Here what's in the Pfizer and AstraZeneca jabs.
Gamaleas, AstraZeneca, and R-Pharm agreed on developing and implementing a clinical research program to assess the immunogenicity and safety of the combined use of one of the components Sputnik V vaccine Center.
Where the second dose of Vaxzevria is not given, no definitive recommendations on the use of a different vaccine for the second dose can be made at present see.