Single-administration vaccines: controlled-release technology to mimic repeated immunizations

The most effective mechanism for the elimination of disease from society is the use of vaccinations, but these often require repeated administration. However, single-administration vaccine formulations provide the repeated ad ministrations automatically. One approach is the development of injectable controlled-release microsphere formulations containing the vaccine antigen that is released as a pulse 1-6 months after injection. The time of the pul se is dependent upon the rate of polymer degradation, which is dictated by the polymer's composition and molecular weight. This controlled-release tec hnology may provide complete protection against disease after a single admi nistration.