Moderna Inc's experimental COVID-19 vaccine is more stable than expected at temperatures that ordinary refrigerators can provide and can be distributed using existing cold-chain shipping and storage infrastructure.

That opens the door for its early use in hard-to-reach places that might not be appropriate for Pfizer Inc's vaccine, which needs ultra-cold storage.

Why has access to life-saving vaccines been so unequal and could the coronavirus pandemic lead countries to unite around an affordable vaccine?

Even before COVID-19 hit, access to vaccines was deeply unequal with around 20 million children not receiving vaccines that could save them from serious diseases, death, disability, and ill health, according to the World Health Organization (WHO).

The cost of vaccinating a child against diphtheria, whooping cough, hepatitis B, tetanus, pneumonia, polio, and rotavirus was $15.90 in 2018, according to Gavi, the Vaccine Alliance.

While this may not seem much, this is still beyond the reach of many poor households.

Many poor countries lack reliable electricity and cold storage, two elements crucial to keep vaccines effective, and sometimes there are not enough healthcare professionals to administer the vaccines.

The stability of a country also plays an important role in whether people can access vaccines.

For example, two-thirds of unvaccinated children live in fragile countries or those affected by conflict, according to UNICEF.

Read the full article about COVID-19 vaccine inequality by Thin Lei Win and Tom Finn at Global Citizen.