Nigeria has the highest number of unvaccinated children in the world, according to the World Health Organisation (WHO).
In a report released on Monday, the organisation said a total of 19.9 million children miss vaccination yearly.
It said 4 million children in this category are Nigerians.
The major disadvantage of not being vaccinated is high susceptibility to a disease outbreak. The unvaccinated fellow’s immune system is unable to identify and neutralise the disease causing agent virus or bacteria.
The report said 60 percent of unvaccinated children are typically based in 10 countries.
With 2.9 million, India comes next to Nigeria, followed by Pakistan with 1.3 million, Indonesia (1 million) and Iraq (450,000).
The other African countries named in the report are Ethiopia with 850,000 Democratic Republic of Congo (600,000), Angola (560,000) and South Africa (390,000).
Last month, Nigeria overtook India as the country with the highest number of poor individuals.
According to Brookings Institute, a century-old American research group, 87 million people out of 198 million Nigerians live in poverty.
The Nigerian government had discarded the World Poverty Report on the grounds that the indicators used were obtained when it was in recession.