Chasing after the vaccine

The infectious diseases that more people have killed throughout history are the black plague, caused by a bacterium (Yersinia pestis) and smallpox, caused by a virus (Variola major). Smallpox is believed to have emerged in the Neolithic revolution about 10,000 years ago. Evidence has been found in Egyptian mummies from the 3rd century BC. Over the centuries it has caused numerous epidemics that decimated the population, especially during the Middle Ages. With the arrival of Europeans in America, it is believed that it killed 90% of the indigenous population. In the 19th century, the demographic increase in the world population made it easier to kill 400,000 people a day. And during the 20th century, with the vaccine already discovered, it still killed 300 million more people. It mainly infects the oral cavity and esophagus, but it ends up passing into the blood and it also produces a very spectacular skin rash with purulent macules all over the body. His vaccine was the first to be discovered, in 1796, thanks to the observant ability of the English rural doctor Edward Jenner. At that time it was known that milkmaids were slightly infected with cowpox, when they milked cows, and were subsequently immunized from the deadly human smallpox. Jenner scraped pus from the macules of a milkmaid and inoculated it into a boy, who had a fever for a few days but soon recovered. After a couple of months, Jenner inoculated the human smallpox virus into the same boy, but this time he did not develop the disease. This discovery spread throughout the world, and smallpox vaccination saved millions of lives. Later, the also scientist Louis Pasteur proposed, in homage to Jenner, that this type of medicine be called a “vaccine” because it originated in the cow.
Vaccines are currently based on the stimulation of natural immunity through the inoculation of deactivated, attenuated pathogenic microorganisms, their toxins or their structural subunits. Developing a vaccine requires several phases: computational, in vitro, in vivo in laboratory animals, often transgenic, and clinical trials of a few people, hundreds and thousands of people, before being able to apply massively. The process is, therefore, very costly in time and resources and it is estimated that in the case of the coronavirus it will not arrive for another 15-18 months. That is why, meanwhile, other strategies such as antiviral drugs, which decrease the viral load of infected people and, therefore, reduce their contagion ability, are being studied.