"Progress has been uneven between and within countries, leaving increasing clusters of susceptible individuals unprotected, and resulting in a record number of people affected by the virus in 2018," it said.
It's not only Europe that has been impacted by a spike in measles cases.
Madagascar, the island nation off the coast of East Africa, has experienced its worst measles outbreak in decades.
The secretary general of the ministry of health told CNN that more than 50,000 people have caught the disease since October 2018 and there have been more than 300 deaths - mostly children.
In the Philippines, there have been more than 1,800 measles cases and 26 deaths so far this year, according to the country’s Department of Health Epidemiology Bureau.
This represents a 74 per cent increase from 2018.
Measles outbreaks have also sprung up in in more than a dozen US states since the start of 2019.
According to the Washington Post, at least 55 people in Washington and neighboring Oregon have gotten sick with the virus, with new cases tallied almost daily.
Measles alert in Australia
In NSW there have been 11 cases of Measles since Christmas.
A man and a baby became ill upon returning home on a flight to Sydney from the Philippines in January.
Source: AAP Image/EPA/FRANCIS R. MALASIG
The case prompted NSW Health to urge people travelling to South East Asia to ensure they are fully vaccinated before heading overseas.
"Outbreaks of measles in popular tourist destinations mean the risk for measles being imported into Australia at the moment is high," said Dr Vicky Sheppeard, Director Communicable Diseases NSW Health.
What is Measles?
Measles is a highly contagious viral disease that can cause hearing loss and brain disorders in children and, in severe cases, can kill.
Symptoms of measles include fever, sore eyes and a cough, followed three or four days later by a red, blotchy rash spreading from the head and neck to the rest of the body.
Experts agree vaccination coverage needs to be around 95 per cent to prevent the virus circulating in communities - so-called "herd immunity".
Rise in infections blamed on immunisation 'gaps'
Gaps in vaccination coverage, complacency about the disease and a resistance by some parents to have their children immunised has been blamed for the concerning rise in infections.
In many countries, anti-vaccine campaigners seek to dissuade parents from getting their children immunized, despite strong scientific evidence that vaccines are safe and effective.
In Italy, the co-ruling anti-establishment Five Star Movement has questioned the safety of some vaccines and loudly denounced efforts to make vaccinations mandatory.
WHO European director, Zsuzsanna Jakab
(Immunization) gaps at local level still offer an open door to the virus
In the WHO’s European region, which covers nearly 900 million people, some 82,600 in 47 countries contracted measles last year - the highest number this decade. Of those, 72 cases were fatal.
In 34 of these countries, estimated coverage with a second dose of measles vaccine was below 95 perc ent.
"(Immunisation) gaps at local level still offer an open door to the virus," said the WHO’s European director, Zsuzsanna Jakab.
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.
A report published by the European Commission last year and compiled by a team led by Larson found that measles immunization coverage has fallen in 12 EU countries since 2010, and that seven out of the 10 countries with the lowest vaccine confidence in the world are in Europe.