Why not? Bidding should be time based to provide better incentives for the companies to spend money on factories.
What's the odds that we're going to have another pandemic in the next 10 years that has nRNA vaccine?
There's no need for massive production capacity other than during a global pandemic, and you probably don't know what you need, supply chains etc. until the time of production or thereabouts.
So - the money won't go into building out production capacity for something, when we don't know what that something is, it's constituent parts, or what technologies will be utilized.
The amount we're spending on productionizing vaccines is nothing compared to the damage the virus creates every day.
Businesses a failing every day, and when they go bankrupt they won't be able to come back.
Spending more on vaccines now probably won't help us create more vaccines 'the next time'.
Other things, such as government support for spending more on vaccines overall - this might help.
A bidding war (probably) would be profit capture for those selling vaccines, but won't actually raise the amount of available (in the short-term).
Since most timelines are less than 2 years, the time to build a factory can be around that in the States (or even more).