In a report on global efforts to "make measles history", the United Nations children's fund, the World Health Organization and other bodies said fight was being hampered not by a lack of tools or knowledge, but a lack of political will to get every child immunized against the highly infectious disease.

"Without this commitment, children will continue to die from a disease that is easy and cheap to prevent," said Robin Nandy, UNICEF's head of immunization.

Mass measles vaccination campaigns and a global increase in routine vaccine coverage saved an estimated 20.3 million young lives between 2000 and 2015, the report said.

But coverage is patchy, and in some countries the majority of children are not vaccinated. In 2015, around 20 million babies missed their measles shots and an estimated 134,000 children died from the disease.

The Democratic Republic of the Congo, Ethiopia, India, Indonesia, Nigeria and Pakistan account for half of the unvaccinated babies and 75 percent of the measles deaths.

Measles is a highly contagious virus that spreads through direct contact and through the air. It is one of the biggest killers of children worldwide, but can be prevented with two doses of a widely available and inexpensive vaccine.

According to the report, published by UNICEF, the WHO, the GAVI vaccines alliance and the U.S. Centers for Disease Control and Prevention, outbreaks of measles in various countries – caused by gaps in immunization – are still a major problem.

Seth Berkley, GAVI's chief executive, urged governments to recognize the threat of "one of the world's most deadly vaccine-preventable childhood killers" and act to contain it.

"We need strong commitments from countries and partners to boost routine immunization coverage and to strengthen surveillance systems," he said.

In 2015, large outbreaks were reported in Egypt, Ethiopia, Germany, Kyrgyzstan and Mongolia, the report said. The epidemics in Germany and Mongolia affected older people, highlighting the need to vaccinate young adults who missed out on measles jabs.

Measles also tends to flare up during conflicts or humanitarian emergencies when vaccination schedules are disrupted. Last year, outbreaks were reported in Nigeria, Somalia and South Sudan.