The US Food and Drug Administration made public its guidance for issuing emergency approval for a Covid-19 vaccine, making it clear it wants to see follow-up two months after trial volunteers have their second dose.
It is therefore unlikely for President Donald Trump's administration to have a vaccine on the market before the 3 November election, something the president frequently says is on the cards. "Data from Phase 3 studies should include a median follow-up duration of at least two months after completion of the full vaccination regimen to help provide adequate information to assess a vaccine's benefit-risk profile," the document said.