Vaccines: past, present and future

Abstract

The vaccines developed over the first two hundred years since Jenner's lifetime have accomplished striking reductions of infection and disease wherever applied. Pasteur's early approaches to vaccine development, attenuation and inactivation, are even now the two poles of vaccine technology. Today, purification of microbial elements, genetic engineering and improved knowledge of immune protection allow direct creation of attenuated mutants, expression of vaccine proteins in live vectors, purification and even synthesis of microbial antigens, and induction of a variety of immune responses through manipulation of DNA, RNA, proteins and polysaccharides. Both noninfectious and infectious diseases are now within the realm of vaccinology. The profusion of new vaccines enables new populations to be targeted for vaccination, and requires the development of routes of administration additional to injection. With all this come new problems in the production, regulation and distribution of vaccines.

Figure 1. Pseudo-particles of human papillomavirus type 16 formed by self-assembly of the L1 viral protein.

Courtesy of Drs. John Schiller and Susana Pang.

Figure 2. Scanning electron photomicrograph of a microprojection array used to deliver antigen to the skin.

A 25-gauge needle is shown (at right) for size comparison. Figure reprinted from ref. courtesy of J. Matriano (ALZA Corporation) with kind permission of Springer Science and Business Media.