We’ll Need More Than One Vaccine to Beat the Pandemic

On Monday, a press release from the transnational pharmaceutical company Pfizer dropped a rare spark of hope into the ongoing misery of the Covid-19 pandemic. Yes, new infections have hit an all-time high in the United States, and, yes, cities and states around the world are walking back their reopenings. But Pfizer says it has results from a massive clinical trial showing that its vaccine against the disease works, and works well. The release touted “a vaccine efficacy rate above 90 percent,” and it announced the company’s intention to seek from the US Food and Drug Administration an authorization to start giving people shots. The company’s ready to make 50 million doses this year and 1.3 billion doses in 2021.

That’s an ember of hope, but it’s sitting under a bucket of cold water, ready to pour. The Pfizer vaccine is finicky—hard to make, transport, and deliver. Because of desperate need, it’s in short supply even before it becomes available—1.3 billion doses is several billion short of what the world needs. The press release wasn’t peer-reviewed science, and it lacked critical details about how the vaccine works, and on whom. Even the simple fact of this vaccine’s existence, some analysts have argued, might jeopardize the testing and success of potentially better vaccines down the line, a case of the imperfect being the enemy of the good.

Before the ember dies out completely, here’s a theory: No. The Pfizer vaccine’s imperfections make it a perfect prime mover, because if it works as well as the company says, it’ll help people now and require research into more, better, different vaccines for later. All the things nobody knows about the Pfizer vaccine mean that the door is wide open. “Whether its effects are durable, whether it’s effective in the elderly, whether it has safety issues, the cold chain issues, the ability to have access,” says Wayne Koff, president and CEO of the nonprofit Human Vaccines Project, “all that points to the need for a number of vaccines.”

Working with a smaller company called BioNTech, Pfizer moved off the starting block fast, and without the money from the US Operation Warp Speed program that funded other drug companies’ trials. This vaccine (like another candidate made by the company Moderna) is actually a tailored bit of genetic material called messenger RNA; give it to people, and the mRNA acts like biological software, teaching cells to manufacture the “spike” protein on the outer coat of the virus that causes Covid-19. Those people’s immune systems then learn to recognize and attack the spike, which gives them the ability to fight the virus. It’s a cool idea, and as my colleague Megan Molteni has written, it could change the future of vaccinology and infectious disease.

But this is the first mRNA vaccine, and it turns out to be a precious little snowflake. Pfizer’s vaccine has to be stored and shipped at ultracold temperatures, less than 80 degrees below zero—it’ll keep for a few days at higher but still very cold conditions. And it needs vials made of a special glass that’s able to tolerate the freezing temperatures. (This is neat, actually—the key is that the glass is low in boron, exactly the opposite of famously temperature-change-tolerant Pyrex glass, which is a mix of boron and silicon dioxide. The glassmaker Corning has a $204 million contract with the government to make it, and cut a deal in May to provide it to Pfizer. Whether they can make enough is the tricky part.)

All that shipping and freezing requires a level of technical sophistication that, for now at least, mostly exists in hospitals and labs—posing significant logistical challenges in rural areas and in the developing world. These are the “cold chain” problems that Koff mentioned, the problem of refrigerated shipping. (A critical Ebola vaccine needs the same deep freeze, and engineers stepped up to create specialized coolers to transport it across western Africa—but that was a pandemic that affected tens of thousands of people, not billions, and the people who made the coolers have since gotten out of the cold-chain innovation game.)