Herd immunity

Herd immunity

Subject: Science and Technology

Context: The fourth sero survey conducted across India found that on an average 67.6% of the population has been infected. Also, over 25% of people have been vaccinated with one dose. It is Erroneous to conclude we have attained herd immunity,’ says Dr. Srinath Reddy

Context:

• Herd immunity happens when so many people in a community become immune to an infectious disease that it stops the disease from spreading.

This can happen in two ways:

• Many people contract the disease and in time build up an immune response to it (natural immunity).
• Many people are vaccinated against the disease to achieve immunity.
• When a large percentage of the population becomes immune to a disease, the spread of that disease slows down or stops.
• Many viral and bacterial infections spread from person to person. This chain is broken when most people don’t get or transmit the infection.
• This helps protect people who aren’t vaccinated or who have low functioning immune systems and may develop an infection more easily.