The Russian Sputnik V vaccine [1] distinguishes itself from other two-dose Adenovirus vector vaccines [2] (Oxford–AstraZeneca and Chinese CanSino) by using diff

The Russian Sputnik V vaccine [1] distinguishes itself from other two-dose Adenovirus vector vaccines [2] (Oxford–AstraZeneca and Chinese CanSino) by using different vectors (Ad26 and Ad5) for each dose. The Johnson & Johnson vaccine [3] is an Ad26 single-vector single-dose vaccine. In my opinion, the outstanding question is production capacity. Given the supply chains and geopolitics involved, I think the rational choice is to get whatever approved vaccine is available to you as soon as possible. [1] https://en.wikipedia.org/wiki/Sputnik_V_COVID-19_vaccine https://en.wikipedia.org/wiki/Sputnik_V_COVID-19_vaccine [2] https://en.wikipedia.org/wiki/COVID-19_vaccine#Adenovirus_vector_vaccines https://en.wikipedia.org/wiki/COVID-19_vaccine#Adenovirus_ve... [3] https://en.wikipedia.org/wiki/Ad26.COV2.S https://en.wikipedia.org/wiki/Ad26.COV2.S