The people behind the vaccine

Two centuries ago 'vaccinia' was introduced by Edward Jenner; atleast nine major diseases have since then been controlled by the use of vaccines. In the absence of vaccination, millions of children and adults could contract serious diseases, and many would have long-lasting effects or even die - hence it is one of the most important public health measures for preventing disease. People honors the pioneers whose contributions revolutionized immunization techniques in medical science.

Vaccines are a special type of drug. They contain variations of the tiny organisms that cause diseases like polio. When people take a vaccine, their bodies learn to fight these organisms. As a result, people don't get the disease.



Controlling deadly diseases
Immunization programs ultimately aim at preventing and possibly eliminating infectious diseases. In case of diseases that can only be transmitted from person to person, immunization results in the elimination of the disease and eventually, the eradication of the organism that causes it. This was the case with smallpox, and may very soon be the case with diseases like polio and measles.

Several other deadly diseases have been controlled as a result of vaccines. Diseases that once caused thousands of childhood deaths in the United States each year are now a rare occurrence. Vaccination has resulted in the elimination of polio from the Western hemisphere. Diphtheria declined from a high of 206,939 cases in 1921 to just one in 1998; whooping cough declined from 265,269 cases in 1934 to 6,279 in 1998; and measles fell drastically from 894,134 cases in 1941 to just 86 in 1999.


Several other vaccines have been used in individuals at risk from disease of such as rabies and plague, but have not been systematically applied on a global scale. While BCG has been widely administered to newborns, thus successfully preventing complications such as meningitis and miliary tuberculosis, administration of the vaccine has not resulted in control of the disease.


Successes in vaccination

Eradication of smallpox 
Smallpox was a highly contagious, rapidly spreading disease. It affected people of all ages, leaving scars on the face and body and often causing death. During the 15th century, an early form of smallpox vaccination was practiced in China and other parts of the world. Healthy people were intentionally infected with substances from the pustules of people suffering from smallpox, a technique called variolation. A mild form of smallpox usually resulted from this practice.


Edward Jenner (1749-1823) -
was the first to prove by scientific experiment that cowpox gives immunity against smallpox. He was the founder of virology and a pioneer of vaccination.

Jenner was born in Berkeley, Gloucestershire, on 17 May 1749, the son of a vicar. Working as a surgeon's apprentice, he went to London to study anatomy and surgery under John Hunter at St George's Hospital in London. Returning to Gloucestershire in 1773, he set up in private practice in Berkeley.


Smallpox was the most common disease in 18th century England and caused 20% of the deaths in London. It was during this time that Edward Jenner, an English doctor, developed the first vaccine in 1796. He had heard that dairymaids who had been infected with cowpox, a disease related to but milder than smallpox, were not susceptible to smallpox, and got his inspiration from this fact. By injecting a boy with material taken from lesions of cowpox he found that the boy became immune to smallpox. This was the first vaccination ever. In fact, the word vaccination comes from the Latin word for cow, vacca. Edward Jenner published his findings in 1798 and within three years 100,000 people in Britain had been vaccinated.


In the 19th century, vaccination laws were established in Europe and the United States, and people began to be vaccinated against smallpox as a routine. In the 20th century, vaccination against smallpox became a global effort. The last case of smallpox in the world was in Somalia in 1977.Another path-breaking invention in vaccination was the Pronged Vaccinating and Testing Needle by Benjamin A. Rubin.

Smallpox was a dreaded disease, killing at least two million people annually until 1967. The disease could be controlled by vaccination, but the vaccine itself was always in short supply or difficult to administer, especially in undeveloped areas of the world. Rubin ground the eyelet of a sewing machine needle into a fork shape to create a vaccine delivery system that helped wipe out the killer disease smallpox.


As a microbiologist for Wyeth Laboratories, Rubin first began to experiment with alternatives to the conventional syringe needle in 1965. Further refinements to his ground-sewing-needle design yielded the now-familiar bifurcated (fork-shaped) needle, which he discovered would hold enough vaccine to inoculate a person with a few jabs. Rubin's needle sped vaccinations worldwide. In 1980, scientists announced that vaccines had been successful in eradicating smallpox from the world. For the first time in history, man had eradicated a deadly disease.


Victory over rabies
Rabies, the Latin word for "madness," is a severe, acute viral infection of the central nervous system and is one of the most terrifying diseases known to man. All warm-blooded animals, including humans, are susceptible to rabies. It can be transmitted by the bite of a rabid animal or its saliva being introduced into a fresh scratch or similar skin break; it is rarely spread by other routes.

