The Ideal Vaccine

A vaccine is a substance that causes the immune system to develop responses that protect against a specific disease. An ideal vaccine would be:

• safe;
• easy to manufacture;
• easy to administer; and,
• when administered in infancy, confer life-long immunity against all forms of the disease.

This ideal is rarely achieved, however, and some of our best licensed vaccines, such as tetanus toxoid, must be given repeatedly throughout life to maintain immunity. In practice, most vaccines do not actually prevent infection, but instead enhance the immune system to limit the pathogen's ability to cause disease. The vaccine stimulates antibody and T cell responses that can respond quickly to the infection and prevent the invader from causing serious clinical disease.

An ideal malaria vaccine would prevent all infection by priming the immune system to destroy all parasites, whether free swimming in the blood, while in the liver, or even, theoretically, while in red blood cells.

This degree of protection would be extremely difficult to achieve and might not be technically feasible with current vaccinology art and science. Many vaccine developers have therefore focused their efforts on creating a vaccine that limits the ability of the parasite to successfully infect large numbers of red blood cells. This would not prevent infection but would limit the severity of the disease and help prevent malaria deaths.

…Vaccine Challenges