Uschi's Thoughts

An explanation of the vaccine !!!!!

We have all been watching the news lately regarding the terrifying Ebola virus. We have seen the great suffering and death that it has caused in Africa, and we have watched helplessly as the disease has crossed the borders from one country to the next. We have even seen it vault the ocean, respecting no boundaries, political or physical, to come to America. We have all felt that sense of insecurity and dread as we have asked, “Why have we not developed a vaccine? We have eradicated smallpox, polio is almost gone, and one hardly hears of mumps, measles and rubella anymore-all thanks to vaccination. We have known of Ebola since the 1970s. Why then has no one developed a vaccine?” An effective vaccine could allow us to forever close our borders, and the borders of all nations, to this intolerable threat.

My purpose today, however, is not to discuss Ebola. Rather is it to highlight another threat; an internal threat. The disease I wish to speak of is cancer. Cancer is not an infection. Instead, cancer happens when cells from our own body begin to grow and divide out of control. First they form a tumor. But like Ebola, malignant cells also respect no borders, and they chew through surrounding normal tissues (a process called invasion), and individual cells break off to form new tumors elsewhere in the body (a process called metastasis). These growing lesions disrupt the function of vital organs, eventually leading to death. Advances in surgery, drug therapy and radiation have steadily reduced death rates for most cancers. Nonetheless, the disease remains a major health problem, and the radical surgeries, harsh chemotherapies and daunting radiation treatments make cancer one of the few remaining diseases where the therapies are feared almost more than the malady itself. Cancer survivors can never be completely free from the concern their ordeal will return. If only there were a vaccine for cancer!

Fortunately, scientists are not neglecting the vaccine approach to protect us from cancer. One physician-scientist in particular, Dr. Brian Czerniecki of the University of Pennsylvania, has had remarkable success with an early form of breast cancer called ductal carcinoma in situ, or DCIS. A large proportion of breast cancers produce a protein called HER-2, and this is the target of Dr. Czerniecki’s vaccine. The vaccine is provided to the cancer patient once a week for four to six weeks after which the remaining tumor is surgically removed. After treating more than 80 patients since 2004, it was found that one out of five of those vaccinated had “complete responses”, i.e. no remaining tumor was found at the time of surgery. What’s more, Dr. Czerniecki can detect long-lived immune responses in the patients up to several years after vaccination. This alone suggests the possibility of long-term protection, but even stronger evidence is that none of the patients who have had complete responses to the vaccine have ever experienced a recurrent breast cancer! When compared to other experimental cancer vaccines being tested, this approach appears to induce much higher response rates as well as longer-lasting immunity. Although the initial focus is on breast cancer, it is likely that Dr. Czerniecki’s basic platform can be adapted to other carcinomas including colorectal, prostate, some lung cancers, and others.

Dr. Czerniecki also made another surprising discovery during the course of his vaccine study. He found that healthy individuals with no history of breast cancer had relatively high proportions of T cells (a type of white blood cell of the immune system) that could specifically recognize and react to the HER-2 tumor target. Interestingly, when he examined the blood from unvaccinated DCIS patients, as well as those who had progressed to invasive breast cancer, and then to metastatic breast cancer, he observed a progressive loss of HER-2-recognizing T cells. By the time the tumors became invasive, there were almost no anti-HER-2 T cells at all! It was as though the growing tumor, through some as-yet unknown means, was disabling or eliminating the very cells of the immune system that could protect us from cancer, through their ability to recognize and kill tumor cells that produce HER-2 vaccine target.

Interestingly, however, Dr. Czerniecki found that his vaccine could restore the numbers of HER-2-reactive T cells to levels near that of individual who had never had cancer. This “immuno-restoration TM” may prove key to long-term protection from future malignancies.

These are exciting times for the development of vaccines against cancer, and more work needs to be done before we reach our goal. It is imperative that Dr. Czerniecki’s work be continued so that a safe and effective anti-cancer vaccine can be a reality. Only then can we forever close our borders to deadly cancers.