Pfizer vaccine: How a company manufactures its millions of doses of Covid-19 vaccine

Pfizer / BioNTech’s overall goal is 2.5 billion doses by the end of the year.

Big bet

Pfizer reached its first milestones with a substantial initial investment, and it had no guarantees.

Pfizer was part of Operation Warp Speed ​​as a potential supplier of Covid-19 vaccines and had a purchase contract for 100 million initial doses. However, the company has not received federal funding for vaccine research or development.

So while Pfizer could reuse some of its equipment at its main manufacturing site in Kalamazoo, most of what currently exists did not exist a year ago.

“Pfizer spent at risk, almost $ 2 billion for the entire program. Since manufacture, my team has spent $ 500 million, before we even came out of clinical trials. So all of them completely at risk. We weren’t sure if we had a product that was going to work, ”McDermott said.

Before Pfizer decided on its final vaccine candidate, it was looking at four different options. This meant McDermott and his team had to be prepared to go in any direction.

“I’m pretty much thinking, we’re going to have dinner tonight, and we’ve got to make dessert, but I don’t know what dessert we have. So you just start buying ingredients,” he said. “Maybe we bake a cake, maybe we bake brownies. Bring the standard materials we need. So stocking that pantry was pretty expensive.”

According to McDermott, one of the biggest steps limiting the speed of this production has been the availability of raw materials and especially lipids, the fatty substance that safely harbors mRNA until it can reach our cells.

“Lipid nanoparticles have not been used in a large commercial product. The lipid suppliers were therefore not very important. So we’re working closely with them to increase lipid capacity and manufacture lipids at this Kalamazoo, Michigan site, ”McDermott says.

The heart of mRNA

Pfizer / BioNTech’s Covid-19 vaccine can simply be described as mRNA housed in a lipid coating, but the successful production of this vaccine by the millions comes down to something the size of a quarter.

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The heart of this whole machine is what’s called an impact jet mixer, ”McDermott said as he twirled it around his fingers.

The impact jet mixer, also known as the tea stirrer, works by simply pumping lipids on one side and mRNA on the other, forcing them to a pressure of 400 pounds. This is what creates the lipid nanoparticle which is essentially the vaccine.

These aren’t just any lipids, Pfizer / BioNTech had to design the right combination of four different lipids that would not only protect the mRNA on its way to the cells, but then release the mRNA once it got there.

While the process of creating lipid nanoparticles is nothing new, McDermott said the challenge is to scale up this process.

“The first time someone showed me this impact jet mixer, I said, ‘Can’t you be serious? For example, how could you put billions of doses in here? So my confidence level was actually pretty low. Not that it could be done, I knew it worked on this scale, but how could you multiply it? ”

McDermott’s first thought was to go bigger, to make a tea stirrer on a large scale to allow more volume to pass through. When that didn’t work, they ended up replicating quarter size mixers and implemented technology to ensure efficiency in order to increase production.

“There is a computer system that runs the whole device that ensures you have the precise amount of flow and pressure. And that has allowed us to increase production. Even though this size is small, we were able to really put to scale our original design of this machine. We are currently operating at four times its capacity. ”

Make it modular

Part of what allowed Pfizer to continue to make room for these new formulation suites was its strategy of using prefabricated constructions.

At its 1,300-acre facility in Kalamazoo, Pfizer installs approximately 13,000 square feet of modular rooms that are first built in Texas and then shipped to Kalamazoo.

“We planned to expand our formulation capacity. The question was, how can we do it quickly? If we built it wall by wall in place, it would have taken us a year. we could cut that in half, ”McDermott says.

Setting up each piece is surprisingly easy. With the help of compressed air – think of an air hockey table – you can just slide them into place. Then the chambers are ready to be connected to electricity, sterilized and put into service.

With each of these improvements, Pfizer says it went from 3 to 4 million doses of vaccine per week to 13 million doses per week. The company expects to double that number by the middle of the year. That will mean around 100 million doses per month and the ability to meet its target of 300 million total doses delivered to the US government by July.

And after

McDermott says the past 12 months have been “like nothing I’ve ever experienced in my career.”

“As a child, my father worked for NASA,” McDermott said. “He was fortunate to be at Mission Control in Houston when Neil Armstrong walked to the moon at this incredible time.

“I could never imagine having a moment like this in my life. Right? Like, what are the chances that something like this will ever happen again?”

Then came December 13, 2020 – the day the United States’ first coronavirus vaccine, the first step in ending the pandemic, left the facility.

“The day we shipped the first doses out of this site, it hit me like it was my moment,” McDermott said. “It was our moonshot.”

But McDermott says the vaccine supply is always on his mind and they need to prepare for the future – and that means variants of the coronavirus.

While there is no evidence that people immunized with Pfizer’s vaccine will be less protected against current variants, the company has started testing a third dose of its current vaccine.

Pfizer and BioNTech say they are also in ongoing discussions with regulators to potentially test a modified vaccine to protect against variants of concern in a Phase 1/2 study.

The next big step for the business is to be ready to pass it on to patients, if necessary.

Pfizer’s goal, McDermott says, is to be able to develop a new variant-specific vaccine, get it into production, and get it to patients within months.