Mass Producing A Coronavirus Vaccine?

[BFritz21]

Everyone is in a rush to produce a vaccine for Covid-19, and who knows if it will ever pan out but it looks promising.

Then again, you hear different projections from day-to-day with some (most) saying one will be ready by December or January, I saw one recently saying October, some say never, or various other timelines.

They're all saying that they're ramping up production to be able to produce x number of vaccines by a certain date, but why don't they just join together once a vaccine is ready and combine efforts to produce said vaccine? I get it that they're all trying to make money, but this is a global pandemic, so why wouldn't they say "you produce this and we'll give you 10% of the profit"?

That means that they're still making money but producing more of it, which means more money and a better outcome for the public?

Or even if they just rent out other factories (if they're produced in factories) from other drug makers where they could produce the vaccine in mass quantities.

Does anyone know why this isn't being considered or is it not possible?

Is capitalism and greed the simple answer?