In 2012, the World Health Organization declared that cervical cancer should be classified as a rare disease due to the success of vaccination programs. In less than 10 years, HPV-associated cancers have dropped by nearly 90%. Researchers are now looking for a vaccine against other types of cancer–such as breast and prostate cancers.
– Cervical cancer is the most common of all cancers caused by an HPV infection.In fact, cervical cancer was once the fourth leading cause of death from cancer in women. Today it is the third most common type of cancer in women between 15-44 years old.
Most of the women affected are from developing countries where early detection is difficult, causing most cases to go undiagnosed when they are in advanced stages. About 4% of women survive 5 or more years after being diagnosed.
Two types of HPV vaccines exist and both protect against cervical cancer: Gardasil, manufactured by Merck, and Cervarix, made by GlaxoSmithKline. A third vaccine against some types of HPV is currently being tested in clinical trials.
However, some studies suggest a more effective vaccine could be developed if it were able to protect against all types of HPV that cause cancer instead of just two; or if it were able to protect against HPV types that can cause cancer in the vagina, cervix, anus, mouth and throat.
A recent study published in Cancer Prevention Research suggests there might be one way to do just that. Researchers found that vaccinating mice with an adjuvant composed of a mixture of three widely used food additives not only provided protection against 4 types of HPV but also helped prevent infection by other high-risk viruses linked to cancer.
Scientists from the University of Texas Medical Branch at Galveston found that when they used the adjuvant in mice, their bodies responded with an immune response that was able to produce a strong and specific cytotoxic T cell response against HPV types 16 and 18. HPV types 16 and 18 cause about 70% of cervical cancer cases worldwide.
HPV vaccines induce tumours in some animal models, so it is very important to understand the mechanisms involved in virus-induced cancers and how to prevent them, said co-author of the study Professor Catherine Fields. We found that vaccination with adjuvant composed of food additive elicits a strong cytotoxic T cell response against HPV types 16 and 18 that could provide cross-protection against other high-risk HPV types, potentially reducing the probability of developing additional HPV-related cancers.
The UTMB researchers point out that although this adjuvant has not yet been tested in humans, it is composed of food additives already approved by the U.S. Food and Drug Administration for human consumption. Furthermore, they claim that this new vaccine could be less expensive to make if vaccines are produced with adjuvants rather than with whole virus particles.