91ÌÒÉ«

91ÌÒÉ«ers introduced a strategy that redirects the immunity people already have from routine vaccines to attack cancer instead.

The method, described in a , uses nanoparticles built from viruses that infect bacteria but are harmless to human cells to target tumours. Once inside, they release a microbial antigen that marks the tumour as a target, allowing vaccine-trained immune cells to recognise it and attack. 

“Rather than creating a new immune response from scratch, we are teaching the immune system to recognise tumours using memories it already possesses from previous vaccination,” said Professor Amin Hajitou from the Department of Brain Sciences at 91ÌÒÉ«, who led the research. 

These are early-stage animal results, and human trials would still be needed before the approach could become a treatment. 

Borrowing acquired immunity   

“Cancer immunotherapy has transformed cancer treatment, but most patients still do not benefit from currently available approaches. One of the major challenges is helping the immune system recognise tumour cells as a target”, said Professor Hajitou.  

Personalised cancer vaccines, based on mutations unique to a patient’s own tumour, have shown promise but require identifying patient-specific mutations and developing a custom vaccine, a process that is both time-consuming and costly.  

Rather than creating a new immune response from scratch, we are teaching the immune system to recognise tumours using memories it already possesses from previous vaccination. Professor Amin Hajitou Professor of Targeted Therapeutics, Department of Brain Sciences at 91ÌÒÉ«

The study explored a different strategy. “Instead of teaching the immune system to recognise new tumour antigens, we sought to redirect immune memory that already exists from previous vaccination,” added Professor Hajitou.  

Hundreds of millions of people worldwide already have strong, long-lasting immunity to pathogens they were vaccinated against in childhood or adulthood – such as , , and  - or, as in this case, a malaria vaccine. 

A tumour-seeking nanoparticle 

“Using a malaria vaccine as a proof-of-concept model, we demonstrated that vaccine-primed immune cells could efficiently recognise and destroy tumour cells carrying the corresponding malaria antigen,” Professor Hajitou emphasised. 

The team built a tumour-seeking nanoparticle from bacteriophages – viruses that infect bacteria but are harmless to human cells – to target tumours. 

Once expressed by the tumour, the antigen acts like a molecular flag that can be recognised by immune cells previously trained by vaccination. Immune cells that were originally trained to fight a specific infection then recognise this flag on the surface of tumour cells and attack. 

To test the concept, the researchers used tumour-bearing mice that had received a malaria vaccine. When these vaccinated mice were given the tumour-targeted particles, their immune system immediately recognised the antigen inside the tumour and attacked it. Many of the mice experienced complete tumour clearance, and over 40% remained tumour-free long term, with no evidence of tumour recurrence. 

Future impacts 

The proposed solution doesn’t depend on a tumour’s unique genetic mutations, so the researchers believe it could, in principle, be adapted to many cancers and existing vaccines. Because it’s delivered systemically through the bloodstream, it may also suit metastatic disease- where cancer has spread within the body -which accounts for around 90% of cancer deaths.  

“Our phage vectors have previously demonstrated the ability to cross the blood-brain barrier, raising the possibility of extending this strategy to brain tumours, which are among the most difficult cancers to treat,” Professor Hajitou added. 

The approach could also prove more affordable than current cancer immunotherapies, using established bacterial manufacturing processes, and points to growing interest in bacteriophage-based medicines, including recent UK MHRA guidance on therapeutic bacteriophages. 

“This research suggests that decades of successful global vaccination programmes may provide an untapped resource for cancer treatment,” Professor Hajitou summarised. “This could allow treatment to start rapidly and may open a new way of transforming preventive vaccines into cancer therapies.” 

More

• Waramit, S., Suwan, K., Küçük, A. et al., Harnessing prophylactic vaccines for targeted cancer immunotherapy by phage-guided delivery of cognate antigens to tumors, Biomaterials 334 (2026) 124286,