Is the fact that the vaccine is "proprietary" relevant to the efficacy? Would a non proprietary vaccine be ok?

Of course, less money (no patents, etc), less interests and less non relevant choices being made (e.g buying endless supply of quinine because something) . Heck if actual mild cold could cause mass immunity, the cold virus is it's own distribution mechanism. No need for all the syringes and other logistics.

Of course this is all hand waving, but the point is we shouldn't automatically think that a man made vaccine is a much better solution.

> we shouldn't automatically think

Ah yes, we surely shouldn't automatically about anything. We should use reason and data.

We should, we don't. There are great forces working on making you think certain ways by emphasizing certain data, and push messages that promote certain reason making.

The more money is at stake the greater force is applied. The last few years have proven what a devastating effect it had on our ability to discuss and think reasonably about anything.