Millions of children in high- and low-income countries have missed the first dose of the measles vaccine since 2010, according to UNICEF. It said the numbers of children missing the second dose were "even more alarming."
Some 169 million children missed the first dose of the measles vaccine between 2010 and 2017, an annual average of 21.1 million per year, according to a report released Thursday by the UN's children's agency.
Two vaccine doses are needed to protect children from the acutely contagious disease, the United Nations Children's Fund (UNICEF) said in a statement on their website.
However, a "lack of access, poor health systems, complacency and in some cases fear or skepticism about vaccines" meant that 15% of children across the globe did not receive the first dose.
"Measles is far too contagious," said UNICEF Executive Director Henrietta Fore. "It is critical not only to increase coverage but also to sustain vaccination rates at the right doses to create an umbrella of immunity for everyone."
"The measles virus will always find unvaccinated children. If we are serious about averting the spread of this dangerous but preventable disease, we need to vaccinate every child, in rich and poor countries alike."
US first among high-income countries
Coverage for the first vaccine dose in high-income countries is 94%, but coverage for the second dose drops to 91%, according to UNICEF.
At nearly 2.6 million, the United States had by far the most cases of children who did not have the first vaccine dose between 2010 and 2017 among high-income countries. That is almost 30% more than the next four high-income countries combined.
Germany ranks eighth among high-income countries with 168,000 cases of children missing the first dose.
The situation is critical in low- and medium-income countries, UNICEF said. Nigeria had the highest number of children under the age of one who missed the first dose at 4 million.
UNICEF also said the number of children who had missed the second dose were "even more alarming," with only 67% of children receiving it in 2017.
Of the 20 countries with the largest numbers of unvaccinated children in 2018, nine have not introduced a second dose.
More than 110,000 measles cases were reported in the first three months of 2019, which UNICEF said was a 300% increase compared with the same period in 2018. Around 110,000 people died from measles in 2017, a 22% rise from the year before.