Cancer refers to any one of a large number of diseases characterized by the development of abnormal cells that divide uncontrollably and have the ability to infiltrate and destroy normal body tissue. Research has proven that there are certain types of virus that can lead to the onset of cancer. To date, vaccines have proven very effective in preventing diseases caused by viruses and bacteria, you only have to look at Measles, Polio, Smallpox and Tuberculosis to see this.
Cancer refers to any one of a large number of diseases characterized by the development of abnormal cells that divide uncontrollably and have the ability to infiltrate and destroy normal body tissue. Research has proven that there are certain types of virus that can lead to the onset of cancer. To date, vaccines have proven very effective in preventing diseases caused by viruses and bacteria, you only have to look at Measles, Polio, Smallpox and Tuberculosis to see this.
Cancer vaccines can potentially cure cancer without unpleasant side effects.
In the examples of diseases (caused by viruses & bacteria) listed above, vaccines work by exposing people to a deactivated, or weakened form of the threat. This allows the immune system to identify specific markers (antigens) within the threat and mount a response. These vaccines typically work better in a preventive setting to ensure the body is fully prepared before being exposed to the genuine article. Developing a vaccine for cancer however, has proven to be a bit more complicated. Unlike bacteria and viruses, (which the body can fairly easily identify as being ‘foreign’), cancer cells more closely resemble our normal, healthy cells. Furthermore, each individual’s tumor is in some sense unique and has its own distinguishing markers (antigens). Both of these two main reasons have forced scientists into a more sophisticated approach when it comes to developing a cancer vaccine. Current cancer vaccine research appears to be focused in three main areas:
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Viral infections are responsible for the development of several cancers and preventive vaccines play an important role in reducing risk. For instance, cervical cancer and head and neck cancer can be caused by human papilloma virus, or HPV, whereas liver cancer can be caused by hepatitis B virus or HBV. Several vaccines have been developed that can prevent HBV and HPV infection and, as a result, protect against the formation of HBV- and HPV-related cancers.
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Fortunately, doctors can now identify targets on patients’ tumors that can help distinguish cancer cells from their normal cells. Sometimes these targets are normal proteins that are produced at abnormally high levels by cancer cells, such as prostatic acid phosphates (PAP), which is often 'over-expressed' by prostate cancer cells. Taking advantage of that insight, the sipuleucel-T vaccine was developed and received FDA approval in 2010 for the treatment of patients with advanced prostate cancer. Additionally, virus-derived proteins expressed by virus-infected cancer cells offer another promising source of markers that can be targeted through vaccines.
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In contrast to normal, yet 'over-expressed' proteins like PAP, tumors also display unique targets that arise as a result of mutations. These are referred to as neoantigens (new antigens) and they are expressed exclusively by tumor cells and not by any of a patient’s healthy cells. With neoantigen vaccines, therefore, it is conceivable that immune responses could be directed precisely against patients’ tumor cells while sparing their healthy cells from immune attack, thus possibly preventing side effects. Several types of neoantigen vaccines are currently being evaluated in clinical trials , both alone and in combination with other treatments.
