All we heard nowadays is Vaccination. But do we know what happens to our body once we are vaccinated?

Vociferous Writers
3 min readJun 24, 2021


I guess you all are safe and healthy during this critical period of the COVID-19 pandemic. A solution to this pandemic is vaccination. But we have observed certain side effects or severe illness after getting a vaccination. Let us know from a medical point of view, what happens to our bodies once we are vaccinated and how does it prevent us to get affected by the disease.

What is the vaccine?

The vaccine contains weakened or inactive parts of a particular organism that triggers an immune response in the body. Newer vaccines contain the blueprint for producing antigens rather than the antigen itself.

Body’s natural defence against infection:-

To understand how vaccines work we need to first look at how the body fights natural disease. When any pathogen such as bacteria or virus invades the body and multiplies, this invasion causes an infection which leads to illness. The immune system uses many tools to fight the infection such as RBCs and WBCs. white cells contain primarily macrophages, T Lymphocytes and B lymphocytes:

MACROPHAGES: These cells swallow up and digest pathogens and dead cells and leaves behind parts of invading organisms called antigens. The body identifies it and stimulates the formation of antibodies

T LPHOCYTESYM: T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. They attack the cells in the body that are already infected.

B LYMPHOCYTES: These lymphocyte cells produce antibodies that attack antigens that are left behind by macrophages.

When the first-time body encounters any pathogen it takes several days to get over that infection through this antigen-antibody reaction of the immune system. After the infection, the body keeps few T cells as memory cells to remember how to protect the body against that particular pathogen. When that pathogen enters the body again the B cells produce antibodies to attack them.

Process after taking vaccine in the body:-

  • Vaccine imitates the same effects of infection caused by a particular pathogen. It causes the immune system to produce Lymphocytes and antibodies. sometimes after getting the vaccine the imitation can cause minor symptoms such as fever which are normal and expected as the body builds immunity.
  • Once the effect is over the body is left with a supply of memory T cells as well as B cells that will remember how to fight that disease in future.
  • However, it typically takes few days for the body to produce T lymphocytes and B lymphocytes after vaccination.
  • Therefore it is possible that a person infected with a disease before or after vaccination could develop symptoms and can get a disease because the vaccine does not have enough time to develop antibodies.

Written by: Mansi Soni(Instagram: @mansi.s22)
Vociferous Writers (Instagram: @vociferouswriters)