More than 117 million children could miss out on immunisation against measles as the Covid-19 pandemic forces social distancing and piles pressure on health services, United Nations health agencies warned on Tuesday.
Measles immunisation campaigns in 24 countries have already been delayed, and more will be postponed, potentially putting children in 37 countries at risk, according to the Measles & Rubella Initiative (M&RI), which is backed by the World Health Organization, the UN children's fund UNICEF and others.
"If the difficult choice to pause vaccination is made due to the spread of Covid-19, we urge leaders to intensify efforts to track unvaccinated children, so that the most vulnerable populations can be provided with measles vaccines as soon as it becomes possible to do so," the group said in a statement.
"While we know there will be many demands on health systems and frontline workers during and beyond the threat of Covid-19, delivering all immunisation services, including measles vaccines, is essential to saving lives."
The respiratory disease Covid-19 has killed more than 113,000 people and left countries around the world in virtual lockdown as they try to halt the spread of the novel coronavirus that causes it.
But in its shadow, a surge in measles outbreaks poses another major global health threat.
The World Health Organization (WHO) said in December that measles had infected nearly 10 million people in 2018 and killed 140,000, mostly children, in what it described as "an outrage".
The viral disease is highly contagious but can be prevented by mass immunisation, which would normally mean babies and children being vaccinated as part of routine health services.
With the fight against Covid-19 in most countries focused on keeping health workers safe from infection and imposing strict social distancing measures, the WHO has recommended that governments temporarily pause preventive immunisation campaigns, such as those against measles, where there is no active outbreak of a vaccine-preventable disease.
In many parts of Africa, medical aid projects that might normally include measles and other vaccine campaigns have stalled as countries have closed their borders and limited routine health services due to the pandemic.
The M&RI group said it supports the need to protect communities and health workers from Covid-19, but warned that this should not mean that children permanently miss out.
"Urgent efforts must be taken now ... to prepare to close the immunity gaps that the measles virus will exploit," it said.