Did guns or vaccines save more lives in 2021?

[Angrboda]

‘Defensive gun use’ is not the same as ‘lives saved by guns’.

Boru

So if no other study even tried to estimate the number of lives saved by guns each year in the US... shouldn't we go with the Gary Kleck's study that estimated it to be around 300'000? The burden of proof is on somebody to demonstrate that Gary Kleck's study is wrong, that, if you control for various biases, you get a different number. Since nobody demonstrated that, the burden of proof stays on people who claim Gary Kleck's study is wrong.

That's not how burden of proof works and is essentially an argument from ignorance. "Nobody has proved it wrong, therefore it is right."