As of today, 13,071,925 doses have been distributed and 4,284,534 given(in the U.S.).
https://www.bloomberg.com/graphics/c...-distribution/
The two vaccines being used now, Moderna and Pfizer, both use a new vaccine approach involving messenger RNA. Their clinical trials reported up to 95% efficacy.
The next one to be approved should be AstraZeneca/Oxford vaccine. Their trials reported around 70% efficacy. This vaccine uses a “viral vector,” introducing a harmless virus—in this case a virus that causes the common cold in chimpanzees—modified with the SARS-CoV-2 virus spike protein to stimulate an immune response. The Oxford-AstraZeneca shot requires only standard refrigeration and will remain viable for up to six months. It supposed to be a lot cheaper too. However a series of irregularities and omissions in the way AstraZeneca initially reported their trial data have eroded confidence in the reliability of their results. I’m guessing approval by March 2021.
Two more vaccines, the Novavax and the Johnson&Johnson, are currently in Phase 3 U.S. clinical trials and should be approved (if all goes well) by April 2021.