What did he say right before that remark?
If [5:5] then whatever he said right before it, is something he wanted communicated loudly and clearly.
I 'rewound' the presser to 56:55. Here is what President Trump said:
"The average development timeline for the vaccine, including clinical tests and manufacturing, can take 8 to 12 years. Through Operation Warp Speed, we're doing it in less than one year. If you had a different administration with different people, what we've done would have taken, in my opinion, three, four, five years and it would have been in the FDA forever. This is five times faster than the fastest prior vaccine development in history - five times faster - say it again - five times faster. Nobody can believe it, actually."/P>
This portion of his remarks starts at 56:55 from https://youtu.be/JGgaJOnZEs8 as posted on The Hill.