It is outrageous that in the 21st century, vulnerable Syrians now risk being afflicted with polio. Its re-emergence in Syria, where the disease had been eradicated for 14 years, is a terrifying indication of what can happen when a country and its public health system fall apart under the weight of war.

There is no treatment for this highly contagious virus. It spreads indiscriminately and can most effectively be prevented through vaccination. The International Rescue Committee (IRC) and our partner aid organizations need an immediate humanitarian cease-fire to allow access for immunization campaigns. Any denial of medical care is a weapon of war against the Syrian people, particularly for the more than 5 million now displaced within their own country who are difficult to track and immunize.

The need for vaccinations for the hundreds of thousands of children living in desperate conditions inside Syria is critical. Polio can cripple or kill those affected by it, and those most at risk of infection are children under the age of fIve. We must act immediately: one out of 200 children infected with the polio virus develops paralysis. The other 199 that are infected do not develop the symptoms, but are spreading the virus and infecting others. The outbreak in Deir al-Zour threatens neighboring governorates where the IRC is providing life-saving medical care, as well as neighboring countries.

An immunization campaign is urgently needed in these regions. The IRC is ready to act, and can reach up to 300,000 people quickly, but we require safe access and supply. That’s why the IRC is calling on the World Health Organization and UNICEF to work with the Syrian government to make the oral polio vaccine available immediately, at the scale necessary.

Vaccination is the most effective way to limit the spread of polio, but simple hygiene measures can also help limit the spread of the virus while the vaccination campaign starts to roll out. So we are preparing an extensive hygiene campaign, including hygiene education and the provision of soap to 17,000 families at risk of infection in 20 villages across north-central Syria.

While the vaccine is effective and easily administered, it requires storage and transport at cool temperatures. The IRC already has a “cold chain” in Syria, and with the help of UNICEF, we can provide thermal boxes for vaccine transport. We have the organization and the technology ready to immunize people now against the disease, but we need an immediate guarantee of security for our health workers and supply.

The broader picture is equally worrying. We are able to deliver free healthcare to hundreds of thousands of Syrians, but the scale of the problem is greater than the innovative and heroic efforts that aid organizations are able to make. Doctors and aid workers with medical supplies are routinely arrested and kidnapped. We have an opportunity now to mitigate the spread of polio in Syria, but only if we gain secure access to all areas in need, and this requires cooperation from an increasingly broad and fractured set of actors in the region.

The humanitarian situation in Syria and the neighboring region continues to deteriorate, while political and military developments maintain the world’s focus. This outbreak of polio must serve as a wake-up call to the international community that the amount of misery, death and decay in the country remains immense. Polio must be the last disaster for Syria.