Taking on infectious disease
Vaccines may be one of the most important achievements in medical science-and, given the threat of new and re-emerging infectious diseases, they are more important than ever.
"The time has come to close the book on infectious diseases." When US Surgeon General William H. Stewart wrote those words in his 1967 annual report, he was reflecting the mood of the time. The optimism appeared to be warranted: antibiotics had significantly reduced the incidence of many diseases in North America. It seemed only a matter of time before we got the upper hand on disease-causing micro-organisms such as viruses, bacteria, and parasites.
But that was then; this is now. Today's reality is that infectious diseases pose a rising global health threat. As it turns out, the pathogens that cause them have an extraordinary ability to change over time. We are now faced with an onslaught of newly identified infectious diseases, such as SARS, and re-emerging infectious diseases, such as tuberculosis, malaria, and cholera. Of the new diseases, 80% are zoonotics -diseases caused by infectious agents that can jump from animals to humans. Avian flu is an example.
"Infectious agents are much smarter than we are. Their evolutionary ability will ensure their survival." That's the opinion of Dr. Lorne Babiuk , an international authority in virology and immunology and now vice-president (research) at the University of Alberta. Before coming to Alberta, Dr. Babiuk was director of the University of Saskatchewan's Vaccine and Infectious Disease Organization (VIDO). Under his leadership, VIDO became internationally recognized for its role in the use of biotechnology to develop vaccines. The world's first genetically engineered vaccine for animals was developed at VIDO.
"The kind of thinking behind the surgeon general's optimism isn't prevalent today," says Dr. Babiuk. "The scientific and medical community sees the threat. There's a renewed focus on infectious disease, which has spurred research on vaccines and resulted in a very significant increase in the number of vaccines available.
"Oddly enough, the incredible success of vaccines is a problem. Most people in North America don't come face to face with the threat of devastating infectious disease anymore. They didn't live through the days when a disease like polio terrified families, when hospitals were filled with patients in iron lungs. As a result, immunization rates are dropping. And we're hearing more and more from the anti-vaccine lobby. The reality is that there is no scientific doubt about the effectiveness of immunization. I believe vaccines are one of the greatest achievements of medical science. They dramatically cut deaths from disease. But we've become complacent, and we're putting public health at risk.
"Vaccines work. And research continues to improve them. As we understand more about the protective components of infectious agents and how the human immune system functions, we are able to be more specific in the formulation of vaccines. The amount of antigen -the ‘active ingredient' in vaccines-needed to induce the appropriate immune response can be reduced by about 25%. We're also seeing innovations in needle-free vaccine delivery, with more vaccines designed to be administered orally or nasally.
"Basic research done in universities is critical for vaccine development. University researchers are teasing out key details about the immune system-fundamental knowledge that can be applied in the development of a wide range of vaccines. Many university researchers work on diseases that don't grab the attention of drug companies, so they play an important role in making advances in treatment for these so-called orphan diseases.
"A great deal has been accomplished, and a great deal more needs to be accomplished. We'll always be playing catch-up with infectious agents."