Never before have we managed to build an arsenal to beat back a life form entirely novel to us, massively accelerating vaccine development by months, if not years-a true paradigm shift not just in vaccinology, but also in how science is done and communicated under fire.
Last week, the FDA and its Canadian and British equivalents approved the Pfizer-BioNTech mRNA vaccine for emergency use.
Moderna’s mRNA vaccine is hot on its heels, also boasting a success rate of over 90 percent.
There’s good reason to look ahead-the biotech and camaraderie that created an entirely new type of vaccine in record pace isn’t confined to the pandemic, vaccine research, or infectious diseases.
You might have heard that mRNA vaccines have never previously been approved by the FDA. Yet the science behind them is decades long, courtesy of a young Hungarian-born biologist behind a key mRNA discovery-one so novel and groundbreaking it precipitated the death of her career.
mRNA, short for messenger RNA, is the translator that literally moves between our cells’ DNA library and the protein factory.
In other words, our bodies listen to mRNA to decide which proteins to build.
If we could design and synthesize artificial mRNA and deliver them into cells, it’s possible in theory to hijack our cells’ own protein-building system to make any protein we want-even those that are foreign, such as viral proteins.
By delivering the mRNA of a viral part into our cells, our bodies will make these proteins.
There’s a reason mRNA vaccines are so desirable.
Compared to traditional protein-based ones, such as those involving dead viruses that need to be grown in chicken embryos, mRNA is incredibly easy to scale in production with low costs. Thanks to recent advances in biotech and Covid-19, mRNA drugs have finally become a widely successful reality.
Broadly speaking, three main technologies have propelled mRNA vaccines to success in the Covid-19 race: whole-genome reading, mRNA design and packaging, and mRNA synthesis.
In early February, long before the world realized we’d be in the midst of a pandemic, scientists had already nailed down the sequence and shape of the protein that eventually spurred the development of our newfangled mRNA vaccines.
The harder part was designing mRNA candidates, the “Instructions,” to encode for the spike protein. One frustrating reason why mRNA vaccines have previously failed is because these molecules are extremely fragile.
With hopes of making mRNA drugs a reality, scientists have long worked to change their basic components-“Letters” very similar to DNA’s familiar quad squad of A, T, C, and G-with slightly chemically-improved ones to increase their stability.
Other swaps fine-tune the mRNA’s efficacy so that it triggers a Goldilocks-like immune response-not too much, not too little. Finally, naked mRNA needs to get inside a cell to work. Without mRNA sticking around, our bodies can’t make the viral spike protein, hence no immunity.
To deliver it into cells, scientists relied on fatty bubbles-also known as lipid nanoparticles-to form a vessel around the mRNA strands.
Pfizer-BioNTech and Moderna’s results provide some of the strongest evidence that they also work well with mRNAs. The biotechnologies that made Covid-19 mRNA vaccines are here to stay.
From the ins and outs of immune responses to what makes mRNA more stable, less toxic, and easier to deliver, to advances in synthetic biology and seamless global collaboration, the battle against Covid-19 highlights how a decade-long scientific dream just blossomed to fruition.
mRNA is the body’s “Guidebook” for building protein-any protein.
A synthetic mRNA strand that recognizes certain types of cancer could lead to highly-specific “Cancer vaccines.” BioNTech, for example, reported in 2017 that a vaccine against melanoma, tailor-made to each of its 13 participants’ unique cancer genetic profile, had higher immunity against their tumors and reduced the chance of spread. Synthetic mRNA could artificially produce missing or defective proteins in the body, such as those critical for normal eyesight or nerve function. The dream of mRNA therapeutics has been alive since the 90s. One just came true.