As the mask-free months tick on, the COVID-19 mRNA vaccine is no longer making itself a headliner in the majority of conversations. There’s no doubt that this vaccine caused a huge amount of controversy, but despite the numerous articles that have made claims about it impacting fertility and altering DNA, none of them have held up under scrutiny.
The vaccine has helped protect millions of people worldwide from COVID-19 infections and hospitalization, but its work is far from over: now, it’s time for scientists to turn their attention back to cancer.
For many years before the world knew anything about COVID-19, mRNA vaccines were already in the process of being developed for cancer treatment. Now, the “success of the mRNA COVID-19 vaccines could help accelerate clinical research on mRNA vaccines to treat cancer.”
How Does an mRNA Vaccine Work?
The ‘m’ in mRNA stands for messenger. The reason that this piece of genetic material was named as such is because it is responsible for teaching our bodies how to make proteins. And proteins play a vital role in fighting disease. To use mRNA for vaccination purposes, it is “encapsulated in a lipid nanoparticle” and injected into the body.
In the COVID-19 case, the mRNA vaccine helps our cells learn how to make copies of the spike proteins that coronaviruses carry so that if we get infected by the real virus at a later stage, our body already knows how to fight it. In terms of treating cancer, the mRNA vaccine is taken up by dendritic cells, which then teach T-cells to kill cancer cells. Scientists are also working on creating mRNA vaccines to treat HIV, malaria, and sickle cell anemia.
In patients with advanced cancer, using the mRNA vaccine in combination with other forms of therapy, such as immune checkpoint inhibitors, is likely to be most effective.
mRNA Vaccines vs. Conventional Vaccines
Four types of cancer vaccines currently exist: tumor/immune cell-based vaccines, peptide-based vaccines, viral vector-based vaccines, and nucleic acid-based (DNA or RNA) vaccines. The reasons that scientists favour the mRNA vaccine above conventional vaccines is because of its safety (it is not made with pathogen particles, so it is non-infectious), efficacy, and cost and time-effective production (they can be rapidly manufactured at a low cost).
Personalized vs. Generalized Vaccines
The fact that cancer presents differently in each individual poses a challenge for vaccine development. But it is a challenge that is already being addressed by the creation of personalized vaccines.
Personalized vaccines can be manufactured for individuals within approximately two months, and they are “based on the specific molecular features” of a person’s tumour.
The Proof is in the Clinical Trials
Results from a clinical trial involving ten head and neck cancer patients who were treated with a personalised mRNA vaccine (in combination with an immune checkpoint inhibitor) showed a complete disappearance of tumours in two participants and a shrinking in the tumours of another five participants.
In another trial involving 13 patients with melanoma, eight remained tumour free two years after receiving personalised mRNA vaccines. A third trial showed that personalised vaccines resulted in a delayed recurrence of pancreatic cancer in 8 out of the 16 patients, and many more clinical trials testing the mRNA vaccine on many different types of cancers are currently underway.
Looking Ahead
mRNA vaccines were first tested on mice in the 1990s. Thanks to the COVID-19 pandemic, they are finally receiving their hard-earned place in the spotlight. With all the funding and resources being filtered towards the development and testing of this technology, hopefully it won’t be too long until mRNA vaccines are readily available to cancer patients across the world!
