Wed. Sep 28th, 2022
Close-up photo of a gloved hand holding a small bottle of clear liquid.
enlarge A medical worker holds a bottle of a candidate COVID-19 vaccine developed by the University of Oxford, which is being tested in a trial in Soweto, South Africa.

On Monday, a press release from transnational pharmaceutical company Pfizer dropped a rare glimmer of hope in the lingering woes 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 stalling reopening. But Pfizer says it has results from a massive clinical trial showing that its vaccine against the disease works and works well. The release praised “more than 90 percent vaccine effectiveness,” and it announced the company’s intent to seek permission from the US Food and Drug Administration to give people injections. The company is poised to make 50 million doses this year and 1.3 billion doses by 2021.

That’s a ray of hope, but it’s under a bucket of cold water, ready to pour. The Pfizer vaccine is finicky: difficult to make, to transport and to deliver. Due to desperate need, it is in short supply before it becomes available – 1.3 billion doses are several billion less than what the world needs. The press release was not peer-reviewed science and was missing critical details about how the vaccine works and on whom. Even the simple fact of this vaccine’s existence, some analysts have argued, could jeopardize the testing and success of potentially better vaccines in the future, with the imperfect being the enemy of the good.

Before the ember dies out completely, here’s a theory: no. The imperfections of the Pfizer vaccine make it a perfect engine because if it works as well as the company says it will help people now and research is needed into more, better, different vaccines for later. All the things no one knows about the Pfizer vaccine leaves the door wide open. “Whether its effects are sustainable, whether it is effective in the elderly, whether it has safety issues, the cold chain issues, the ability to access it,” said Wayne Koff, president and CEO of the nonprofit Human Vaccines Project, “all that points to the need for some vaccines.”

By partnering with a smaller company called BioNTech, Pfizer got off the grid quickly, and without the money from the US Operation Warp Speed ​​program that funded the trials of other drug companies. This vaccine (like another candidate made by the company Moderna) is actually a custom piece of genetic material called messenger RNA; give it to humans, and the mRNA acts like biological software, teaching cells to produce the “spike” protein on the outer layer of the virus that causes COVID-19. The immune systems of those people then learn to recognize the spike and attack, allowing them to fight the virus. It’s a cool idea, and as my colleague Megan Molteni wrote, it could change the future of vaccinology and infectious diseases.

Cold Case

But this is the first mRNA vaccine and it turns out to be a precious snowflake. Pfizer’s vaccine should be stored and shipped in ultra-cold temperatures, less than 80 degrees below zero — it can be stored for a few days in higher but still very cold conditions. And it needs bottles made of a special glass that can withstand the freezing temperatures. (This is actually neat – the key is that the glass is low in boron, the exact opposite of the famous 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 strike a deal in May to provide it to Pfizer. Whether Corning can make enough is the tricky part.)

All that shipping and freezing requires a level of technical sophistication that, at least for now, is mostly present 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 refrigerated shipment problem. (A pivotal Ebola vaccine needs the same freezer, and engineers came up with the idea of ​​creating specialized coolers to transport it across West Africa — but that was a pandemic that affected tens of thousands of people, not billions, and the people who made the coolers have been out of the cold chain innovation game.)

“Minus 70 is almost a nonstarter”

Those logistical challenges and an overall vaccine shortage will further limit who gets the vaccine first. A Pfizer spokesperson said the company has built its own network of distribution centers, freezers and specialized shipping containers. And meanwhile, Phase I of any vaccination plan will likely involve giving it to health professionals and first responders — the kind of people who will have easier access to where the drug actually is, and may be more likely to come back before the second shot required. the Pfizer vaccine.

“We understand that Pfizer has a network of sites it has partnered with to conduct its clinical trials in the United States,” said Anna Legried Dopp, senior director for clinical guidelines and quality improvement at the American Society of Health-System Pharmacists. Dopp says he understands that there are more than 100 of these locations. “They will be using the ultra-cold freezers they got for the clinical trial,” she says.

This is good; the freezers will be able to change the temperature to accommodate other, future vaccine candidates who need cold, but not if cold, conditions (like, apparently, Moderna’s).

OKAY. So at least one set of weaknesses can also be a strength. So maybe a few others. “We’ll probably figure out how to solve the cold chain in the short term, if only because the economic cost estimates I’ve seen in the US run into the trillions of dollars. Longer term, in the US and globally, anything that has to be minus 70 is almost a non-starter,” said Sam Scarpino, a math epidemiologist at Northeastern University who studies the spread of disease. “We’re going to learn more and more about the vaccine as it scales up from Phase III to injection in 100 million people, and then a billion people — whether it turns out that there are other things we need from a vaccine, and whether there are there are other things in the pipeline.”

Science by press release

What Scarpino means is that the Pfizer vaccine may be good enough to heal the world, but not good enough to do the job. Pfizer has promised a peer-reviewed, detailed accounting of the results, but for now it’s just a press release, and it leaves a lot out. (Getting science through a press release is never ideal.) Pfizer and the FDA withstood extraordinary political pressure to forgo faster data releases that wouldn’t include potential side effects, but the press release said nothing about whether the vaccine demonstrates different levels of protection in different ways. demographic groups (particularly children, adults and the elderly) or have long-term safety concerns.

How could it be? The vaccine is too new and studying vaccine efficacy in subgroups is notoriously difficult. But policymakers will need that data because they will have to decide how to deploy limited supplies. Knowing that one vaccine is better for older people helps tell them where to send it — and vaccines will certainly have different abilities.

By akfire1

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