Cuba has developed a therapeutic vaccine against lung cancer.

Lung cancer is the number four killer in Cuba, and with economic and political constraints, Cuban medical researchers have had to get creative with how they fight the disease. The vaccine called Cimavax, which is inexpensive to make and store, has been available for free in Cuba since 2011. A trial from 2008 revealed that the lung cancer patients who took the vaccine lived four to six months longer on average than those who didn't take the vaccine.

In its current form, the drug won't be a game changer, but doctors in the US are hoping to work collaboratively with the developers in Cuba to improve the drug and begin clinical trials with the FDA, and believe that eventually the drug could be used preventatively like a traditional vaccine.

Last month, an agreement was met that will allow clinical trials to begin in the US, but for collaborative research to continue, Congress will need to lift the Cuban embargo.