Representational photo.

NEW DELHI: India has 2.9 million children who have missed out on the first dose of measles vaccine between 2010 and 2017 despite over 80 per cent of immunisation coverage, the UNICEF said on Thursday.

India, with its large annual birth cohort of 25 million, is followed by Pakistan and Indonesia - 1.2 million each, and Ethiopia 1.1 million, it said, adding that the situation is "critical" in low and middle-income countries.

In 2017, for example, Nigeria had the highest number of children under one year of age who missed out on the first dose of vaccine, at nearly 4 million, the United Nations child health body said.

The United States topped the list of high-income countries with most children not receiving the first dose of the measles vaccine between 2010 and 2017 at more than 2.5 million.

It is followed by France and the United Kingdom, with over 600,000 and 500,000 unvaccinated infants, respectively, during the same period.

An estimated 169 million children missed out on the first dose of the measles vaccine between 2010 and 2017, or 21.1 million children a year on an average, the UNICEF said.

Widening pockets of unvaccinated children have created a pathway to the measles outbreak around the world.

"The ground for the global measles outbreaks we are witnessing today was laid years ago," UNICEF Executive Director Henrietta Fore said.

"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," Fore said.

In the first three months of this year, more than 1,10,000 measles cases were reported worldwide - up nearly 300 per cent from the same period last year. An estimated 1,10,000 people, most of them children, died from measles in 2017, a 22 per cent increase from the year before, the body said in a statement.

Two doses of measles vaccine are essential to protect children from the disease. However, due to lack of access, poor health systems, complacency, and in some cases fear or skepticism about vaccines, the global coverage of the first dose of the measles vaccine was reported at 85 per cent in 2017, a figure that has remained relatively constant over the last decade despite population growth.

Global coverage for the second dose is much lower at 67 per cent. The World Health Organization (WHO) recommends a threshold of 95 per cent immunisation coverage to achieve so-called 'herd immunity'.

"Worldwide coverage levels of the second dose of the measles vaccines are even more alarming. Of the top 20 countries, with the largest number of unvaccinated children in 2017, nine have not introduced the second dose," it said in the statement.

Twenty countries in sub-Saharan Africa have not introduced the necessary second dose in the national vaccination schedule, putting over 17 million infants a year at higher risk of measles during their childhood.

"Measles is far too contagious," said Fore, adding that "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".

