According to global agencies, almost 20 million children missed out on potentially life-saving vaccinations last year.

Almost 20 million children last year did not receive potentially life-saving vaccinations, according to United Nations agencies, calling for an increase in efforts to shield minors from preventable illnesses such as measles.

In annual report released on Monday, the World Health Organization (WHO) and the UN children’s agency (UNICEF) said 19.4 million children were “not fully vaccinated” in 2018, an increase from 18.7 million the year before and about 18.5 million in 2016.

According to the WHO, the increase pointed to a “dangerous stagnation of global vaccination rates, due to conflict, inequality and complacency”.

“Vaccines are one of our most important tools for preventing outbreaks and keeping the world safe,” Tedros Adhanom Ghebreyesus, the WHO’s director-general, said in a statement.

“It’s often those who are most at risk – the poorest, the most marginalised, those touched by conflict or forced from their homes – who are persistently missed,” he added. “Far too many are left behind.”

The WHO named several examples of diseases that could have higher prevention rates, including measles, diphtheria, tetanus and pertussis (whooping cough).

According to the health agency, vaccination rates for these diseases have stalled at 86 percent since 2010, which it rated as “not sufficient”.

Some 350,000 measles cases were reported globally last year – more than double the 2017 number, a “real-time indicator” of the quest to expand vaccine coverage, UNICEF chief Henrietta Fore said in a statement.

The resurgence of that preventable disease is partially to blame on the so-called “anti-vax” movement, which spreads false claims that vaccinations are the cause for, among other things, autism.

As a result of this campaign, many people, especially in the United States but also in Europe, choose not to vaccinate their children against measles, decreasing the vaccination rate and endangering people around them.

A number of countries with coverage formerly well above 90 percent, have regressed, the data showed.

In Brazil, application of the first dose of a measles vaccine fell to 84 percent last year from a high of 99 percent.

Ecuador saw a similar drop for the first measles dose, while in the Philippines coverage fell from 87 percent to 67 percent from 2010 to 2018.

The “reasons for backsliding include complacency, lack of investment in public health, conflict, and in some places lack of trust in vaccines”, the WHO said.

“Measles is a real-time indicator of where we have more work to do to fight preventable diseases,” Fore said.

“An outbreak points to communities that are missing out on vaccines … [and] we have to exhaust every effort to immunise every child.”

The WHO noted that there was also some progress, as vaccinations for the human papillomavirus (HPV) vaccine were added to their national programmes, thus making it available to one in three girls worldwide.

The countries that added this vaccination to their programme, however, were mainly wealthy countries.