Normally one of the possibilities of regulatory oversight is that you go into a meeting hoping your drug is approved, but the regulators are concerned about X. "Go away and check X" says the regulator, "this isn't a No, but it also isn't a Yes, we want to understand X before we decide". Maybe it'll take 12-18 months to set up and run experiments to answer X.
Regulators can decide they're uneasy about potential for birth defects, or side effects with particular other drugs you never tested, or any number of issues. Sometimes a pharmaceutical company just hoped not to be asked, and other times the concern comes out of the blue.
But if we're fast-tracking approval, anything that isn't a red flag won't get in the way. That unavoidably means higher risk to patients overall. Since the virus kills a lot of people every day everywhere it hasn't been eliminated it makes sense to take that risk, but governments (accountable to their citizens) get to decide that, not drug companies.
Regulators can decide they're uneasy about potential for birth defects, or side effects with particular other drugs you never tested, or any number of issues. Sometimes a pharmaceutical company just hoped not to be asked, and other times the concern comes out of the blue.
But if we're fast-tracking approval, anything that isn't a red flag won't get in the way. That unavoidably means higher risk to patients overall. Since the virus kills a lot of people every day everywhere it hasn't been eliminated it makes sense to take that risk, but governments (accountable to their citizens) get to decide that, not drug companies.