Pfizer Covid-19 vaccine a miracle for genetic medicine

“Look me in the eyes,” the doctor ordered, staring at me from behind her plastic face guard. Her eyes were blue, almost as blue as her hospital mask. Yet, after a moment, I started to turn and face the doctor on my left, who was jabbing a long needle deep into the muscle of my upper arm. “No!” the first doctor snapped. “Look at me!”

Then she explained. Because I was part of a double-blind clinical trial of an experimental covid-19 vaccine, they had to make sure that I didn’t get any clues about whether I was being injected with a real dose or merely a placebo made of saline solution.

It was early August, and I had enlisted in the clinical trial for the vaccine that has just reported very promising results: the one developed by Pfizer with the German company BioNTech. It is a new type of RNA vaccine that has never before been deployed.

Vaccines work by stimulating a person’s immune system. One traditional approach is to inject a weakened version of the dangerous virus. That’s the way we now fend off measles, mumps, rubella and chickenpox. Another method is to use a version of the virus or a part of the virus that has been totally killed.

The success of the Pfizer vaccine means that the plague year of 2020 will be remembered as the time when traditional vaccines began to be supplanted by genetic vaccines. Instead of delivering tiny and safe doses of the virus itself, these new vaccines deliver a piece of genetic coding that will instruct human cells to produce, on their own, components of a targeted virus. These safe components can then stimulate the patient’s immune system.

It is another wondrous miracle from a biotech revolution in which knowledge of genetic coding will become as important as digital coding and molecules will become the new microchips.

Carrying genetic instructions

I enrolled in the trial at Ochsner Hospital in my hometown of New Orleans partly to be a good citizen but also because I’m writing a book about the gene-editing tool known as CRISPR, and the star molecule in the book is RNA. The vaccine that was developed by Pfizer and BioNTech makes use of the most basic functions that RNA performs: serving as a messenger RNA (mRNA) that carries genetic instructions from DNA, which is bunkered inside a cell’s nucleus, to the manufacturing region of the cell, where it directs what protein to make. In the case of the covid-19 vaccine, the mRNA instructs cells to make a version of the spike protein that is on the surface of a coronavirus. That spike protein can then stimulate our immune system to create antibodies that will protect against the real coronavirus. In addition to the Pfizer version, the Cambridge, Mass.-based company Moderna is also making an mRNA vaccine.

When I volunteered, I was told that the study could last two years. That raised a few questions. What would happen, I asked the coordinator, if the vaccine got approved before then? She told me that I would then be “unblinded,” meaning that they would tell me if I had gotten the placebo and, if so, immediately give me the real vaccine.

What would happen if some other company’s vaccine got approved while our trial was still underway? “That’s not been decided,” she conceded.

So, I went to the top. I posed these questions to Francis Collins, director of the National Institutes of Health, which is funding and overseeing the vaccine studies. “You have asked a question that is currently engaging the members of the Vaccines Working Group in serious debate,” he replied. Just a few days earlier, a “consultation report” on this issue had been prepared by the Department of Bioethics at NIH. Even before reading the report, I was impressed and comforted that NIH had something called a Department of Bioethics.

Trial of a vaccine

The report was thoughtful. If you’re in a trial of a vaccine that gets FDA approval, you will immediately be given the real vaccine if you were in the placebo group. If you’re in one trial and another company’s vaccine gets approval, the new vaccine will be offered to those who were in the placebo group.

That’s why it’s a good idea to volunteer for clinical trials.

The great news about RNA vaccines is that they can easily be reprogrammed. Even after we defeat covid-19, new viruses will come along. When that happens, it will take only days to code a new RNA sequence to make a vaccine to target the new threat. Tools made with RNA will enable us both to edit our genetic material and to devise easily reprogrammable vaccines.

It’s been a miserable pandemic amid an annus horribilus. It’s nice that both appear to be ending with RNA — the fundamental molecule that probably spawned the existence of life on our planet a few billion years ago — giving birth to a new era of biotechnology.

Walter Isaacson, a professor at Tulane, is the author of “The Code Breaker: Jennifer Doudna, Gene Editing, and the Future of the Human Race,” to be published in March.

Washington Post