Serious question (I'm not an expert) - Why would there be an imminent depression-like downturn when effective vaccines were announced < 1 month ago? I vaccines

Serious question (I'm not an expert) - Why would there be an imminent depression-like downturn when effective vaccines were announced < 1 month ago? I vaccines didn't exist, I would believe this but given they do, I can't image the future is not brighter.