Pfizer and Moderna Could Mark the Start of a New Era in Vaccines

If approved, the companies’ Covid-19 vaccines would be the first of their kind

Photo: JOEL SAGET/AFP/Getty Images

Last week, drugmaker Pfizer and German biotech partner BioNtech announced that their Covid-19 vaccine was more than 90% effective in a clinical trial, sparking hope that an end to the pandemic may soon be achievable. More good news came this week, with an announcement from Massachusetts-based biotech firm Moderna that its vaccine was 94.5% effective. Not to be outdone, Pfizer released more data on Wednesday, showing 95% efficacy.

Stocks of the companies soared on the news. Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, called the results “very impressive” and said 20 million Americans could be vaccinated against the coronavirus by the end of December or beginning of January. If the Food and Drug Administration authorizes their use, they would be the first vaccines of their kind on the market.

Vaccines usually take a decade or more to develop. Getting a Covid-19 vaccine to the public in less than a year would be nothing short of a scientific triumph. In addition, Pfizer and Moderna’s vaccines, which are made using genetic technology that has never been approved for human use before, give us a glimpse of how vaccines could be developed in the future when new infectious diseases emerge.

The traditional method for making and mass-producing vaccines is complicated, expensive, and extremely time-consuming. It involves first growing a virus or other pathogen in animal cells or chicken eggs, which can take months. Then, the pathogen is extracted and killed or weakened so it doesn’t cause infection (some newer vaccines use just a small piece of the pathogen). Then, the vaccine has to be purified and must undergo extensive safety testing.

Pfizer and Moderna’s vaccines rely on a different approach. Instead of using the actual pathogen or part of it to spur an immune response, they use a small sequence of genetic code, known as messenger RNA (mRNA). The genetic material delivers a set of instructions that tells the body to temporarily make a protein that resembles one on SARS-CoV-2, the virus that causes Covid-19. The body then recognizes the protein as foreign and ramps up an immune response, generating protective antibodies. A handful of other companies, like Inovio Pharmaceuticals and Novavax, are using DNA instead of mRNA in their vaccines, but they work on the same principle.

One of the benefits of this approach is that it doesn’t require growing the actual pathogen. All that’s needed is its genetic blueprint. Thanks to recent advances in genome sequencing technology, generating that blueprint is faster and cheaper than ever before. In January, soon after China reported a mysterious cluster of pneumonia cases, Chinese researchers posted the draft genome sequence of the novel coronavirus online. That allowed companies like Moderna and BioNTech to quickly get to work on a vaccine. Researchers immediately zeroed in on the virus’s spike protein, which they knew from studying other coronaviruses like MERS and SARS allows the virus to gain entry into human cells.

“In a matter of a week, if you know what the pathogen is, you can make the RNA and start testing the vaccine.”

Next, Moderna and BioNTech manufactured tiny pieces of synthetic mRNA that code for the spike protein. Within weeks after Chinese researchers made the SARS-CoV-2 genome public, Moderna shipped its first doses of experimental vaccine to the National Institutes of Health for testing.

“These vaccines can be made very quickly,” Drew Weissman, MD, PhD, an expert on RNA vaccines at the University of Pennsylvania, told Future Human. His lab originally developed the technology Moderna is using. “In a matter of a week, if you know what the pathogen is, you can make the RNA and start testing the vaccine.”

As I wrote in August, the idea of these so-called genetic vaccines arose nearly 30 years ago, and scientists have been working to refine them ever since. The field has had its ups and downs, and some of the early vaccines didn’t pan out. With Pfizer and Moderna’s positive results, more researchers could pursue vaccines based on this technology.

The promise of these vaccines is their adaptability. All it would take is swapping out the piece of genetic material when a new virus comes along. Scientists who are genetic vaccine evangelists see the technology as a “plug-and-play” platform. Margaret Liu, MD, chair of the board of the International Society of Vaccines and an early pioneer of genetic vaccines, likens the process to making different flavors of ice cream once you learn the basic recipe.

Plus, DNA and RNA are cheaper to produce than the components of traditional vaccines, and only small quantities of it are needed to make genetic vaccines. That could allow companies to ramp up manufacturing more quickly than existing vaccines.

It will still take months of monitoring people who got Pfizer and Moderna’s vaccines to learn just how effective they are and how long their protection lasts. But if they’re successful, they could not only help end the current pandemic but also usher in a new era of vaccine development. Instead of taking years and decades to make new vaccines, the timeline could be shortened to months. That way, we could be more prepared when the next infectious disease threat comes along.

“It may actually change how other vaccines are produced,” Rahul Gupta, MD, senior vice president and chief medical and health officer at the March of Dimes, told reporters during a National Press Foundation briefing in August. “We may be at the cusp of very much a new technology.”

Former staff writer at Medium, where I covered biotech, genetics, and Covid-19 for OneZero, Future Human, Elemental, and the Coronavirus Blog.

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