Despite President Donald Trump’s promises of a vaccine next month and pundits’ speculation about how an “October surprise” could upend the presidential campaign, any potential vaccine would have to clear a slew of scientific and bureaucratic hurdles in record time.

In short, it would take a miracle.

We talked to companies, regulators, scientific advisers and analysts and reviewed hundreds of pages of transcripts and study protocols to understand all the steps needed for a coronavirus vaccine to be scientifically validated and cleared for public use. As you’ll see, it’s a long shot in 38 days.

Read more at ProPublica.