Editor's Note: This story has been corrected to clarify that Pfizer has invested up to $1 billion to manufacture its COVID-19 drug. The story previously stated, incorrectly, that Pfizer had invested $2 billion. Pfizer has begun manufacturing its investigational oral COVID-19 drug at-risk so that if the drug is successful in clinical trials and ultimately authorized for emergency use by FDA, the company will be ready and able to supply significant quantities of the product around the...