What do we know about the COVID-19 (coronavirus) vaccine?

Unchallenged

The US government has agreed a multi-billion dollar deal to buy COVID-19 vaccines from Pfizer.

The US government has agreed to buy 100 million doses of Pfizer's novel coronavirus vaccine (being developed with German biotech firm, BioNTech) for $1.95 billion. That works out at about $20 per dose.

Sources