Covid vaccines may increase the lifespan of cancer patients – this could be a game changer | Devi Sridhar

IWe are often asked if we are better prepared for the next pandemic. The response is mixed, but the positive is the scientific advances in vaccines. The Covid vaccines were produced faster than any previous effort and are credited with saving millions of lives starting in 2021. The mRNA vaccines – Pfizer/BioNTech and Moderna – were designed within days of the publication of the Sars-CoV-2 genome in January 2020, and underwent safety trials over the following months before finally being approved in the UK in late 2020.

But could they have additional benefits? According to a recent study published in Nature, mRNA vaccines appear to trigger a powerful immune response that increases median survival time by about 75% for some cancer patients. These results – which are under development – ​​could indicate the value of repurposing vaccines and drugs that have already passed safety trials and are available at a reasonable cost.

How could Covid vaccines play a role in cancer treatment? Cancer develops when normal cells in the body grow and divide out of control. Usually, cell division is strictly controlled, but when certain mutations occur – sometimes caused by smoking, radiation, inherited genetic factors, or environmental exposure – the body is no longer able to stop uncontrolled cell growth. These cells (often called malignant) accumulate to form a tumor – an abnormal growth. To continue growing, these cells create new blood vessels to feed themselves and begin to spread throughout the body – called metastasis.

Our immune system is excellent at recognizing invaders in our body – think viruses or bacteria – but because cancer cells are part of our body, it proves difficult for our immune system to distinguish them from healthy cells. When treating cancer, doctors have several options. Surgery or radiotherapy is usually the start, to simply eliminate or target localized cancer cells. If they have spread throughout the body, then chemotherapy is necessary: ​​this essentially involves “neutralizing” the body to kill the cancer cells. Chemotherapy drugs target rapidly dividing cells to stop the growth of tumors, but this means they also kill healthy cells in hair follicles, stomach lining and bone marrow. It is a brutal and barbaric intervention.

Immunotherapy is a more targeted approach: its goal is to prime the immune system to attack only cancer cells. Most research efforts have focused on developing vaccines and targeted drugs for specific cancers, which involves a lengthy and expensive process of testing for safety, efficacy, and dosing. But what appears to be happening with mRNA vaccines is different: They appear to activate the immune system in general, which helps the body fight cancer cells.

US researchers reviewed the medical records of patients with stage 3 and 4 lung cancer treated between 2015 and 2022 at the University of Texas MD Anderson Cancer Center. Of these, 180 patients had received a Covid mRNA vaccine – Pfizer or Moderna – within 100 days of starting immunotherapy treatment. In this observational study, researchers compared them to 704 patients who were taking the same medications but had not received the Covid vaccine.

After controlling for age, disease severity and other confounding factors, the results were striking: Vaccinated patients lived a median of 37.3 months, compared to 20.6 months in the unvaccinated group. Three years after the start of treatment, 55.7% of vaccinated patients were alive, compared to 30.8% of those who were not. A similar trend was seen when looking at a second group of patients with metastatic melanoma (a skin cancer that has spread throughout the body). The same benefit was seen whether it was Pfizer or Moderna, but not in the non-mRNA Covid vaccines.

The gains are significant and well beyond the norm for most cancer drugs. A study examining the clinical impact of 124 new cancer drugs approved by the US FDA between 2003 and 2021 found that, on average, the new drugs only increased median overall survival by 2.8 months.

To explore these findings further, scientists studied the impact of mRNA vaccines in mice. They discovered that combining an mRNA vaccine with immunotherapy could activate the immune system and transform previously hidden (“cold”) tumors into recognizable tumors.

What could explain this? Researchers suggest that mRNA vaccines act as a surge, activating immune cells throughout the body. This does not directly target the cancer, but triggers the immune system to be more alert and responsive.

If these results are confirmed by other studies, it could revolutionize the way cancer is treated. As Dr. Elias Sayour, an oncologist and co-author of the study, said: “We could design an even better non-specific vaccine to mobilize and reset the immune response, in a way that could essentially be a universal, commercially available cancer vaccine for all patients.” » Given that Covid mRNA vaccines have already been tested for safety in millions of people, researchers see the potential for repurposing them as an inexpensive, low-risk way to boost the immune system alongside traditional cancer treatments.

But there are caveats. The findings come from an observational study – that is, a review of patients’ medical records, rather than a study designed from the ground up to test this effect – meaning it can show an association, not causation. Randomized controlled trials (or RCTs) are needed to confirm whether it is indeed the vaccine that makes the difference. Animal studies are also needed to further examine the exact biological mechanism beyond just general activation of the immune system.

But just imagine having more precise and effective cancer treatments, without the harsh consequences and side effects of chemotherapy. I remember my father suffering through rounds after rounds of chemotherapy and wondering if the cure was worse than the disease. The Nature study reminds us that science often progresses in surprising ways. Covid mRNA vaccines may not only have saved lives during the pandemic, but they could also save lives from cancer.

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