TORONTO -- The mRNA technology used for the Pfizer-BioNTech and Moderna vaccines has been hailed as a medical breakthrough in the fight against COVID-19.
The vaccines鈥 high efficacy against SARS-CoV-2, the virus which causes COVID-19, their safety in clinical trials, and how quickly they were produced has generated much excitement within the scientific community.
And while the technology is hardly new 鈥 it鈥檚 been decades in the making 鈥 the pandemic fast-tracked its development thanks to increased interest and funding, and accelerated regulatory approvals.
With the distribution of mRNA COVID-19 vaccines well underway, scientists are already looking ahead to the technology鈥檚 potential to prevent and treat other deadly diseases, such as cancer, malaria, influenza, HIV, Parkinson鈥檚 disease, and the list goes on.
WHY mRNA TECHNOLOGY IS DIFFERENT
Traditional vaccines, such as the seasonal flu shot, work by injecting the patient with weakened or inactivated parts of the actual pathogen or virus, thus exposing their immune system to it. This allows the immune system to create antibodies that can recognize and fight off that same pathogen if it encounters it again.
With mRNA vaccines, on the other hand, there is no actual virus being injected into the individual. Instead, these types of vaccines teach the body鈥檚 cells how to make the necessary antibodies to trigger an immune response.
Messenger ribonucleic acid (mRNA) are genetic instructions that tell the body鈥檚 cells which proteins to make. These proteins are needed for numerous cellular functions inside the body, including for energy and immune defence.
For the COVID-19 vaccines, scientists developed synthetic mRNA in a lab that instructs cells to produce the distinctive spike protein from the SARS-CoV-2 virus. The immune system then targets and destroys these foreign spike proteins. If the body encounters the real virus at a later time, the body鈥檚 immune system will already be prepared to fend it off again.
CANCER, MALARIA, INFLUENZA AND BEYOND
While the mRNA-based vaccines have proven effective at defending against the SARS-CoV-2 spike protein, some scientists are optimistic the technology doesn鈥檛 have to stop there.
In fact, research has already begun to find other applications for mRNA technology to prevent against some of the world鈥檚 deadliest diseases.
CANCER
Dr. Van Karlyle Morris, a gastrointestinal oncologist at the University of Texas MD Anderson Cancer Center, is part of a team of researchers testing mRNA technology for use in preventing the return of colorectal cancer.
For the Phase 2 clinical trials, which have research support from BioNTech, Morris said they鈥檙e using mRNA technology to treat cancer that may still be present in the body.
鈥淲ith COVID vaccines, we鈥檙e trying to prevent something that鈥檚 not there,鈥 he said during a telephone interview with CTVNews.ca on Wednesday. 鈥淚n the context of cancer, we're actually using the mRNA technology to treat something which still may be there.鈥
To do this, the researchers are following high-risk patients with Stage 2 or Stage 3 colorectal cancer who have had a tumour removed. The tissue from the tumour is sent off to a specialized lab where they study the tumour鈥檚 genetic mutations, which is what fuels cancer growth, and identify up to 20 of the most common mutations.
The team then creates a personalized mRNA vaccine based on the tumour鈥檚 specific genetic mutations, which is given to the patient.
鈥淚n treating those patients with an mRNA vaccine that teaches the immune system to go and look for those up to 20 mutations,鈥 Morris said. 鈥淎nd if it can do that, if the immune system can recognize those mutations, it can go find those cancer cells that have those mutations present, and hopefully, kill them and eradicate them.鈥
Because mRNA vaccines are so quick to make, Morris said they can create personalized cancer vaccines that target specific genetic mutations and edit them as they go along.
鈥淭he ability to personalize and the flexibility of the technology to adapt to a given patient鈥檚 specific needs in the setting of cancer or quickly adapt to the needs for infectious diseases, as you鈥檝e seen in COVID-19, I think is something that鈥檚 unprecedented in medicine thus far and it has implications to really transform how we approach all types of medical conditions,鈥 he said.
MALARIA
Dr. Richard Bucala, a professor of medicine, pathology, and epidemiology and public health at the Yale School of Medicine, is also working on a RNA-based vaccine of his own to be used in the fight against malaria.
Malaria, which is the second-leading cause of infectious disease death in the world, is caused by a parasite that is transmitted by mosquitoes when they bite, Bucala said.
The RNA vaccine Bucala and his team are developing would target a specific parasite protein called MIF, which kills the immune system鈥檚 memory cells, thus preventing it from remembering the parasite.
This particular vaccine slightly differs from mRNA vaccines in that it uses self-amplifying RNA (saRNA), which Bucala describes as the 鈥渘ext generation鈥 of RNA vaccines.
Unlike mRNA vaccines, like those developed by Pfizer and Moderna, which require a large amount of mRNA to be injected up front, saRNA only requires a small amount at the beginning because it鈥檚 designed to self-replicate inside the body鈥檚 cells.
鈥淵ou inject it once, and that RNA is replicated for six to eight weeks,鈥 Bucala explained during a telephone interview with CTVNews.ca last week. 鈥淚t makes it much cheaper, much easier to produce, much easier to deliver, especially in the developing world.鈥
This last point is important because Bucala said it鈥檚 very difficult to develop vaccines for developing countries, which is where malaria is most widespread.
While Bucala and his colleagues have been working on this vaccine for years, Bucala said the success of the mRNA vaccines for COVID-19 has made it easier for other research, like his own, to attract interest and funding.
鈥淭he unforeseen benefit of the tragedy of COVID-19 is that RNA now is kind of accepted and opens opportunities for this vaccine approach for other diseases, such as malaria,鈥 Bucala said.
OTHER DEADLY DISEASES
In addition to malaria and cancer, scientists say there is potential for RNA technology to be used in vaccines for the seasonal flu, HIV, Parkinson鈥檚 disease, and multiple sclerosis (MS).
Both Pfizer and Moderna have said they鈥檙e planning to use the technology to develop a vaccine against influenza. that it was developing mRNA vaccine candidates for the seasonal flu, HIV, and the Nipah virus, following the success of its COVID-19 vaccine.
BioNTech, which partnered with Pfizer for the COVID-19 vaccine, how mRNA technology might be used to treat autoimmune diseases, such as MS, in mouse trials.
Morris said for autoimmune diseases, in which the immune system attacks the body, the thinking is that the mRNA could teach the immune system to 鈥渃alm down鈥 or be less reactive against the body鈥檚 cells.
鈥淚t's very, very early, obviously, in this technology, but the potential for this to affect patients with autoimmune diseases as well is I think, you know, extraordinary,鈥 Morris said.
While much of this research has not yet reached the stage of human clinical trials, the hope is that there will be fewer hurdles to get there now that mRNA vaccines have been introduced to the world on a large scale.
Bucala said the emergency circumstances of the COVID-19 pandemic provided an opportunity to try these new vaccines.
鈥淏ecause it鈥檚 trial and error, you don't know that you failed until you鈥檙e at the very end, after human clinical trials. And now with the RNA technology, which is less expensive and easier, and regulatory agencies being more on board, I think it opens business opportunities,鈥 Bucala said. 鈥淚t鈥檚 very much a good news story.鈥
