A joint report by two UN agencies, WHO and Unicef say nearly 14 million children globally were not immunised against preventable diseases last year.
According to the report, more than half of these children are in Africa with those living in countries in conflict being the most affected.
Chief of Immunisation at Unicef Dr. Robin Nandy said some of the missed vaccines are against diseases like polio, measles, meningitis, diphtheria, tetanus and whooping cough. Children living in remote rural areas and urban slums are also said to be vulnerable.
Nigeria, DR Congo, Ethiopia, Chad, Central African Republic and South Sudan are some of the African countries with high numbers of children who have not been vaccinated.
The report also warns that the number of children likely to miss vaccinations this year could double as a result of disruption to immunisation services due to the coronavirus pandemic.
So far, Angola, Ethiopia and Burkina Faso are among the few countries that have resumed mass vaccinations following strict guidelines.