We have a plan to roll it out as quickly as Johnson and Johnson can make it. But the truth is, no matter how fast they go, it's never gonna feel fast enough. The number out of the gate, meaning right after an authorization, be closer to 10 million. Now we're hearing four million. How's the public to make sense of that? We don't ultimately control the distribution and the volumes of the vaccines and final vital form. We're playing that middle step, making a new vaccine by the millions. It was always going to be an impressive feat. Shaun Kirk is the executive vice president of manufacturing and technical operations at Emergent Bio Solutions, and right now he feels the weight of the world on his shoulders can't sacrifice safety and quality for speed. And it's his job to strike that balance. What is the biggest hurdle then to scaling up? The bottleneck is often time, and these things just don't happen overnight. It can be a multi year time frame that we've undertaken, unfortunately, been able to compress that down. Emergent Bio Solutions is one of Johnson and Johnson's manufacturing partners, and its sprawling 112,000 square foot facility in Baltimore. It plays the key role of actually producing the viral vectors for the vaccine, basically the part that makes it work. What limits the capacity here? We're dependent upon a variety of different critical suppliers who also are rallying to the cause. So the entirety of this industrial orchestration, if you will, is very significant, and it's very complex. For starters, they have to grow the tissue cultures and these large reactors, so they're dealing with actual living organisms. They have to ensure they have all the proper nutrients they need to grow and then go through the purification steps to remove any debris. The manufacturing of biologic vaccine processes like these typically takes several weeks upwards of a month. What's important to note is that we are in a cadence, which means we don't wait for a single lot to move all the way through before we initiate another lot. After all, that, the newly manufactured vaccine is frozen and shipped more than 600 miles to another company, cattle, and that's in Bloomington, Indiana. What happens there? Fill and finish, and then every single vial is visually inspected. Hundreds per minute will pass through this process. It's fast, a breakneck speed, Kirk says. But again, in the middle of a pandemic, nothing is fast enough. We expect to reach the maximum, that commercial cadence. But we'll always look for opportunities to further refine and partnership with our customers to tease out as many doses as possible. When they say a billion doses, potentially by the end of 2021. That number sounds reasonable to you based on what you know. But suffice it to say we've got a little bit farther to go to get there. But that's all according to the plan and contracts that we have with Johnson and Johnson, every dose, every vial can still make a difference for the billions of people around the world waiting for their shot at protection. Dr. Sanjay Gupta, CNN reporting.