Which is the best Covid vaccine?

Pfizer, Moderna and Sputnik vaccines have very high efficacy rates: 95, 94, and 91 percent. But the reported efficacy of Covaxin* and Covishield are between 70 to 80 percent. (*Only interim results known for Covaxin as of now.) If you look at just these numbers, it’s natural to think that the first three vaccines are better. But, that is not correct... Let’s understand why.