20 April 2026
Professor Angus Dalgleish has told the All-Party Parliamentary Group on Pandemic Response and Recovery that his early 2022 observations of a link between mRNA COVID booster vaccines and increased cancer relapses and aggressive new tumours have now been independently replicated by researchers across the world.
The distinguished medic is one of the UK’s leading melanoma specialists and a pioneer of cancer immunotherapy who developed some of the first immunotherapy treatments for melanoma. Uniquely for the NHS he has served as a consultant in virology, immunology and oncology. He first raised the alarm after six of his long-term stable stage-4 melanoma patients relapsed within six weeks in late 2021/early 2022, all shortly after receiving a booster dose.
Professor Dalgleish said: “The only common factor we could find was the booster. These patients had been stable for three to 18 years. The relapses required new treatment. We conducted laboratory testing which showed the booster, and I must emphasise that it is the booster or third dose onwards, not the original two doses which rarely produce detectable signals, that changed everything. We observed that following the booster, profound T-cell exhaustion and suppression occurred, the very immune mechanism that keeps melanoma and other cancers in check. Together with colleagues, we wrote several open letters to the Medicines and Heathcare products Regulatory Agency (MHRA) as early as 2021 to raise concerns. Replies, if we got them, made it clear that they were not taking our concerns seriously.”
What began as an observation in melanoma rapidly broadened. A North East colorectal surgeon, Mr James Royle, reported a complete reversal in his practice: tumours that were once mostly early-stage in patients in their 60s and 70s became predominantly late-stage (3 and 4), highly aggressive and appearing in people in their 20s and 30s, with marked clotting and inflammation.
Chronic inflammation and micro-clotting are both known drivers of the spread of certain cancers, including colon, pancreatic and prostate cancers. These effects are also associated with mRNA boosters (Pfizer and Moderna), which comprised most of the boosters administered. The viral-vector AstraZeneca vaccine was already being phased out before widespread booster use, prior to withdrawal by its manufacturer in 2024. So while its spike protein can still promote clotting-related pathology, it was less implicated.
Professor Dalgleish added: “We have seen similar patterns emerge globally and a number of studies have made it plain, such as the major Spanish multi-hospital study Evidence of exhausted lymphocytes after the third anti-SARS-CoV-2 vaccine dose in cancer patients. Analyses of population data in Japan, South Korea and Italy, have shown cancer incidence rising sharply and linearly after the third, fourth and fifth mRNA doses, affecting not only melanoma and colorectal cancer but a broad-spectrum including breast, pancreas, gallbladder, glioma and others. Instead of the drug regulators doing their jobs in response, the studies have been ignored or faced intense attempts at retraction and interference.”
APPG Chair, Esther McVey, commented: “Our Group has heard some shocking evidence over the years but I am genuinely taken aback hearing Professor Dalgleish’s stark message: long-stable cancer patients appear to be relapsing aggressively after mRNA boosters. His clinical observations seem to be supported by independent international studies. The apparently linear progression, where the more boosters a person has the greater the risk, is extremely worrying.”
Professor Dalgleish explained further that his observations of T-cell exhaustion after the third dose, impairing immune surveillance, meant that the mRNA vaccines were effectively teaching the body to accept cancerous tumours, as it would a transplanted organ. He described it as a class-switch of antibodies from neutralising to tolerising, with persistent mRNA integration into host DNA at random sites activating oncogenes, genes that can switch on and cause cancer, and disabling tumour-suppressor genes. An additional factor is the reported contamination in the Pfizer vaccines with fragments of the SV40 promoter, a known oncogene used in laboratories to promote cancer in mice for clinical trials.
APPG co-chair Graham Stringer said: “Professor Dalgleish, with his extensive scientific and medical background, is uniquely suited to understand the clinical signals. His concerns surely warrant urgent consideration by those in government advisory roles and by the MHRA. Having been a member of the Science and Technology Committee, I’ve seen how avoiding uncomfortable evidence can harm public trust.
“Governments must follow the data, not supress it. We already know that carcinogenicity or genotoxicity studies were not conducted for the Pfizer mRNA vaccine before its emergency authorisation in December 2020, so now would be a very good time to carry out long overdue independent post authorisation studies, particularly into potential causal links to cancer. The regulators and the government should be fully investigating mRNA risks. Instead, we are seeing huge investment into mRNA technology as the answer to many of our public health problems.”
Professor Dalgleish concluded: “In my opinion, this is no longer a hypothesis. The data are in. The mechanisms are understood. The signal is screaming. It is time to act.”
Biography of the speaker:
Professor Angus Dalgleish MD, FRCP, FRACP, FRCPath, FmedSci, a renowned oncologist with over three decades of experience in cancer immunotherapy. He was appointed as foundation chair of oncology at St George’s, University of London in 1991 and became professor emeritus in 2023. He has contributed significantly to the understanding of HIV and its link to cancer. He holds numerous fellowships and has authored or co-authored over 500 peer-reviewed papers. His book titles included the recently published The Origin of the Virus and The Death of Science.
Supporting references mentioned:
Study from Spain: Evidence of exhausted lymphocytes after the third anti-SARS-CoV-2 vaccine dose in cancer patients
Study from Japan: Increased Age-Adjusted Cancer Mortality After the Third mRNA-Lipid Nanoparticle Vaccine Dose During the COVID-19 Pandemic in Japan
Study from South Korea: https://link.springer.com/article/10.1186/s40364-025-00831-w
Study from Italy: https://www.excli.de/excli/article/view/8400
mRNA COVID-19 Vaccination and Cancer Risk: A Case-Based Review
View the full minutes for this meeting, held on Monday 16 March 2026.