The UK has approved use of the Pfizer/BioNTech vaccine and 800,000 doses will be available, mostly at hospitals, by the weekend for administration probably starting on Monday.
Russia, which has vaccinated about 100,000 in Sputnik V test phase, will begin delivering vaccinations next week. They have about 2 million doses pre-manufactured.
The U.S. is expected to begin rolling out the Pfizer/BioNTech vaccine by Dec 12th and the Moderna vaccine, perhaps about one week later.
As I have pointed out, however, at 2-3 million vaccinations per day (eventually and seven days per week), that will take up to several months to reach half of the U.S. population.