The incubation period, after exposure to a rabid animal, can be as little as six days or as long as one year. The symptoms include changes in attitude and personality, restlessness, abnormal sensation around the area of exposure, fever and loss of appetite. In extreme cases, severe and painful throat spasms occur when the victim tries to swallow or even sees liquids. This fear of water is what gives the disease its common name, "hydrophobia."


Rabies is incurable if it attacks the brain before preventive inoculation. The victim could die from cardiac or respiratory failure. Diagnosis is possible only through autopsy.A vaccine to combat rabies was discovered in 1884 by Louis Pasteur, the great French bacteriologist.


Louis Pasteur first came into the limelight when the silk industry faced a crisis due to diseased eggs. He showed the farmers how they could use a microscope to detect the diseased eggs. These eggs were then destroyed and the disease eliminated in the silkworm nurseries. At this point of time, Pasteur's mind was busy working on his next great theoretical advance - the idea that many diseases in animals and man were the result of germs (harmful microbes), which enter the body and multiply there.

Though honored by the French government with the Legion of Honor, much of the medical profession still resisted his ideas. The older doctors were reluctant to accept his thinking on germs and vaccination. Others resented medical research being conducted by someone whose training was in chemistry, not medicine.


Undeterred by this opposition, Pasteur moved on to the next, and perhaps greatest, step - diseases in humans. In 1882, he began studying rabies. This deadly disease is contracted by being bitten by an infected animal, usually a dog or wolf. Pasteur began his experiments using animals. Previous vaccination work had required that the vaccine be given prior to exposure to the disease. During his research, Pasteur began to give the rabies vaccine to be given after the bite had occurred. He realized that only those who had been bitten by a rabid animal needed to be treated.


In 1885, a small boy who had been bitten by a rabid dog was brought to Pasteur. Although he was not yet sure whether the treatment would work on humans, Pasteur knew the boy would die without the vaccine. After several tense weeks of treatment on the boy, it was clear that the rabies vaccine was a success. In 1888, the Pasteur Institute was established in Paris to continue the fight against diseases. Pasteur is generally recognized today as having made 'the greatest contribution of any one man to the saving of human lives'.


Fighting polio
Half a century earlier, summer was a time of fear for parents in the US. Every summer, thousands of children faced the threat of polio infection. Caused by a virus that destroys nerve cells in the body, victims of polio can become paralyzed and lose the function of their arms or legs. If polio infects the lungs, victims can't breathe without the help of machines.


It was in 1955 that a miracle of sorts happened. Scientists announced that a safe and reliable vaccine for polio had been developed and attributed it to Jonas Salk. Salk's vaccine worked-and it was safe. For the first time, doctors had a way to keep people from ever getting polio. But Salk did not become an international hero, overnight. Here's his story…


1939 - Salk received an M.D. from New York University 
- Appointed assistant professor of epidemiology at the University of Michigan. 
1947 - Became head of the virus research laboratory at the University of Pittsburgh 
1949-54 - Research professor (later Director) of bacteriology professor of preventive medicine 
1957-63 - Professor of experimental medicine 
In 1963 Salk became fellow and director of the Institute for Biological Studies in San Diego, Calif., later called the Salk Institute. Salk also conducted research into the treatment of acquired immune deficiency syndrome (AIDS).


Born in New York City in 1914, to Russian Jewish parents, Salk was encouraged to study and was the first member of the family to go to college. Fascinated by the study of medicines, he was still a student when he began thinking about vaccines.In medical school, he was taught that it was impossible to make a safe vaccine against diseases caused by viruses. To add to the woes of the medical world, the vaccine itself could give people the disease.


Fortunately, like all great scientists, Salk was curious. Instead of accepting what others said, he decided to test the truth for himself. His curiosity led to one of the biggest breakthroughs in the history of medicine. First, he helped to develop a vaccine that worked against the flu virus and was able to create a vaccine against polio after years of research. Salk's work in the 1940s on an anti-influenza vaccine led him and his colleagues to develop an inactivated vaccine against polio in 1952. After successful wide-scale testing in 1954, the vaccine was distributed nationally and greatly reduced the disease. In the mid-1950s American virologist Albert Sabin developed an oral, attenuated (live) vaccine, which along with Salk's discovery brought polio under control.