What is a vaccine?
In simple words, a vaccine is a suspension of ■■■■ or weakened microorganisms that is given to a subject to produce immunity of disease that the microorganisms are responsible for.
The vaccine can be made up of weakened or inactive viruses; it may even contain a part of the disease-causing bacteria.
The first vaccine was made by Edward Jenner during the era of smallpox. In the 18th century, smallpox had spread widely and Edward was fascinated how a person who suffered from cowpox could not get infected by smallpox when it was exposed to it.
Types of vaccines
The main challenge faced during the making of a vaccine is that it shouldn’t be that weak that it doesn’t produce any immunity nor strong enough to put a person’s health in danger. That’s why different ways are used to make vaccines
- Weak Virus - In it, a weak virus is injected into the body. A weak virus cannot reproduce properly, the virus usually causes harm by reproducing itself many times. The virus used in vaccines reproduces only a few times due to less reproduction; they don’t cause the disease but they do make the body produce memory B cells that protect the body against diseases in the future. This vaccine is usually for a lifetime but it can’t be given to people with a weak immune system.
- Inactive Virus-Vaccine made up of inactive virus is made by inactivating or killing the virus in that way it doesn’t reproduce at all. When this type of vaccine is given, the body still sees the virus as a threat and ready itself for the battle. The benefit of this type of vaccine is that it can be given to people with a weak immune system although it has to be given several times to induce immunity. Polio Vaccines are made this way
- Part of virus or bacteria-Some vaccines are made up a part of the virus or bacteria or the toxins they release and inactivating them through chemicals
Vaccines effectiveness :
Vaccines are the main reason mortality rate greatly decreased in the world before vaccines deadly diseases and plagues killed millions of people. The economy of the world also suffered greatly due to it. For example, smallpox killed around 300 million around the world and now thanks to vaccines it’s almost nonexistent it was also due to vaccines that polio cases fell by 99 percent. It’s not always that effective but it does prevent a population from great damage .Some of the vaccine-preventable diseases are measles, polio, smallpox, hepatitis A, anthrax, influenza, and tuberculosis
Other than introducing immunity in an individual’s body against a particular disease it also proves itself useful at a population level by producing herd immunity .Herd immunity is achieved in a population when a significant number of people of that population are vaccinated. By herd immunity the rate of spread of the pathogen is greatly reduced and that people in the population who are unable to get the vaccine due to a reason or two also stay safe.
Adverse effects of the vaccines that have been reported are vomiting , brain damage, and seizures and it is also linked to health disorders such as autism although the probability of having these types of side effects from vaccines is very low .