A Vaccine for Meningitis

Meningitis is a life-threatening condition estimated by the World Health Organization to affect 300,000 to 350,000 worldwide each year, the majority of which are under the age of five. Now, a vaccine developed by Canadian chemist Harold Jennings is greatly reducing the number of meningitis cases worldwide.

Meningitis is most commonly due to an infection by certain strains of viruses and bacteria that consequently results in an inflammation of the meninges, the protective boundary surrounding the brain and spinal cord. While common symptoms include headaches and stiffness of the neck, more severe cases of the disease can result in hearing loss, permanent cognitive defects, and even death.

Dr. Harold Jennings works as a carbohydrate chemist at the National Research Council’s (NRC’s) Institute for Biological Science, and has made breakthroughs in the study of polysaccharides and their importance in pathogenic bacteria. Polysaccharides, or sugar polymers, can be found on the surface of microbes which consequently makes these molecules the first point of contact with the human immune system. The types of these polysaccharides and their compositions are specific to each bacterial variant, making them a good candidate for vaccine development.

Differing from the commonly developed vaccines based on proteins, Jennings managed to develop a conjugate that links the polysaccharides to protein carriers. Using the bacterium Neisseria meningitidis, as the target, injection of the conjugate resulted in a strong immune response toward three major strains of the bacteria. Furthermore, this vaccine was successful even in infants, which had previously proven to be a difficult roadblock to overcome. In 2000, Jennings’ group C vaccine was approved as part of a nation-wide immunization program in the United Kingdom, and is now saving lives worldwide.