Scientists have begun to understand the inner workings of human disease at the molecular level with the advances in genomics، proteomics and computational power.
Today with the increased knowledge we are better placed to use this knowledge in the development of new and effective drugs. In 1900، three illnesses، pneumonia, tuberculosis and diarrhea caused a third of all deaths in the United States. Only pneumonia is still on the list of 10 most common causes of death. The life expectancy in 1900 was 50 years as against 77 years in 2000، and this was achieved to a large extent by not only improvements in sanitation and hygiene but also to the availability of drugs to control infection, hypertension, hyperlipidemia, and to some extent even cancer.
Posssibly the earliest written record of medical therapeutics is contained in the famous Ebers papyrus, a 20-metre-long, 110-page medical scroll, named after the German Egyptologist Georg Ebers, who acquired it in 1872.
This valuable document described hundreds of treatments for the many aliments inflicting ancient Egyptians around1500 BC. These concoctions were prepared by mixing together various herbs, shrubs, leaves, inerals, and animal excreta. These must have had a strong influence on later generations when knowledge of herbal products became more organized, as evidence by Greek, Roman, and Indian cultures, as well as traditional Chinese medicine.
The history of drug discovery in the pharmaceutical industry and academic labs over the past half-century shows a progression of discovery paradigms that began shortly after“miracle drugs” such as the penicillins became available to the public after World War II. That same decade also saw the rise of synthetic organic chemistry which had progressed to the point that the large scale preparation of “non-natural” drugs or drug candidates was economically feasible.
The development of small molecule therapeutic agents for the treatment and prevention of diseases has played a critical role in the practice of medicine for many years.
In fact, the use of natural extracts for medicinal purposes goes back thousands of years; however, it has only been in the past half century or so that searching for new drugs has found itself in the realm of science.
Salicyclic acid, the precursor of aspirin, was isolated in 1874 from willow bark. Other more potent painkillers, such as morphine and codeine, were isolated from the opium poppy. The anti-malarial agent, quinine, was separated from cinchona (china bark). The leaves of the purple foxglove plant provided an excellent source of digitalis that was purified for use against heart disease. There are numerous other examples. Although synthesis of the first synthetic pharmaceutical drug, aspirin, occurred in the latter half of the nineteenth century, it was not until the early 1900s that the recognition of aspirin as a universal pain reliever was realized and this discovery spawned the era of therapeutic agents.
In the past 50 years, vaccines have saved more lives worldwide than any other medical product or procedure. But the fascinating story of vaccination goes back all the way to ancient Greece when in 429 BC Thucydides noted that sufferers of smallpox who survived did not become reinfected. China was the first country to use a form of vaccination called variolation in 900 AD, in which healthy people were exposed to tissue from scabs by placing it 16 under the skin or in powdered form was inserted up the nose with the aim of preventing small pox from occurring. In 1796 Edward Jenner from England discovered vaccination in its modern form. Louis Pasteur improved on the vaccine and developed one against rabies in the 1880s. In 1890, German scientist، Emil von Behring, was awarded the first Nobel Prize in Physiology or Medicine for discovering the basis for vaccination against diphtheria and tetanus.
Shibasaburo Kitasato discovered the antitoxins of diphtheria and tetanus. In 2008, Professor Harald zur Hausen, the scientist who discovered that cervical cancer was caused by a group of viruses called human papillomaviruses (HPV) received the Nobel prize. This discovery made it possible for scientists to develop a vaccine, the HPV vaccine، for cervical
There has been renewed interest in Vaccine research and development (R&D) particularly as health care authorities increasingly acknowledge the benefits and costeffectiveness of vaccination. These efforts have saved lives، decreased human suffering, and reduced health care costs, thus protecting the well being of individuals and societies around the world.
Several factors have fuelled these efforts, including the lack of vaccines currently available for several major infectious diseases (e.g. malaria, hepatitis C, and acquired immunodeficiency syndrome, AIDS); the need for viable alternatives to antibiotics to help fight infection; concerns regarding emerging infectious diseases as well as potential threats such as pandemic influenza and bioterrorism.
The development of a safe and effective prophylactic vaccine against HIV/AIDS is one of the highest priorities of the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health (NIH). Numerous experimental prophylactic HIV vaccines have been tested in human clinical trials. Only three large-scale HIV vaccine efficacy trials have been completed to date: two provided no evidence of efficacy despite the fact that the vaccines induced an immune response in many trial participants, then most recently, products tested in a third trial in Thailand demonstrated modest efficacy at preventing HIV infection.
The significant results from this latest trial have recharged the HIV vaccine field and highlight the importance of testing promising HIV vaccine concepts in carefully planned clinical research studies. Other developments include a highly efficacious vaccinia-based dual vaccine against small pox and anthrax, DNA vaccines against parasitic disease, tropical disease vaccines, malaria vaccine, Group B Streptococci conjugate vaccine, Newer TB vaccines, plant derived vaccines, and novel adjuvant systems.