The Origins Of Vaccinations

A vaccine is a mechanism to trick our immune system into producing antibodies against a specific virus by introducing a nonharmful part of this virus to the body.

You most likely have been infected with chickenpox before. You also know that you are never infected again if you are infected once.

This is because your body has developed antibodies against this infection.

The same mechanism happens with the vaccine!

Hundreds of years ago, we have recognized that some diseases never reinfect a person after recovery.

Smallpox was the first virus we tried to prevent by intentionally inoculating ourselves with a nonharmful part of the virus.

This happened when the physician Edward Jenner inoculated a kid and prevented him from getting smallpox.

Edward Jenner used a lancet to scratch some infected material from a woman with cowpox (a virus similar to smallpox) under the boy's skin, which is somewhat unethical, but, believe it or not, it has changed our world!

In that way, the child's body has been trained to attack smallpox without actually being infected with it.

How Do These Vaccines work?

So with all of these things in mind, there is one main question that arises - How do vaccines work, exactly?

Let’s find out!

Live Attenuated Vaccines

Most vaccines are given by injection. What is injected depends on the specific vaccine. Some vaccines are called live attenuated, meaning that we inject a weakened version of the virus that causes no harm.

Once inside our body, the immune system recognizes this naive virus as foreign and starts mounting an immune attack against it.

This will make our body develop antibodies that are stored. When we are infected with the actual virus, these previously made antibodies start attacking the harmful virus.

Examples of live-attenuated vaccines include MMR, varicella, yellow fever, rotavirus, influenza (intranasal), smallpox, and adenovirus.

Inactivated Vaccines

This type is different from live attenuated ones. In inactivated, instead of injecting a weakened version, we are injecting only a part of the virus.

In other words, instead of killing it then injecting it, we cut it into pieces and inject one of them into the body.

Occasionally, we need to create vaccines against bacteria. We can use inactivated vaccines in this case.

We obtain the toxins produced by these bacteria, inactivate them, and inject them into the body.

Therefore, instead of injecting the whole bacteria, we only injected part of it, which is the toxin.

What About The COVID-19 Vaccine?

There are 2 mechanisms of vaccines not discussed above. They are the ways by which all the COVID-19 vaccines work. It is our first time ever using these techniques.

The first mechanism is the mRNA vaccine ( Pfizer-BioNTech COVID-19 and Moderna COVID-19 ) and viral vector vaccines ( Johnson & Johnson vaccine and AstraZeneca).

mRNA vaccines are somewhat complex. They work by injecting the virus's genetic code (instead of attenuated virus or part of it). The genetic code of the virus is the mRNA.

Our cells receive the genetic material and start creating the viral proteins. Then our immune system attacks these proteins, leading to the development of antibodies.

The viral vectors vaccine is somewhat similar. However, in that case, we inject a nonrelated, dead virus with the genetic code of the desired virus.

This naive virus will deliver the genetic material of the desired virus to our cells. The cells start creating the viral proteins. The immune system then attacks these proteins.

Conclusion

Listen, vaccines have changed the world. Without them, the human would become extinct. Hundreds of years ago, they saved us from deadly diseases like smallpox, rabies, and polio.

Today, they are saving us from another contagious, deadly disease: COVID-19.

Who knows what might happen in the future? Maybe another pandemic with another virus and vaccine?

If you have taken the COVID-19 vaccine, tell us about your experience in the comments and whether it really could protect you or not.