| Viral hepatitis is a very common infectious disease | | | | Researchers later concluded that antigen Aa was |
| responsible for causing more than 1.5 million annual | | | | actually a component part of the virus identified to |
| deaths among afflicted patients. Despite the fact | | | | cause hepatitis B. |
| that extensive data reports on viral hepatitis have | | | | The findings determined medical scientists to take |
| been first established at the beginning of the 20th | | | | additional measures in preventing the occurrence of |
| century, the causes of the disease remained | | | | hepatitis among the population. By testing blood |
| unknown until the 1940s, when the implication of a | | | | transfusions for the presence of the causative virus, |
| new virus in triggering the disease was first revealed. | | | | scientists hoped to reduce the risks of transmitting |
| Performing additional research on hepatitis, virologists | | | | hepatitis from one individual to another. The method |
| have later discovered two major distinctive types of | | | | used to detect the presence of the virus in the blood |
| hepatitis: hepatitis type A and hepatitis type B. | | | | was given the name of radioimmunoassay. In |
| Concerned by the increasing numbers of hepatitis | | | | present, this technique is still used to test the |
| cases due to blood transfusions, medical scientists | | | | integrity and safety of blood transfusions and other |
| have conducted a series of more elaborate medical | | | | blood products. Appreciated for its efficiency and |
| investigations in order to identify conclusive facts | | | | reliability, radioimmunoassay is the predecessor of |
| regarding the occurrence and progression of hepatitis. | | | | today's modern techniques used in blood screening. |
| Intrigued by the fact that increasingly larger numbers | | | | Another breakthrough consisted in finding an |
| of persons who received blood transfusions | | | | effective vaccine against hepatitis. For the first time |
| experienced symptoms such as high fever, chills and | | | | in history, the main curative agent used in creating |
| skin rashes, doctors decided to carefully analyze a | | | | the vaccine was actually a modified strain of the |
| series of immune reactions to foreign proteins in | | | | causative virus. By altering the virus in the laboratory |
| blood samples taken from such persons in order to | | | | and introducing it in a vaccine, virologists were able to |
| reveal the exact sources of their symptoms. After | | | | stimulate an immune reaction to that particular virus in |
| comparing the immune reactions of the persons who | | | | the human body. A few years later, the ongoing |
| had been administered blood transfusions with those | | | | research conducted on hepatitis led to another crucial |
| of people in good health, medical scientists were able | | | | discovery: the HCV - hepatitis C virus. Short after, |
| to reveal a type of protein that rarely reacted with | | | | medical scientists came up with efficient vaccines for |
| antibodies produced by the immune system. | | | | all existing hepatitis virus types: A, B and C. |
| Due to the fact that the analyzed immune reaction | | | | Over a period of only a few decades, doctors |
| was extremely rare, medical scientists concluded that | | | | discovered valuable facts on hepatitis, as well as |
| it wasn't caused by genetic particularities in the | | | | efficient methods of preventing its transmission. |
| human blood, but by a certain type of infectious | | | | Thanks to the remarkable findings of several pioneer |
| agent. The discovered infectious agent later received | | | | virologists and biologists, medical science was |
| the name of antigen Aa. After continuing their | | | | revolutionized and the mystery around many |
| research on blood proteins, doctors discovered a | | | | different viral infectious diseases was finally unveiled. |
| correlation between antigen Aa and hepatitis. | | | | |