evidence: After SARS-CoV-2 (the virus that causes COVID) was discovered, vaccine development moved very quickly. In February 2020 the first batch of vaccines was completed (from Moderna) and the first clinical trials began in March. [...] While scientists had been working on mRNA vaccines for decades before the COVID pandemic, the COVID shots from Pfizer/BioNTech and Moderna were the first mRNA vaccines to be approved for human use. [...] Developing vaccines for COVID was a huge challenge, but one that can mostly be judged a success. Research has estimated COVID vaccines saved 14.4 million lives across 185 countries in just their first year.