Global measles deaths reached 207,000 in 2019, a 23-year high and a 50% increase from 2016, according to a new analysis by the World Health Organization (WHO) and the United States Centers for Disease Control and Prevention (CDC).

The report blames declining vaccination rates globally for the spike in both cases and deaths from a disease that public health officials had long assumed was on its way out — a virus that could likely be eradicated through a reliable vaccine, international coordination, and public buy-in.

Now that the COVID-19 pandemic has disrupted public health campaigns against a range of pathogens worldwide, experts fear that measles could once again entrench itself within vulnerable communities, ravaging lives in a way not seen for nearly a century.

Measles is a highly infectious respiratory virus that primarily affects children. While the symptoms of measles can generally be managed, malnourished and otherwise immunocompromised children can be killed by it.

The vast majority of measles deaths in 2019 could have been prevented if vaccination campaigns received adequate funding, according to Voice of America.

“It’s just hard for me to believe that kids are dying of a disease that we’ve had a great vaccine for, for 50 years,” Robb Linkins, an epidemiologist at the CDC, told the New York Times.

The new report says that the surge in measles cases had been anticipated for years because vaccination campaigns have wavered in recent years. Preventing a measles outbreak requires a vaccination rate of 95%, which establishes herd immunity within a population. Today, worldwide vaccination rates for the first dose of the measles shot is at 85% and rates for the second shot stand at 71%. 

“The big issue is not actually large holes in coverage, it's the stalling in coverage,” Dr. Natasha Crowcroft, senior technical advisor on measles and rubella at the WHO, told a press conference in Geneva on Thursday. “It's a bit like, you know, tinder for a forest fire — it reaches a point where an outbreak really takes off. And that's what we saw in 2019, with the almost explosive outbreaks in areas that have had inadequate coverage over many years.”

Hundreds of millions of children now receive no vaccine against measles and 94 million children this month alone will miss their scheduled shots, the report notes. 

Nine countries accounted for around 73% of measles cases in 2019: Central African Republic, the Democratic Republic of Congo, Georgia, Kazakhstan, Madagascar, North Macedonia, Samoa, Tonga, and Ukraine.

Still, some countries, like Ethiopia, have made significant strides in protecting their population against the virus in recent years.  

So far this year, measles cases have declined, but public health officials told the New York Times that the dip is due to significant underreporting. Because public health systems are so overwhelmingly focused on the COVID-19 pandemic, reporting systems and health care services for other illnesses have been paused. 

The disruptions caused by COVID-19 could reverberate for years and lead to a surge in other infectious diseases, including measles. 

Public health officials worry that some of the trends undermining the containment of measles could eventually thwart COVID-19 containment efforts, too. 

Growing skepticism of vaccines in high-income countries such as the US have already led to measles outbreaks. If vaccine skepticism grows, then public health campaigns could face deadly setbacks.