There is no doubt that in an age as convulsive as today, when a pandemic has ravaged the speeches of all experts, the use of vaccination and vaccines is needed more than ever.
I find it hard to believe how many people speak unstopperedly who are against vaccines. It’s very easy to be on your comfortable sofa at home and say that everyone does things wrong, without bringing any ideas. No one asks you for advice, except if you’ve studied enough to understand that a virus is an extremely complex organism and needs to be thoroughly studied to find its weaknesses. I’m sorry to say, but your negative messages are useless and won’t solve the current problem.
Along with personal hygiene and antibiotic use, vaccination is one of the most life-saving practices. I don’t say it, the numbers say so. You don’t believe the numbers either? It’s not said by a tribu healer or a charlatan who only sells smoke without proof of anything.
Years ago infections killed the population. Egyptian papyrus such as the Babylonian Epic of Gilgamesh in 2,000 BC is known where there is written evidence of plagues. In most cases they were attributed to them teluric origin, i.e. divine punishments. Also in the 430 BC there was a plague epidemic in Athens of which Tucidides said “Noonesuffers from the disease twice, and if that happens, the second attack is neverfatal.”
Historical perspective on vaccines
The World Health Organization (WHO) has recognized it as a historical fact on 9 December 1978. The end and eradication of smallpox in the world was declared. Five months later, on 8 May 1980, the WHO assembly officially declared eradicated and that “theworld and all its peoples have escaped smallpox.”.
Smallpox was a serious, contagious infectious disease with a high risk of death, caused by the Variola virus. The 10th century has been known to inhale dry scabs from smallpox-infected people in China and India to prevent infection. This resulted in variolization, i.e. a prophylactic technique so that a person does not become infected with smallpox. In Turkey, pus of vesicles were inoculated to girls in order to “preserve beauty”.
Europe was unaffe about this practice and caused a major epidemic in 1721. Lady Mary Montagy observed variolization in Turkey and convinces the royal family to variolize the princes. This actual experiment occurred in 1722 and prevented them from spreading.
The arrival of immunology
In the eighteenth century Edward Jenner researched human smallpox and with his work we can talk that he was the father of immunology. Notice that a cow milker named Sarah Nelmes had hand postulates because his smallpox wounds had been infected.
Based on a hypothesis, smallpox vaccine protects against human smallpox. What he did was inoculate smallpox “vaccine” to a healthy child named Philips after getting pus from the farmer. Then it inoculates human smallpox several times to the child. Human smallpox doesn’t infect the child. In conclusion, somehow injecting the smallpox vaccine into the child made the child immune to human smallpox.
Research in the 19th century
In the 19th century there was significant progress in infections carried out by scientists who have gone down in history. Among these scientists were Koch (1843–1910) and Pasteur (1822–1895). By using the first microscopes you could see that there are organisms so tiny that they went unnoticed by the human eye. These microorganisms were linked to diseases and became pathogens.
Koch discovered the causal agents of cholera, anthrax and tuberculosis. He also discovered that insects transmitted trypanosomiasis and was created by Koch’s postulators. These postulates are:
- The pathogen must be present in sick animals and absent in healthy animals. Therefore, the disease is caused by a pathogen.
- The agent must be grown in a pure arsenic culture isolated from the body of the animal. That is, the pathogen must be located in the fluids of the sick animal.
- The isolated agent in an axenic culture should cause the disease in a susceptible animal when inoculated. Therefore, a healthy animal is infected by the pathogen.
- The agent must be isolated again from lesions produced in experimental animals and be exactly the same as the originally isolated one.
Pasteur was the discoverer of fermentation and was the first to say that there was no spontaneous generation and to disprove that hypothesis. That is, there are no life forms (animal and plant) that arise spontaneously (out of nowhere) from organic matter, inorganic matter or combination there.
In this way, pathogens that threatened animals or plants began to be known. Viruses, bacteria, fungi, parasites etc. were discovered. In the twentieth century, new techniques such as knowledge of genes and proteins were used and the problems caused by pathogens were studied.
Vaccines in the 20th and 21st century
There are different types of vaccines that we can organize by:
- Attenuated vaccines. The virus weakens as it passes through animal or human cells, until the genome mutates and cannot cause the disease. Examples of these vaccines are:
- BCG (Bacillus Calmette-Guérin) discovered in 1927.
- Yellow fever discovered in 1935.
- Smallpox discovered in 1950.
- Oral polio in 1961.
- Measles in 1963.
- Papers in 1967.
- Rubella in 1969.
- Inactivated vaccines. Inactivated virus with formaldehyde or heat. Examples of these vaccines are:
- Tosferina in 1926.
- Flu in 1936.
- Polio (salk) in 1955.
- Polio improved in 1978.
- Rage in 1980.
- Hepatitis A in 1994.
- Toxoid fractions. These include:
- Diphtheria in 1923.
- Let’s have it in 1927.
- Hepatitis B in 1979.
- Encephalitis in 1980.
- Polysaccharides. These include:
- Meningo in 1972.
- Neumococo 14-v in 1977.
- Meningo 4v in 1980.
- Neumococo 23-v in 1983.
- Haemop b in 1984.
- Haemop c in 1987.
- MeningC in 2000.
- Neumo 7v in 2000.
We can also classify vaccines according to which microorganisms they use. In this case we talk about:
- Vaccines that use dead microorganisms. These include Bordetella pertusis, Yersinia pestis, Vibrio cholerae,hepatitis A, influenza, poliovirus and rabies.
- Vaccines that use attenuated microorganisms. They are made with passes by animals or in cell cultures. Mycobacterium tuberculosis, Salmonella typhi, measles, poliovirus, rubella, mumps, varizela-zoster are found.
- Vaccines that use subunits of microorganisms. Salmonella typhi, Bordetella pertussis, Clostridium tetani, Corynebacterium diphteriae are used..
- Vaccines that use subunits obtained by genetic engineering. Such is the case of Hepatitis B, Bordetella pertussis, Vibrio cholerae and Borrelia burgdorferi.
The Sars-cov-2 pandemic
Coronavirus disease 2019 (COVID-19) has become a real human tragedy both because of its health impact and its economic impact. Governments around the world have taken measures to confine, block travel and borders and take action to mitigate the morbidity and mortality of the virus.
As of today, there is no vaccine to prevent the human species from contracting the disease. This leads to a global race to get a vaccine as soon as possible. There is unprecedented work around the world for the research and development of an effective and safe vaccine.
Technology platforms have developed vaccine candidates in a matter of days, weeks or months and there are currently 212 vaccine candidates available as of November 12 (who candidate vaccines source). Out of that total 48 are candidates for vaccine in clinical evaluation and 164 are candidates for vaccines in preclynic evaluation.
- Apuntes máster Biotecnología Avanza.