Nearly one in 10 infants worldwide did not receive any vaccination last year, putting them at a serious risk of contracting potentially fatal but preventable diseases.

A new report published by the World Health Organization and the UN children's agency, Unicef, says the rate of full immunization has stalled since 2010.

The report analyses immunization coverage in 194 countries across the world.

Eight countries, most of them in Africa, had less than half of their infants vaccinated last year. They include Nigeria, Central African Republic, Chad, Equatorial Guinea, Somalia and South Sudan.

This means that while some diseases such as measles and polio can now be prevented and potentially eliminated, there is still the possibility of outbreaks, leading to disability or death.

The uptake of recently introduced vaccines against leading childhood killers like pneumonia and diarrhoea is also low in many countries.

Unicef's Chief of Immunizations - Dr Robin Nandy - said bringing life-saving vaccines to the poorest communities must be considered a top priority.