Doctors Testify at Senate Hearing: Possible Links Between COVID Injections and Cancer

Doctors and researchers told a US Senate subcommittee on Tuesday that there may be plausible links between COVID-19 injections and rising cases of aggressive cancers. The hearing on 3 June 2026, chaired by Senator Ron Johnson of Wisconsin, examined clinical observations and potential biological mechanisms.

Witnesses included leading oncologists who described unexpected patient outcomes following boosters, while counter-testimony stressed the absence of proven causation in major studies. The session has drawn attention to debates over vaccine safety amid continued use of mRNA technology.

Oncologists Report Surge in Aggressive Cancers After Boosters

Professor Emeritus Angus Dalgleish, an oncologist from the University of London, testified that he first noticed a pattern in late 2021 of cancer relapses in patients who had been in stable remission for years. These relapses consistently followed repeated COVID-19 booster administration. 'Beginning in late 2021, I observed a series of unexpected cancer relapses and unusually aggressive disease presentations among patients whose conditions had remained stable for years,' he said.

Dalgleish pointed to potential immune dysregulation from repeated boosting, including exhausted T-cell responses. He also raised concerns over residual DNA fragments and SV40 promoter sequences in certain vaccine lots, calling for greater regulatory scrutiny.

The professor urged an urgent independent investigation into the relationship between mRNA vaccination and cancer progression in vulnerable groups. His observations were echoed by other experts citing aggressive tumours in younger adults and rapid recurrences.

Microbiome Expert Links Injections to Gut Bacteria Depletion and Disease

Dr Sabine Hazan, chief executive of ProgenaBiome, focused on microbiome changes. Her research showed mRNA vaccines sharply reduce levels of Bifidobacterium, a bacterium essential for immune regulation and gut health. 'Follow the killing and disappearance of bifidobacteria in the gut and understand why disease starts especially cancer,' Hazan told senators.

Data presented at gastroenterology conferences indicated persistent post-vaccine damage to the microbiome, with depletion also seen in various cancers. She noted that restoring Bifidobacterium has correlated with clinical improvements in other conditions.

This adds to the body of case reports suggesting temporal associations between vaccination and cancer signals. A peer-reviewed overview published this year examined 69 studies involving hundreds of patients across 27 countries. These findings, though preliminary, have prompted calls for further mechanistic studies.

Officials Insist No Evidence of Causation Despite Public Concern

Countering the claims, Dr Julie Gralow of the American Society of Clinical Oncology stated there is 'no clinical evidence proving that mRNA COVID-19 vaccines cause cancer'. She explained that cancer typically develops over years or decades, making the appearance of late-stage tumours within weeks or months of an injection biologically incompatible with established knowledge.

Large population studies, including one involving nearly 30 million people, have shown vaccinated individuals were less likely to die from cancer years later. The National Cancer Institute, funded to the tune of £5.5 billion ($7.35 billion), has similarly found no increased risk.

Senator Richard Blumenthal cited the institute's conclusion of no evidence linking vaccines to cancer recurrence or progression. An Instagram post reacting to the proceedings described it as sparking uproar over vaccine safety and alleged cover-ups, amplifying calls for greater transparency.

The hearing concluded without immediate policy shifts but underscored the need for open scientific debate. As fresh data emerges, experts on both sides agree more research is essential to address lingering questions about COVID-19 injections and potential cancer links.