Health Canada has recently confirmed the presence of a Simian Virus 40 (SV40) DNA sequence in the Pfizer COVID-19 vaccine, which the manufacturer did not initially disclose.
This revelation has sparked a debate among scientists about its potential risks, with some suggesting it could potentially cause cancer, while others downplay the threat.
The regulator expressed its expectation for sponsors, like Pfizer, to identify any biologically functional DNA sequences, including the SV40 enhancer, during the submission process. Despite providing the full DNA sequence of the plasmid, Pfizer did not specifically highlight the SV40 sequence.
Scientists Kevin McKernan and Dr. Phillip J. Buckhaults raised concerns about the presence of SV40 enhancers in the vaccines. McKernan, a former MIT researcher, suspects Pfizer omitted this information due to SV40’s historical association with polio vaccines. While there’s no evidence it’s carcinogenic, integration into the human genome raises concerns.
The SV40, an oncogenic DNA virus, was previously removed from polio vaccines due to cancer-related concerns. Dr. Buckhaults, a cancer genomics professor, reassured that the SV40 sequence in the vaccine is not the cancer-causing variant, emphasizing that it poses a relatively small cancer risk.
Dr. Patrick Provost, a microbiology professor, explained that the danger lies in the potential integration of SV40 enhancers into a cell’s DNA genome. If it occurs, it could initiate a cancerous process. Additionally, the encapsulation of contaminating DNA fragments in lipid nanoparticles may pose a unique risk, potentially rendering existing thresholds irrelevant.
McKernan emphasized the redundancy of including the SV40 promoter in Pfizer’s vaccines and expressed concerns about its integration into human genomes. Angus Dalgleish, an oncology professor, also highlighted the potential risks of DNA plasmid and SV40 integration in cancer development. However, it’s essential to note that these concerns remain hypothetical and have not been scientifically proven.
Dr. Janci Lindsay, a toxicology expert, pointed out that plasmid DNA sequences, like the SV40 enhancer, could potentially contribute to cancer development. If integrated into the human genome, it could lead to gene mutations that cause cancers. Dr. Lindsay also raised questions about why Pfizer did not disclose the presence of the SV40 enhancer to regulatory agencies.
Despite these concerns, Health Canada maintains that after an independent review, the risk/benefit profile supports the use of the Pfizer-BioNTech vaccine. They stress that they do not rely solely on the conclusions of vaccine manufacturers, but conduct a thorough assessment of the provided evidence to ensure safety, efficacy, and quality standards are met.