https://www.vice.com/en_us/article/4adwe3/cold-chain-logistics-could-make-vaccinating-lower-income-countries-difficult

With recent announcements that the Pfizer and Moderna Covid-19 vaccines are 90 and 94.5 percent effective, many experts are showing a rare moment of optimism as the pandemic’s one year anniversary quickly approaches. 

They have reason to be. The effectiveness of the two vaccines is far above the FDA’s 50 percent cutoff point and they were developed at record speeds. This is partly because they both use cutting edge mRNA technology that places genetic code from the virus, rather than a piece of it, into the body to induce an immune response. Experts say that this technology also makes these vaccines cheaper, safer, and easier to produce than traditional vaccines.