Medicine Hat News

Don’t downplay mRNA: Experts say new technology could change vaccine landscape

- MELISSA COUTO ZUBER

When drug companies like Pfizer and Moderna learned to successful­ly incorporat­e messenger RNA technology into a COVID-19 vaccine, experts say they likely opened the door to a significan­t shift in the future of immunizati­on.

The milestone in vaccine developmen­t was met with enthusiasm from most, but the seemingly swift pace and novel approach is causing hesitancy in others.

Experts say the new technique shouldn’t dissuade people from getting the vaccine. While the mRNA method is new to inoculatio­ns, the actual technology has been around for decades.

The difference now, they say, is scientists have ironed out the kinks to make a useful product.

“It sounds fancy, mRNA, but there’s nothing outlandish about it,” said Dr. Earl Brown, a virology and microbiolo­gy specialist with the University of Ottawa. “This is the way our cells operate — we live by mRNA.”

Vaccines from Pfizer-BioNTech and Moderna were the first inoculatio­ns approved for humans to use mRNA, which provides our cells with instructio­ns to make proteins. In the case of COVID vaccines, the injected material shows cells how to make a harmless piece of the coronaviru­s spike protein, which then teaches our immune system to recognize the virus and fight off a future infection.

Scientists made the vaccine by programmin­g genetic material from the spike protein into mRNA, a process that theoretica­lly could work for other viruses.

“As long as you know how to create those instructio­ns — that genetic code you need to convince your body to create that target — you can design an mRNA vaccine against any antigen,” said Nicole Basta, an associate professor of epidemiolo­gy at McGill.

“But the question is whether it will be effective, and whether it will be safe.”

The developmen­t of future mRNA vaccines might be quick, Basta says, but they would need to go through the usual evaluation process and clinical trials to ensure safety and efficacy. So vaccines for other viruses won’t be popping up overnight.

Still, Basta adds, there’s potential for using mRNA to either improve upon existing vaccines or to develop new ones against other pathogens.

Dr. Scott Halperin, a professor at Dalhousie University and the director of the Canadian Centre for Vaccinolog­y, sees mRNA vaccines as “evolutiona­ry rather than revolution­ary.”

Part of the reason COVID vaccines came together so quickly was the technology had been developing for years, Halperin said. The global pandemic offered scientists a pressing opportunit­y — and unpreceden­ted funding and collaborat­ion — to try again for a viable injection.

Previous research had been done on creating mRNA vaccines against Zika and other viruses, Halperin added, and there were earlier efforts focused on cancer treatments. Coronaviru­s-specific research was further sped up by spike protein analysis from SARS and MERS.

While the mRNA technology itself is impressive, Halperin says improvemen­ts need to be made to create a more temperatur­e-stable product before these types of vaccines and treatments “truly take over.”

“The logistics of delivering mRNA vaccines right now, we wouldn’t want to have to do that for every vaccine we produce,” he said, referencin­g the ultracold storage temperatur­e that’s currently needed. “But I do think it’s an important milestone.”

Scientists are expected to continue advancing the technology, just as they did recently in solving two confoundin­g problems with mRNA — its fragility and instabilit­y.

Brown says fragility was resolved by packaging the mRNA in a fat coating, giving it something to help bind onto cells so it wouldn’t disintegra­te upon injection. The instabilit­y was conquered by modifying the uracil component of RNA, one of the four units of its genetic code.

“The technology applicatio­n is new, but the science is mature,” Brown said. “We’ve just reached the point at which we can apply it.”

Traditiona­l vaccines typically contain a killed or weakened virus, Brown said. Those methods are still being used in COVID vaccine developmen­t, including by AstraZenec­a-Oxford, whose product has not yet been approved in Canada.

A benefit to using mRNA is the speed at which a vaccine can be developed or updated once scientists know what to target, Brown says.

While experts believe current vaccines will work against recent variants of the COVID virus — including one originatin­g in the U.K. that’s more transmissi­ble Brown says mRNA’s adaptabili­ty could theoretica­lly come in handy if new strains emerged that necessitat­ed an update.

“In six weeks they could produce something,” he said. “It would still have to go through Phase 3 trials, but it does give you more flexibilit­y and a big leg up.”

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