ABSTRACT
Vaccination has traveled a long road since the contents o f smallpox pustules were used to inoculate individuals.1 Whilst vaccines consisting o f attenuated or inactivated whole organisms are still in use, advances in recombinant D N A technology have unleashed the potential o f subunit vaccines. Subunit vaccines contain specific antigenic substances that have been expressed and purified using recombinant D N A technology. The production and purification o f recombinant antigens may be time consuming and relatively expensive; how ever the reduced exposure to the pathogen decreases the patient complication rate. This aspect has persuaded health administrations and product manufacturers to favor the subunit approach over other vaccine strategies.2
