If you are over 60, you may remember standing in line to get the polio vaccine when it was introduced in 1955. If you are younger, polio is probably just a quaint disease you learned about in school. Polio and smallpox have been eradicated by global vaccination programs. In developed countries, measles, mumps, whooping cough, and diphtheria are rare except in pockets of children whose parents have chosen not to vaccinate them thinking the danger of disease is lower than the danger of vaccination side effects.
These vaccines work because the vaccine stimulates the body to produce disease-fighting substances called antibodies that protect against that specific disease. Antibodies "remember" the virus or bacteria and will attack it years later if the body encounters that germ again. This is the way the new vaccine for cervical cancer works.
But what about breast cancer? So far no one has found a virus that causes breast cancer, so how could there be a breast cancer vaccine? Most of the researchers who have worked on finding a breast cancer vaccine have tried to strengthen the body's immune system and persuade it to attack breast cancer cells as if they were a virus.
A 2007 article by PJ Hamel reviews the history of the hopes for breast cancer vaccines that have come and gone over the years. Most of these vaccines have focused on curing an existing breast cancer and/or preventing a recurrence.
The newest in this series of hopes for a vaccine was explained in an online article in Nature May 30, 2010. Researchers at Cleveland Clinic in Ohio have produced a vaccine that has prevented breast cancer in mice that have a gene for breast cancer. This vaccine takes a different approach from some others by trying to find a way to prevent breast cancer, not cure it, just like those vaccines we know from our childhood.
To do this, the vaccine uses a protein called alpha-lactalbumin which is found in most breast cancers. The vaccine signals the body to destroy the protein, but not regular breast tissue. Without the protein, the breast cancer doesn't develop. Because alpha-lactalbumin is found in healthy women only when they are breast-feeding, the idea is to use the vaccine after child-bearing years, but before the average onset of breast cancer.
CNN quotes Dr. Vincent Tuohy, the study's lead researcher, "We can protect women from breast cancer, but if [the vaccine] destroyed their normal breast, it's an unacceptable side-effect, so we had to avoid that. . . . It's kind of like an application of immunologic judo, using the natural changes that occur in a woman's needs. A decrease in the use of the breast for breastfeeding, and an increase in the breast's risk of developing tumors. We're taking advantage of that. That hasn't been done before."
The new approach worked with the mice and offers great promise in people. So what happens next? This is not the first time an experiment worked in mice. What works in mice often fails in humans.
