Cancer drugs inhibit benefits of mRNA Covid-19 vaccines

Cancer drugs inhibit benefits of mRNA Covid-19 vaccines

Mayo Clinic researchers have found that a wide array of anticancer drugs renders Covid-19 mRNA vaccines far less effective at boosting the cancer patient's immune system.


Cancer patients who are taking anti-cancer drugs in the UK are being pestered by their doctors to have a Covid-19 vaccination or boosters but important new research suggests that their drugs can block the effectiveness of mRNA vaccines and there may not be much benefit in these mRNA shots.


Ibrance, leukaemia, lymphoma drugs, not just basic chemo


Mayo Clinic researchers have found that patients who are receiving chemotherapy treatment, or CDK4/6 inhibitors such as Ibrance, or therapies for blood and lymph cancers targeting B-cells, are receiving drugs that prevent the Covid-19 mRNA vaccines from providing an adequate immune response.


Dr. Sarayna Chumsri, who led the study, was surprised by the number of cancer drugs that actually neutralised the vaccines. In particular, many strong positive claims are made about the new CDK 4/6 inhibitors used to treat Er+ve and HER2-negative breast cancers, yet they were almost the worst for depleting the vaccines..

Dr. Chumsri recommended that antibody levels be tested in all cancer patients after vaccination and, if still low, suggested they receive booster vaccinations immediately. 

Dr. Chumsri continues to study the relationship between the mRNA vaccines and anti-cancer drugs, analysing broader immune responses at the cellular and antibody levels, particularly for booster shots.

The problem may lie only with the mRNA vaccines, widely adopted in America yet surprisingly used as the booster shot whatever vaccine went before it in Europe. The new protein-based vaccines may however offer some hope of more effectiveness and more safety, as they have been widely used since 1947 and clashes with drugs have been well studied. The first ‘old-style’ protein-based Covid-19 vaccine, Novavax, has already received approval from South East Asia, Indian and European regulators plus the World Health Organisation.


Go to: Novavax leads the way in new ‘old-style’ protein based vaccines




  1. Saranya Chumsri, Pooja P. Advani, Tanmayi S. Pai, Zhuo Li, Ashita Mummareddy, Marites Acampora, Gina A. Reynolds, Natasha Wylie, Ashton W. Boyle, Yanyan Lou, Kabir Mody, Alvaro Moreno-Aspitia, Melanie D. Swift, Abinash Virk, Adil E. Bharucha, Christopher P. Marquez, Tushar C. Patel, Gregory J. Gores, Keith L. Knutson. Humoral Responses after SARS-CoV-2 mRNA Vaccination and Breakthrough Infection in Cancer Patients. Mayo Clinic Proceedings: Innovations, Quality & Outcomes, 2021; DOI: 10.1016/j.mayocpiqo.2021.12.004



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2022 Research
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