Immunization gaps threaten gains on measles
Measles outbreaks in the World Health Organization (WHO) Western Pacific Region are putting babies, children and young people at risk and threatening progress towards wiping out the disease.
The Region had historically low levels of measles cases and no major outbreaks in 2017. This landmark decline was achieved through steady efforts to vaccinate all children against measles, but last year, measles cases in the Region increased by 250%, and more than two-thirds of cases were in the Philippines. So far this year, the Philippines has reported 23 000 cases with 333 deaths — already more than all of last year. Tragically, most of the cases were among children under 5 years old.
Measles can cause debilitating complications, including encephalitis, severe diarrhoea and dehydration, pneumonia, ear infections and permanent vision loss.
“In recent months, we’ve seen how swiftly and easily measles can make a comeback in communities where not enough children have been immunized,” said WHO Regional Director for the Western Pacific Takeshi Kasai.
Nine countries and areas in the Region have been verified as having eliminated measles: Australia, Brunei Darussalam, Cambodia, Hong Kong SAR (China), Japan, Macao SAR (China), New Zealand, the Republic of Korea and Singapore. Elimination means there has been no prolonged local transmission of the virus for at least three years.
But even in countries where measles has been eliminated, as long as the virus is circulating elsewhere, people who are not immunized remain at risk of infection from an imported case. This, in turn can lead to an outbreak or re-establishment of transmission.
So far this year, Australia, Cambodia, China, Hong Kong SAR (China), Japan, the Lao People’s Democratic Republic, New Zealand, the Republic of Korea, Singapore and Viet Nam have all recorded measles cases.
“The resurgence of measles around the world has resulted in increased importation of the virus to several countries in our Region,” explained Dr Kasai. “What we want to stop is large-scale outbreaks resulting from those importations.”
Threat of outbreaks continues
Everybody should be vaccinated in all countries, whether or not they have achieved elimination, according to WHO guidelines. For a community to be protected, at least 95% of children must receive two doses of measles vaccine.
“Measles spreads like wildfire,” Dr Kasai explained. “It is the most contagious human disease, and it’s very good at seeking out and spreading among even small groups of people who are not immune.”
Since 2000, more than 21 million lives have been saved worldwide through measles immunization. In 2017 in the Western Pacific Region, 97% of children received a first dose of measles vaccine (compared to 85% in 2000), and 94% got the required second dose (compared to 2% in 2000).
Need to reach unvaccinated children
Although every country in the Region has committed to eliminating measles, some populations are still missed by immunization programmes. The lack of national strategies and efforts to increase access to vaccination are part of the problem, especially in hard-to-reach areas. Misconceptions about the effectiveness or safety of vaccines can also complicate efforts to vaccinate children.
WHO supports countries across the Region in efforts to vaccinate all children and strengthen their outbreak preparation and response. The Organization also encourages countries to address the reasons why children are not being vaccinated in some communities by combating misinformation and improving understanding of the importance and safety of vaccines.
In 2018, WHO published a Regional Strategy and Plan of Action for Measles and Rubella Elimination in the Western Pacific. The Plan assists countries in strengthening immunization programmes and developing national action plans for achieving the shared goal of measles elimination.