How cancer therapy benefits from mRNA-based COVID-19 vaccines.
For decades, researchers have been working on the development of cancer vaccines. The impact of cancer research findings on the rapid production of a COVID-19 vaccine is clearly evident. Guido Wollmann of the Institute of Virology recently explained in a press release from the Medical University of Innsbruck1 why cancer therapy is now in turn benefiting from the current state of COVID-19 vaccine research.
The advancement of vaccine technologies in cancer vaccination is in part an important reason for the rapid development of mRNA-based COVID-19 vaccines, according to Wollmann. These RNA platforms, which can be individually engineered with RNA elements of SARS-CoV-2 or tumor mutations, have been proven in cancer therapy for years with clinical trials and are associated with very good core outcomes.
The mass application of COVID-19 vaccination, in turn, contributes to the fact that there is now little room for argument regarding regulatory processes, such as safety profiles, clinical trial phases, as well as the upcalling process, with respect to the approval of novel, biologic therapy platforms. This will favor future research and development of cancer vaccines.
Mode of action differences between mRNA and vector vaccines.
By adding short-lived genetic information – such as a viral protein or an endogenous tumor protein, among others – to the mRNA vaccine, the body’s own cells produce a protein with it. In doing so, it tries to encode only the area of the mutation. These are thus components of a tumor without function, which are only recognized by the immune system.
In vector vaccine, the viruses are almost completely unenucleated, equipped with genetic information components of the SARS-CoV-2 as a piece of DNA and used as a ferry so that the body can continue to recognize the unenucleated virus as an active virus and generate an anti-vector immune response in addition to the COVID-19. Oncolytic viruses, on the other hand, are not denucleated, as they are only intended to replicate in the tumor. When injected specifically into the tumor, these viruses attack the cancer, triggering inflammation that the immune system eventually becomes aware of.
Wollman says that research on vector-based cancer therapies can benefit from understanding the immunological interaction between the immune response against the corona or tumor protein and the anti-vector immune response. The current intensive research into “COVID-mixed vaccines” also draws parallels with several study approaches that have been investigated in experimental cancer therapy for more than a decade, exploring the body’s response to cancer vaccine combinations.
Adenovirus-based vector vaccines and advances in viral tumor therapy.
Adenoviruses have since been generating effective yet temporary immunity. The manufacturers of the only four adenovirus-based COVID vector vaccines approved worldwide utilize different subtypes of adenovirus, very rarely found in humans, to exclude pre-existing vector immunity. Because of this immunity to specific adenoviruses, oncolytic adenoviruses and other oncolytic human viruses are injected directly into the tumor in tumor therapy.
“T-Vec,” which is based on a modified herpes virus and was approved in 2015 in the U.S. and Europe as the first oncolytic virus for tumor treatment of malignant melanoma, has recorded very good treatment success, according to Wollmann. Because this specifically infects and destroys the cancer cell being treated and triggers a strong immune response against the tumor mutation – thus preventing regeneration – T-Vecs demonstrates a high response as well as survival rate and enables long-term control up to tumorigenesis. Wollmann expects this success for all oncolytic viruses, as a broad spectrum of clinical studies concerning oncolytic viruses is now almost seamlessly combined with immunotherapy.
About the tolerability of cancer vaccines
Asked whether cancer vaccines are tolerable and whether they carry side effects, Wollman replied that RNA use is considered generally safe and that the side effect profile of cancer vaccines is much lower compared with chemotherapy. Part of the immune response, he said, is flu-like treatment responses that are specifically activated in the body. Only the extremely rare allergic reactions are due to the nanoparticle shell of the RNA protective bubble and only if there is a history of allergy to the stabilizer polyethylene glycol (PEG).