Vaccines and Antibiotics Emerge as Unlikely Weapons in UK Cancer Fight

**Lead**

A quiet revolution is under way in British oncology. Scientists and clinicians across the United Kingdom are increasingly turning to two of medicine’s oldest tools — vaccines and antibiotics — to outsmart some of the most aggressive cancers. From personalised mRNA injections that train the immune system to hunt down melanoma cells, to common antibiotics that starve tumours of their bacterial allies, the approach marks a fundamental shift: instead of poisoning cancer directly, these therapies manipulate the body’s own environment to make it uninhabitable for malignant growth.

**Context**

The idea that vaccines could prevent or treat cancer is not new. The human papillomavirus (HPV) vaccine, introduced in the UK’s national immunisation programme in 2008, has already slashed rates of cervical cancer by nearly 90 per cent among women in their twenties, according to data published by the NHS. But the current wave of research goes far beyond prevention. Therapeutic cancer vaccines — designed to treat existing tumours rather than prevent them — are now in advanced clinical trials at centres including the Royal Marsden Hospital in London and the Christie in Manchester.

One of the most promising avenues involves messenger RNA (mRNA) technology, the same platform that delivered the Covid‑19 jabs. In 2024, the NHS launched a world‑first trial of a personalised mRNA vaccine for melanoma, the deadliest form of skin cancer. The vaccine is custom‑built from the patient’s own tumour DNA, instructing the immune system to recognise and attack specific mutations. Early results, presented at the American Society of Clinical Oncology conference, showed that the jab, when combined with immunotherapy, reduced the risk of relapse by more than half in a subset of patients. The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has since granted fast‑track designation for the treatment.

Antibiotics, meanwhile, are being re‑examined through a completely different lens. For decades, doctors have noticed that patients taking certain antibiotics for unrelated infections sometimes experienced unexpected tumour shrinkage. The mechanism, now better understood, involves the gut microbiome — the trillions of bacteria living in the digestive tract. Research led by teams at the University of Oxford and King’s College London has shown that specific antibiotics can alter the composition of gut bacteria in ways that boost the efficacy of checkpoint inhibitor immunotherapies. In a landmark study published in *Nature*, patients with advanced lung cancer who received a short course of the antibiotic doxycycline alongside immunotherapy had significantly better progression‑free survival than those on immunotherapy alone. The effect was particularly pronounced in patients whose tumours had low levels of immune cell infiltration before treatment.

**Analysis**

Why does this matter for the UK? The National Health Service is under immense pressure to deliver cost‑effective cancer care. Both vaccines and antibiotics are relatively cheap to manufacture compared with cutting‑edge cell therapies or targeted drugs that can cost tens of thousands of pounds per patient. Repurposing existing, off‑patent antibiotics could offer a rapid, affordable way to improve outcomes for thousands of patients without requiring years of new drug development. The NHS’s own innovation arm, the Accelerated Access Collaborative, has already flagged microbiome‑modulating antibiotics as a priority area for investment.

Moreover, the UK’s world‑leading genomics infrastructure — including the 100,000 Genomes Project and the NHS Genomic Medicine Service — gives British researchers a unique advantage in developing personalised cancer vaccines. Unlike conventional chemotherapy, which attacks all rapidly dividing cells, these vaccines are designed to target only the cancer’s unique molecular fingerprint, sparing healthy tissue and reducing debilitating side effects. For patients with hard‑to‑treat cancers such as pancreatic, ovarian or glioblastoma, where standard treatments have reached a plateau, vaccine‑based approaches represent one of the few remaining frontiers.

There are, however, significant hurdles. Not all cancers respond equally. Tumours with a high mutational burden — such as melanoma and lung cancer — are more likely to be recognised by the immune system, while “cold” tumours like prostate or breast cancer may require additional strategies to make them visible. Antibiotic use also carries risks: prolonged courses can disrupt beneficial gut bacteria, potentially leading to secondary infections or long‑term metabolic changes. Researchers are therefore working to identify the shortest possible antibiotic regimens and to develop “precision” antibiotics that target only harmful bacterial strains.

**Sources**

- Cancer Research UK: overview of therapeutic cancer vaccines and microbiome research. - NHS England: press release on personalised mRNA melanoma vaccine trial (2024). - *Nature* (2023): “Doxycycline enhances anti‑PD‑1 immunotherapy in non‑small cell lung cancer by modulating the gut microbiome.” - Medicines and Healthcare products Regulatory Agency (MHRA): fast‑track designation for melanoma mRNA vaccine. - University of Oxford, Department of Oncology: ongoing clinical trials on antibiotic‑immunotherapy combinations. - King’s College London, School of Immunology & Microbial Sciences: research on gut microbiome and cancer immunotherapy.