Study suggests mRNA COVID-19 vaccines can improve chances of cancer survival
COVID-19 vaccines could prolong the life of cancer patients by activating a powerful immune response that boosts the effectiveness of immunotherapy.
- 31 October 2025
- 4 min read
- by Priya Joi
COVID-19 mRNA vaccines that saved millions of lives worldwide during the pandemic also doubled cancer survival rates, according to a new study published in Nature.
The researchers ascribe this to the fact that mRNA vaccines can ‘wake up’ the immune system, thus boosting the effectiveness of cancer treatment.
Collateral benefits
The research team knew that a type of immune cell called type-1 interferon can ramp up the immune response.
Earlier this year, one of the co-authors Elias Sayour, University of Florida and colleagues, also publishing in Nature, published the first data showing that mRNA vaccines – that are known to ramp up type-I interferon activity – could rev up the body’s defences to make tumours more susceptible to treatment.
The team hypothesised that mRNA vaccines designed to target the SARS-CoV-2 virus might also have collateral benefits in antitumour effects.
The vaccinated group had a 3-year overall survival rate of 55.7%, compared with 30.8% in the unvaccinated group – this translates into a 49% reduction in cancer-associated mortality risk.
In their paper published this month, Steven Lin at The University of Texas MD Anderson Cancer Center, Houston, along with Sayour and other colleagues, combined retrospective analysis of pandemic cancer survival with animal studies of the mechanism of action.
They retrospectively looked at cancer survival in over 1,000 patients who had received immunotherapy and who had also been given COVID-19 mRNA vaccines.
Their hopes were confirmed: patients who received an mRNA-based COVID-19 vaccine within 100 days of starting immunotherapy were more than twice as likely to be alive after three years compared with those who didn’t receive either vaccine.
The vaccinated group had a 3-year overall survival rate of 55.7%, compared with 30.8% in the unvaccinated group – this translates into a 49% reduction in cancer-associated mortality risk.
The cancer patients had been receiving a revolutionary anti-cancer treatment called immune checkpoint inhibitors (ICIs) that harness the body's immune system to fight tumours.
Cancer tumours can hide from the immune system by switching off the body’s ‘checkpoint proteins’ that prevent the immune system from attacking healthy cells and flagging dangerous cells.
Checkpoint inhibitors enable immune cells, such as T cells, to recognise and eliminate cancer cells more effectively. However, even this advanced therapy only works for a fraction of patients.
Some tumours remain resistant to immunotherapy because there’s no damage report by the immune system – i.e. the body doesn’t see the tumours as abnormal cells and therefore doesn’t raise an alert.
Jumpstarting the immune system with mRNA vaccines restores this damage response, says Dr Sayour, allowing the body to attack the tumour more effectively.
Investigating the mechanism
Intrigued, they investigated the mechanism of this action in mouse models.
The animal studies showed that COVID-19 vaccines trigger a surge of type-I interferons, particularly one called called interferon alpha. This interferon surge, in turn, activates the body's innate immune system, priming T-cells to recognise and attack tumour-associated antigens.
While this T-cell spike prompts the tumours to increase the expression of a molecule that acts as a brake on the immune system, this is neutralised by the immune checkpoint inhibitor therapy, which allows the body to continue to fight the cancer.
In an op-ed in The Conversation, two of the authors – Adam Grippin of the University of Texas MD Anderson Cancer Center and Christiano Marconi of the University of Florida – explained that: “We found that COVID-19 mRNA vaccines act like an alarm, triggering the body’s immune system to recognize and kill tumor cells and overcome the cancer’s ability to turn off immune cells.
“When combined, vaccines and immune checkpoint inhibitors coordinate to unleash the full power of the immune system to kill cancer cells.”
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Equity in cancer treatment
The researchers are hopeful that this finding will widen access to lifesaving cancer treatments. While personalised medicine could soon offer unique mRNA vaccines for cancer patients, these will be expensive and hard to make.
Now, the team are preparing to test COVID-19 mRNA vaccines along with immune checkpoint inhibitor treatment in a nationwide randomised clinical trial in lung cancer patients.
This study will indicate whether these vaccines should be included as part of the treatment approach for patients receiving an immune checkpoint inhibitor.
Speaking to VaccinesWork, Dr Sayour said “If these results are confirmed in a randomised phase III trial (which we are actively planning and expect to move forward before the end of the year), we believe it could revolutionise the field and help patients across the globe access a widely available low-cost alternative.”
