A year after COVID-19 hit the world scene, researchers are still working toward a safe and effective vaccine. Several show promise. But getting medicine to billions of people safely is challenging. Money shortages, transportation limitations, and—in developing parts of the world—lack of refrigeration complicate the task.

Currently, over 100 coronavirus vaccines are in testing. If all goes well, researchers will find one or more to help stop coronavirus infections. After that, timely and safe vaccine delivery will be crucial.

Keeping vaccines at low, stable temperatures from the time they’re made until they’re administered (the “cold chain”) is difficult. So far, the most promising vaccines must be stored at 25 to 46 degrees Fahrenheit. Some even require ultracold temperatures of around -94º F.

Temps like that require mobile cooling units, reliable electricity, and advanced planning. Experts call the temperature requirement problem the “cold chain hurdle.”

Cracks in the global cold chain start as vaccines leave the factory. Container ships aren’t equipped to refrigerate medical products. Shipping by air is costly, and air traffic is only now rebounding from pandemic-related closures.

Even if a vaccine arrives safely, experts say that many parts of the world lack the refrigeration to keep it safe. This includes most of Central Asia, much of India, most of Latin America, and all but a tiny corner of Africa.

Maintaining this chilly chain for coronavirus vaccines won’t be easy even in wealthy countries. It is yet another pandemic problem exacerbating the crisis for poor ones.

Poor people more often live and work in crowded conditions. The virus spreads readily among dense populations. The poor have little access to medications and pure oxygen for COVID-19 treatment. Their health systems lack capacity for large-scale testing. Now add the cold chain hurdle.

World Bank president David Malpass says it will be important for “developing countries [to] have fair and equal access to vaccines.” His view is a good reminder of a biblical concept: “Whoever oppresses a poor man insults his Maker, but he who is generous to the needy honors Him.” (Proverbs 14:31)

To uphold the cold chain in poorer nations, international organizations have installed tens of thousands of solar-powered vaccine refrigerators. The effort may still not be enough.

Healthcare researcher Tinglong Dai says creativity is needed to keep the cold chain unbroken globally.

So far, that creativity includes drone delivery and temperature-sensitive labels. They change color when a vaccine is exposed to heat too long. Dai says, “If people can figure out how to transport ice cream, they can transport vaccines.”