Trump is desperate to come up with an October surprise, and is talking about having a vaccine approved for election day. Here are the Phase III trial lengths from Trial Site News:

Pharma Phase 3 COVID-19 Vaccine Study Duration (Start date to Est. Primary Completion)

Moderna (mRNA-1273).....................15 months
Pfizer/BioNTech (BNT162)................12 months
J&J (Janssen) (Ad26.COV2.S).............30 months
China National Biotech...................7 months
Sinovac (CoronaVac).....................14 months
University of Oxford (same as AZ).......15 months
AstraZeneca (AZD1222) in USA............3.5 months


Trial Site News

Even if AstraZeneca works like crazy, their completion date is December 2, 2020. Trump fan anti-vaxers are going to have a meltdown: Serve as a guinea pig for an untested vaccine, or disobey their orange lord and master.