The development of vaccines in the 20th century helped decrease the mortality rate of human beings. Although vaccines don’t guarantee complete protection from an illness or disease, it helps boost the immune system that can slow down the toxins caused by the bacteria in the body.
The English physician Edward Jenner developed the small pox vaccine in 1796. Due to his achievement, he was dubbed as “the father of immunology”. Vaccines contain dead or inactivated microorganisms or its purified product that stimulates the body’s immune system and destroys the bacteria or toxins.
The immune system recognizes foreign agents that attacked the body and destroys it at a later encounter. Its effectiveness can last for a long period until doctors can decide when an adult or child can have another vaccination. Vaccinations can be scheduled yearly or even after every ten years.
The 20th century brought many developments to cure deadly diseases. Some vaccines are still being researched and developed for old and new diseases while some vaccines are being improved. Here is a list of the top 10 deadly diseases that have been discovered and cured in the 20th century.
10. Typhoid Fever
Typhoid fever is a bacterial disease caused by ingestion of contaminated food and water by the feces of an infected person. It contains the bacteria “Salmonella Typhi”. Typhoid fever is believed to have originated in Athens in the year 430-424 BC when a devastating plague hit the city. According to the World Health Organization (WHO), an estimate of 17 million cases of typhoid fever occurs globally. Around 600,000 deaths have been recorded each year. A vaccine was developed in 1896 and then again in 1909, which successfully declined the number of typhoid fever victims who were immunized.
Tetanus is a medical condition caused by infection in the wound by the bacteria Clostridium tetani’s neurotoxin “tetanospasmin”. Its symptoms are spasms in the jaw muslces, neck, back, chest and abdominal muscles; excessive sweating and fever. The first Tetanus vaccine was developed in 1924 by P. Descombay. The bacteria lives in rusty metal and nails. Adults are recommended to receive vaccination every ten years.
Polio is a viral infectious disease acquired through oral-fecal route. The virus transfers when the hands are contaminated by an infected person’s stool. Approximately 95% of the infection shows no symptoms at all. Polio causes muscle weakness and paralysis. The English physician Michael Underwood provided the early description of polio in 1789. The Polio vaccine was developed in the 1950’s, which reduced the number of polio cases worldwide.
7. Pneumococcal Disease
Pneumococcal Disease is caused by the “Streptococcus Pneumonae” bacteria, which can cause pneumonia, sinus infections and meningitis. The bacteria were discovered by U.S. army physician George Sternberg and French chemist Louis Pasteur in 1881. The first Pneumococcal vaccine was used in 1945. The vaccine is recommended for children and adults older than 65 years old.
Pertussis or whooping cough is a respiratory infection caused by “Bordetella Pertussis” infection. It is highly contagious and prevalent among infants and children where symptoms include a high-pitched “whoop” sound. Adults can also get infected and usually have a hacking sound instead of the whooping sound. In 1906, immunologist Jules Bordet and bacteriologist Octave Gengou researched about the bacteria and developed the first vaccine. According to WHO, an estimate of 50 million people are infected worldwide and about 294,000 die annually.
Measles is a viral illness of the respiratory system. It is highly contagious caused by the “Morbillivirus”. Its symptoms resemble a simple cold such as runny nose, red eyes, fever and cough. However, measles is a serious disease and its most distinctive symptoms are the rashes. The Persian physicist Rhazes provided the first scientific description of measles. Maurice Helman, an American microbiologist, developed the first vaccine in in 1963. Risk factors where measles can be acquired are by traveling to places where the disease is endemic, direct contact with persons infected, coughing and sneezing.
Malaria is an infectious disease caused by a mosquito bite. When the female mosquito is infected by the micro-organism “protists” and bites humans or other animals, the parasite attacks the liver to mature and reproduce. Its symptoms include headache, fever, seizures and kidney failure which could cause death. Malaria is treated depending on the severity of the disease. An estimate of 350 million to 500 million people from around the world is infected by Malaria every year. Malaria can be prevented through health education and by using mosquito nets, insecticide and insect repellents to prevent mosquito bites.
3. Invasive H. Flu
Invasive H. Flu is caused by “Haemophilus influenza”, an infectious bacterium that can cause meningitis, pneumonia and blood infection. It was discovered by German bacteriologist Richard Pfeiffer in 1892. It was first mistaken as the cause of influenza. However, Haemophilus influenza still causes a wide range of clinical diseases. The vaccine became available in the 1990’s. However, the “Hib vaccine” is expensive and costs seven times the total cost of tetanus, pertussis, measles, polio and tuberculosis. About 2 to 3 million cases worldwide are associated with the disease.
Diphtheria is a contagious respiratory illness caused by the bacterium “Corynebacterium diphtheria” which affects the nasal cavity, tonsil, pharynx and skin. It was German bacteriologist Friedrich Loeffler who first discovered the illness in 1884 while it was bacteriologist Shibasaburo Kitano and German physiologist Emil von Behring discovered the first cure in 1890. The first real vaccine was introduced in 1913 and the number of deaths declined by 1924. There are about 5,000 deaths from Diphtheria each year according to the WHO.
1. Chicken Pox
Chicken Pox is a highly contagious disease caused by “Varicella-zoster” virus. Its primary symptoms include itchy rash on the body and head while some serious instances can lead to viral pneumonia and encephalitis. The first vaccine was created by Michiaki Takahashi in 1974. Chicken Pox is uncommonly fatal and is more common in adult males, non-immune pregnant women and those with weak immune system.