It was named after the satellite Sputnik 1 and the V is not a roman five but stands for victory, multiple sources consistently claim? Sounds reasonable that this was just PR propaganda to connect to prior great successes in Russia..
(Even without that knowledge I'd find this theory a bit far fetched, there could be many other good reasons for that naming).
"Sputnik" is a regular Russian word, which means "one who travels together with another" (s-put-nik s-=with, -put-=travel/road/journey, -nik=somebody).
Victory is Latin word. Russian word for victory is "pobeda" (po-beda po-=after, -beda=bad/something very different from good, "after bad times").
It looks like 5 in the name is from Ad5 component of vaccine.
Moreover, the vaccine produced by Vector is called EpiVacCorona[0].
(Even without that knowledge I'd find this theory a bit far fetched, there could be many other good reasons for that naming).