You shouldn't be optimistic. You should understand the reality of the situation. How many virus affect humans? How many have a vaccine? How many have a single shot vaccine? How long did these vaccines take to produce? How many immunosuppressive virus have vaccines? You can find all this info online.

And then you have,

How long are the antibodies in the system? How many reups (boosts) does it take? HIV doesn't leave the body. Can you imagine a virus that can spread by breathing or sneezing that never leaves the body and shuts down your immune system?

The answers to these questions are not optimistic. The world is trying to do something that has never been done before and that has been attempted many, many times in the past.

I understand why people want to see the light at the end of the tunnel but it isn't good to go running towards it until you are sure what it is.