The country of Yemen is experiencing a major health disaster — and help is not on the way.

Cholera, a contagious illness spread through contaminated water, has afflicted 313,000 people in Yemen, and the death toll exceeds 1,700, reports the Red Cross.

Last month, the World Health Organization (WHO) agreed to send 1 million doses of cholera vaccinations to Yemen, but the group announced this week that they will not ship the vaccines after all due to worsening civil war and the spread of the disease.

Read More: World’s Worst Cholera Outbreak Hits Yemen, UN Says

Christian Lindmeier, a spokesperson for WHO, says vaccination efforts in Yemen are difficult as they cannot be approached in the typical manner; violence, famine, and the logistics of war must be taken into consideration.

Yemen, which has been called the “world’s single largest humanitarian crisis” by the Red Cross, is now in the midst of “the worst cholera outbreak in the world”, according to WHO.  

However, due to these logistical challenges, WHO announced it will re-route the cholera vaccines to nations who may need them more urgently or can use them more effectively.

According to Jamie McGoldrick, the UN aid coordinator in Yemen, the conflict has made areas most affected by cholera inaccessible. He says that due to distribution challenges, vaccine shipments to Yeman are being “set aside” and transferred to countries where their use will be more successful.

Read More: Yemen’s Famine Is Beyond ‘the Point of No Return,’ UN Agency Warns

The outbreak, which began earlier this spring, has only been worsened by a health system crippled by a civil war that has claimed the lives of over 10,000 people.

Trying to cope with war, malnutrition, and cholera, underfunded aid programs are diverting funds originally allocated to famine relief to cholera prevention.

The WHO’s general director, Tedros Adhanom Ghebreyesus, is scheduled to brief the UN Security Council Wednesday via teleconference regarding the situation in Yemen.

It is anticipated his briefing will focus on the cholera outbreak, vaccine shipments, the functionality of Yemen’s medical facilities, and how The Humanitarian Response Plan for Yemen remains underfunded.

Although the conference in unlikely to change the WHO decision, council members may raise concerns and suggestions regarding the situation in Yemen and how recent violence in surrounding nations may further divert attention from the country’s plight.