AstraZeneca developed its vaccine with Oxford University. Sputnik V was developed by the state-run Gamaleya Center in Moscow, and the Russian Direct Investment Fund bankrolled the project. The developers of Sputnik V proposed combining the shots to AstraZeneca in November, suggesting it could increase the effectiveness of the British vaccine. Early results have shown that combining the AstraZeneca vaccine with the Pfizer-BioNTech vaccine produces a strong immune response. A large U.S. study found the AstraZeneca shot to be about 79% effective in preventing symptomatic disease, but it may be slightly less effective against emerging variants, including the delta.

Source: ABC News July 27, 2021 12:45 UTC