FDA documents are scheduled to be released for COVID-19 vaccines. In short, they are expected to lay out what seems at first blush to be a higher-than-expected bar given urgency to accelerate availability of a vaccine, and vs comments by Dr Fauci recently where he is saying he is optimistic one is available by early 2021. That said, one might expect FDA to retain stated and published high standards for any full approval.
In short - takeaway is "emergency use authorization" (EUA) of various vaccines is still the likely scenario given the stated timeline goals under Operation Warp Speed of January 2021 (see their timeline statement here) - and is likely - to accelerate availability of one or more by the winter (political pundits will say approval before Nov 3 election) or Fauci recent bookend comment by early 2021 (consistent w/ Operation Warp Speed plan).
We think "emergency use" is different than full approval. It will satisfy meeting the timelines to get vaccines available for controlled use and designated for high-risk populations (elderly, at risk/co-morbidities, front-line workers, etc.) or people willing to sign waivers and accept risk - while more full large, controlled, randomized efficacy Phase III data are continuing into 2021+. Emergency approval would be just a designation and based on "antibody data", safety, and other factors. As a reminder, Remdesivir has EUA in US after recent positive Phase III data (label here) and so did HCQ (which later got pulled).
As a reminder, MRNA, AZN, PFE/BNTX, are all reporting more data imminently and should look good - and are all planning or started Phase III placebo-controlled studies in 30,000 pts each to determine if the vaccine "prevents infection symptoms" vs placebo. MRNA is in a large Phase II (n=600) but the large Phase III's (30,000 each) are needed to demonstrate statistical powering for a reduction in symptomatic infection rate since infection rates are estimated to be very low for broad populations so statistics requires large numbers of volunteers.
In short, FDA documents are expected to essentially suggest approval requires: (1) greater than 50% infection benefit (ie the vaccine cuts infection rate in half vs placebo); this seems interesting given flu vaccines are only 30-70% effective in any given year per our experts (here); (2) generally can’t be approved on just antibody levels given it's not known what levels are deemed required to prevent infection. As a reminder, some scientists are under assumption that antibody "titer" levels of 75-150 would be at or above levels of convalescent sera (pts who resolved) and reasonable to "predict" it could be effective to prevent infection, but levels and durability are not known.