Immunization started hundreds of years ago. It has helped protect people from deadly diseases like COVID-19, tetanus, polio, smallpox and flu. Scientists conduct experiments and develop vaccines for survival and to live longer. Thus, immunization is no doubt essential in human life.
The world has witnessed how the first vaccines saved many lives and for two centuries, new vaccines have been developed to continue to increase the quality of life. The World Health Organization (WHO) celebrates World Immunization Week every last week of April to highlight the importance of vaccines and how immunization protects people from vaccine-preventable diseases.
This photograph taken on December 2, 2021, shows a sign of the the World Health Organization (WHO) next to theirs headquarters, in Geneva.
History of Vaccines
According to the web page, The History of Vaccines, the story of immunization did not start with the first development of the first vaccine. Instead, it started with the long history of infectious diseases in humans and with the early uses of smallpox material with an aim to provide immunization.
Documents reported that the Chinese first started smallpox vaccination as early as 1,000 CE. It was also practiced in Africa and Turkey before it spread to the Americas and Europe.
Through these previous models, Edward Jenner's innovation started. By 1796, the first smallpox vaccine was created and since then, the use of vaccines quickly spread until 200 years later. Vaccination is still used and has led to the eradication of many deadly diseases, including smallpox.
Almost a century later, in 1885, Louis Pasteur made the next impact on human diseases after discovering bacteriology. Vaccine developments soon followed that resulted in anti-toxins and vaccines against tetanus, cholera, plagues, typhoid, tuberculosis, and other deadly diseases in the 1930s.
During the 20th century, vaccine research and development further advanced as scientists started growing viruses in the lab for rapid discoveries and innovations, like creating the vaccines for polio, measles, mumps, and rubella. Vaccine development has since improved with some manufacturers using mRNA and other new technologies.
Ingredients and Phases of Vaccine Development
Boosters contain tiny fragments of the bacteria or virus it aims to kill. But they also contain other ingredients to keep them safe and effective. Each vaccine component serves a specific purpose and is tested during manufacturing.
According to the World Health Organization (WHO), all ingredients are tested for safety. These ingredients include:
- Antigen- The active component that may be the weakened or inactive form of bacteria or virus that generates an immune response or blueprint.
- Preservatives- This component prevents vaccines from being contaminated when the vial is opened so that more than one person could use the vaccine
- Stabilizers - Prevent chemical reactions within the vaccine and keep the components from sticking to the vial.
- Surfactants- Keep all ingredients in the vaccine mixed together and prevent it from settling or clumping. It is also used in other foods, like ice cream.
- Residuals- Tiny amounts of various substances used during the manufacturing or production of vaccines.
- Diluent- Liquid, such as sterile water, used to dilute a vaccine to the correct concentration before use.
- Adjuvant- Some vaccines contain adjuvant, which improves the immune response to the vaccine and stimulates local immune cells.
Vaccine development undergoes screenings and evaluations of which antigen should be used to trigger an immune response. Then, the candidate vaccine is tested on animals to assess its safety and effectiveness. Once it passes the test, human clinical trials follow in three phases for further assessment before it is introduced to the public.
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