"All around us, different outside bodies that may be potentially harmful to us exist, and possibly actually can harm us. We call these things 'pathogens'." Pathogens are a virus, bacterium or cell that causes a disease. For example, COVID-19 is a disease caused by the coronavirus pathogen.
"For a great part of human history, these diseases caused great suffering amongst all communities."Notable periods of extreme pandemics include the Black Death, which occurred in the medieval period. Medicine was basic or even nonexistent.
"Fortunately, for humanity, Edward Jenner who was an English physician, founded vaccinology after he immunized a 13 year old in 1796. In 1798, the first smallpox vaccine was developed." Because of this advancement, smallpox was declared extinct by the WHO in 1980.
"Vaccines inject a dead, inactivated or weakened pathogen into the body, and are identified through their antigens. The immune system fights against this easily, and memorizes how to fight the pathogen if it ever encounters it again." Vaccines rely on the third line of defense, where B-Cells bind to the pathogen and create memory cells that serve as a reminder to the body's defense.
"By creating this memory, you, through your immune system, become immune to the pathogen. For most of human history, this has not been the case, but we're now able to eliminate deadly diseases through this method of tricking your immune system to remember a pathogen."
"So remember, go get vaccinated! Vaccination has saved millions of lives, and is one of humanity's greatest weapons against the world's diseases. Vaccines are needed whether you stay in the same town or travel the world, saving lives with a little jab with a needle."