Imagine having the ability to eliminate a disease—not just to alleviate its symptoms, but to erase it completely, as if it had never existed. This is the promise of vaccines.
It was this idea that lured me, as an undergraduate, into the field of immunology. A few years after my grandmother had died of melanoma, I was browsing in the library stacks when I came across a research article discussing a vaccine-based therapy for the cancer. The concept gave me pause. I had only known vaccines in the context of the dreaded childhood shots. Yet here, the authors presented the idea of tweaking vaccination so that the immune system might reject cancer in much the same way that it clears an infection.
Cancer vaccines still remain more a goal than a current therapy, but the design of successful vaccines offers firsthand evidence that the human immune system can be tricked and manipulated to behave as we would like.
This issue of The Scientist celebrates vaccines. It catalogs how a fuller understanding of the intricacies of generating immunity is informing vaccine design. The articles herein focus on diseases that present unique challenges to vaccine development.
Feisty as it is, the immune system remains an unconquered landscape still harboring many secrets.
While our ever-adapting immune system is nimble, some pathogens, such as the HIV and influenza viruses, are even more nimble in their evolution and immune evasion. For this reason, Gene Shearer and Adriano Boasso have resurrected the idea of designing a vaccine to target a human protein displayed on the envelope of the HIV virion, a protein over which the virus has no control. They explain how such a vaccine could stop viral spread by eliciting the kind of fierce immune response seen in organ-transplant rejection. Vaccinologist Rino Rappuoli reviews current efforts to make “universal” vaccines that could circumvent pathogens’ incessant self-modification.
Another major challenge to the production of new vaccines is the cost associated with their development and their distribution. Like other pharmaceutical products, vaccines are estimated to cost as much as a billion dollars each to bring to the clinic, while the income they generate is usually limited to a three-time application per susceptible person. Brad Spellberg discusses the underexplored market for vaccines against fungal infections that kill many patients who acquire them in hospital settings.
In a Critic at Large article, Michael Gusmano makes the point that vaccines must be viewed as complementary solutions to the problem of malaria in areas of the world where millions of people still suffer and die from the disease—true resolution needs to include the implementation of effective local and national public-health systems.
The principles underlying vaccination have inspired applications beyond infectious disease. Thomas Kosten discusses developing vaccines that might help users of addictive drugs break the habit. Blocking the drug’s access to the brain via antibody binding of cocaine deprives users of the pleasure—though not the craving—associated with the drug. However, the vaccine, coupled with behavior-modification therapy, could help patients struggling to maintain sobriety.
Vaccines activate one of our most versatile biological systems—one so adept at preventing microbes from taking over our bodies that it can guess the molecular signature of pathogens it has never encountered. Feisty as it is, the immune system remains an unconquered landscape still harboring many secrets. As the list of immune-related diseases grows, from rheumatoid arthritis, to diabetes and Alzheimer’s, and of course, cancer, one can only hope that we can do for these what vaccination has done for many infectious diseases.