Immunizations prevent 2 million to 3 million deaths around the world each year, according to UNICEF. However, due to lack of funding, misinformation, and war and violence, many still do not receive vaccines for preventable, fatal childhood diseases.

In light of this year’s World Immunization Week 2016, UNICEF, the WHO and other civil society organizations aim to refocus public attention on the importance of vaccination for all of the world’s children.

“Immunization is one of the main reasons global child mortality has plummeted since 1990, yet tragically an estimated 1.5 million children still die every year from a disease that could have been easily prevented by a vaccine,” said Caryl M. Stern, president and CEO of the U.S. Fund for UNICEF, in a statement. “We know the challenges – poverty, conflict, misinformation and the difficulty in reaching the most remote and marginalized communities – but we owe it to the world’s children to overcome these barriers.”

Of the world’s estimated 18.5 million infants not receiving routine immunizations for preventable diseases like diphtheria, pertussis and tetanus, 11.5 million live in countries affected by conflict. In Syria alone, wartime conflict caused immunization rates to drop from 80 percent in 2010 to 43 percent in 2014.

Not surprisingly, lack of funding is also an enormous barrier in low-income countries without the means to adequately fund public health systems. The most extreme comparison is seen between the country with the highest individual health expenditure, Switzerland, which spent $9,674 (USD) per person in 2014, and the Democratic Republic of Congo, which spent just $12 per person that same year.

Still, the effort to expand global coverage of immunizations has seen remarkable progress in the last few years. The Americas became the first region to eradicate rubella, a contagious viral disease that can cause multiple birth defects as well as fetal death, and tetanus was eliminated in three countries.

The last few decades have also seen notable strides in the eradication of polio, reducing the 350,000 cases of the virus in 1988 to just 359 in 2014. Last year, the WHO announced that polio was, for the first time, no longer endemic in Nigeria.

Now, UNICEF and other organizations are calling on countries and health systems to educate the public about the benefits of immunization, and to target vaccine funding to marginalized and conflict-stricken communities.

“The progress we have made is remarkable,” said Stern, “but we cannot afford to stall our efforts now.”