received a dose of MMR, according to Clark County, Washington Public Health. However, it can not make us blind to the people and places that are still being missed.
The World Health Organization (WHO) reports that in order to reach the measles herd immunity threshold and stop the spread, at least 93-95% of the population must be up-to-date on vaccinations.
The only reason - let us stress, the only reason - why our kids are at risk for measles today is that a segment of the population is choosing not to vaccinate their kids.