Understanding the Corona Virus Vaccine

Getting vaccinated is the best way to protect oneself and others from severe illness or death, especially in the case of the coronavirus. This is in addition to other recommended precautions such as wearing mask, keeping social distance and maintaining a high level of hygiene. K R K Moorthy explains how the vaccine works and the possible side effects.

- K R K Moorthy

To understand how coronavirus vaccines work, we must first know how our bodies fight illness. Pathogens are disease-causing organisms – bacterium, virus, parasite or fungus that invade the body and multiply. When a pathogen infects the body and the person gets sick, our body’s defences, called the immune system, are triggered and the pathogen is attacked and destroyed. The subpart of the pathogen that causes the formation of antibodies is called an antigen. We have thousands of antibodies in our bodies. When the human body is exposed to an antigen for the first time it takes time to produce antibodies specific to that antigen.

If the body is exposed to the same pathogen more than once the antibody response is much faster and more effective than the first time because the memory cells are ready to pump out the antibodies against that antigen. This is the basis for developing vaccines. Vaccines help to develop immunity without getting sick. They are made from the same germs or parts of them that cause the disease. But the germs are either killed or attenuated i.e. weakened so that don’t make the person sick. When these weakened or killed germs are introduced into the body, usually by injection, the immune system reacts the same way as it would if it were invaded by the disease.