1 / 6In less than 18 months after it was first detected, the COVID-19 virus has wrecked economies, human lives and healthcare systems across the globe. Researchers have raced against time to develop safe and effective vaccines. According to the World Health Organization (WHO), there are over 50 vaccine candidates in trials and a few have been approved for public use in the fight against COVID-19. Over the past few centuries, vaccines have played a major role in rescuing humanity from some of the deadliest diseases. Vaccination is extremely crucial for infants, children, elderly and those with a weak immune systems. It not only protects the person who contracts a disease, but prevents the spread of the disease. (Image: Reuters)
2 / 6Smallpox | Smallpox was an infectious disease with flu-like symptoms that had no treatment or cure. By the 16th century, it had become a major cause of morbidity and mortality throughout the world. In the 18th century Europe, it was a leading cause of death with an estimated 400,000 victims each year. In 1796, Edward Jenner, an English physician, discovered that immunity to smallpox can be achieved by inoculating a person with a substance from cowpox lesions. Thus, the first modern vaccine was created. The last smallpox outbreak was reported in the UK in 1978. The disease was eradicated globally by 1980. (Image: Reuters)
3 / 6Diphtheria | Diphtheria is a highly contagious disease that spreads by direct contact or through the air. Before the 1980s about a million cases were reported every year. The diphtheria vaccine was first developed in 1923 and its use resulted in over 90 percent reduction in cases globally between 1980 and 2000. In 2015, only about 2,000 cases were reported. As of 2016, about 86 percent of the world population was inoculated. (Image: AP Photo)
4 / 6Tetanus | Tetanus, also called lockjaw, is a bacterial infection that causes muscle spasms which often begin in the jaw and then spread over the rest of the body. The disease accounted for around 780,000 deaths of newborns in 1988. Tetanus antiserum was first developed in 1890, but its protection lasted only a few weeks. The vaccine was finally developed in 1924 after which it was commonly used for soldiers in World War II. The vaccine brought about 95 percent reduction in cases. By 2010, the number of cases fell to about 58,000 globally. Several vaccine combinations such as DTaP and Tdap contain diphtheria, tetanus and pertussis vaccines. (Image: Reuters)
5 / 6Influenza | Influenza vaccines or flu shots protect against infection by influenza viruses. The virus results in 3 to 5 million severe cases every year. It is recommended by WHO for high-risk groups such as children, elderly, pregnant women and health care workers. Vaccination against the disease began in the 1930s. Due to high mutation rate of the virus, a particular vaccine usually provides protection for only a few years. The vaccine is reformulated for specific flu strains every season. (Image: AP Photo)
6 / 6Polio | Polio is a contagious disease caused by the poliovirus. It affects the central nervous system and can result in flaccid paralysis. The virus is usually spread through infected faecal matter. The first successful polio vaccine was created in 1950 by Hilary Koprowski and a few years later by Jonas Salk. The oral polio vaccine which was developed by Albert Sabin came into commercial use in 1961. The global immunization efforts have reduced the number of cases by 99.9 percent. While in 1988 there were an estimated 350,000 cases, in 2001 it was reduced to just 483. Only 175 cases of wild polio were reported in 2019. (Image: Reuters)
