Vulnerable people should get those vaccines as soon as it is safe to do so.

As countries around the world shut down to fight the COVID-19 pandemic, 117 million kids are at risk of missing the measles vaccine, top health organizations say.

Measles immunization campaigns in 24 countries have already been postponed, and more are expected to be delayed, according to the Measles & Rubella Initiative, a health partnership that includes the World Health Organization, the U.S. Centers for Disease Control and Prevention and United Nations Foundation.

In March, the WHO released new guidelines in the face of the COVID-19, recommending that governments temporarily pause preventative vaccine campaigns, such as measles immunizations, as long as there’s no active measles outbreak in that area.

Governments should calculate the risk of temporarily delaying vaccines versus the risk of COVID-19 transmissions within their jurisdictions.

“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 initiative said in a statement.

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“While we know there will be many demands on health systems and frontline workers during and beyond the threat of COVID-19, delivering all immunization services, including measles vaccines, is essential to saving lives that would otherwise be lost to vaccine-preventable diseases.”

More than 140,000 people around the world died of the measles in 2018, most of them children under the age of 5, according to WHO.

In comparison, more than 121,000 people have died so far during the ongoing COVID-19 pandemic.