While the earliest documented examples of vaccination date to 10th century China, the first vaccine wasn’t developed until 1796; its target, smallpox, was eradicated worldwide in the late 1970s – a profound accomplishment.
There have been other notable successes using 20th century vaccine technology:
- Diphtheria, mumps, pertussis, and tetanus: there has been a greater than 92% decline in cases and a 99% or greater decline in deaths due to these diseases using vaccines recommended before 19801.
- Poliovirus, measles and rubella: endemic transmission has been eliminated in the U.S.
- Smallpox was declared eradicated in 1979.
While there has been continued success and increased availability of vaccines over the last century, the development timelines have not shortened and many hard to treat diseases of the late 20th century continue to defy a vaccine solution despite billions of dollars being spent on their development. These diseases include:
- Herpes (HSV-1, 2; CMV)
- Cancer vaccines for a variety of malignancies
Much of the vaccine development effort has focused on using conventional vaccine technologies such as live attenuated (weakened or killed), inactivated, sub-unit, or recombinant antigens. More recently, the use of virus like particle (VLP) vaccines has gained attention with the successful approval of HPV (GARDASIL® and Cervarix®) and hepatitis B virus preventive vaccines. However, potential safety concerns associated with live/inactivated approaches as well as lack of broad immunogenicity associated with recombinant/VLP approaches has meant that new vaccine development has taken 30+ years from research to market. Indeed, for diseases like HIV and malaria there isn’t an effective vaccine on the market despite 30-50 years of determined research.
Today, a growing understanding of cancers and pathogens, the relatively new knowledge of genetics (genomics), and the advancement of other technologies has enabled the exploration of an array of new approaches to stimulate the immune system. Inovio is playing a leading role in the effort to develop a new generation of vaccine technology.
The timeline below shows key historical milestones in the development of vaccines and, most recently, one of the most important emerging vaccine technologies: synthetic vaccines. The newest developments may be instrumental in overcoming the weaknesses of vaccine technologies used to date, preventing and treating an array of diseases with unmet treatment needs and accessing significant commercial opportunities.