The Unicef has warned that millions of children are in danger of missing life-saving vaccines against measles, diphtheria and polio due to disruptions in immunization services caused by the Covid-19 pandemic.

Most countries had suspended mass polio immunization campaigns and 25 countries had postponed mass measles immunization campaigns, the Unicef said in a statement on Friday.

It added that even before the Covid-19 pandemic, measles, polio and other vaccines were out of reach every year for 20 million children below the age of one.

Over 13 million children below the age of one did not receive any vaccines at all in 2018, it added.

"The stakes have never been higher. As Covid-19 continues to spread globally, our life-saving work to provide children with vaccines is critical," Robin Nandy, Unicef Principal Adviser and Chief of Immunization, said.

"With disruptions in immunization services due to the Covid-19 pandemic, the fates of millions of young lives hang in the balance," he added.

An estimated 182 million children missed out on the first dose of the measles vaccine between 2010 and 2018, or 20.3 million children a year on average, according to a Unicef analysis.

This is because the global coverage of the first dose of measles stands only at 86 per cent, well below the 95 per cent needed to prevent measles outbreaks, said the statement.

Widening pockets of unvaccinated children led to alarming measles outbreaks in 2019, including in high-income countries like the US, UK and France.

Among low-income countries, the gaps in measles coverage before Covid-19 were already alarming, warned Unicef.

Between 2010 and 2018, Ethiopia had the highest number of children under one year of age who missed out on the first dose of measles, at nearly 10.9 million.

It was followed by the Democratic Republic of Congo (6.2 million), Afghanistan (3.8 million), Chad, Madagascar and Uganda with about 2.7 million each, said Unicef..