Let's talk vaccines: ᴴᵉʳᵈ ᴵᵐᵐᵘⁿⁱᵗʸ

Herd immunity occurs when a large portion of a community becomes immune to a disease, making the spread of disease from person to person unlikely. As a result, the whole community becomes protected — not just those who are immune.

Often, a percentage of the population must be capable of getting a disease in order for it to spread. This is called a threshold proportion. If the proportion of the population that is immune to the disease is greater than this threshold, the spread of the disease will decline. This is known as the herd immunity threshold.

What percentage of a community needs to be immune in order to achieve herd immunity? It varies from disease to disease. The more contagious a disease is, the greater the proportion of the population that needs to be immune to the disease to stop its spread. For example, the measles is a highly contagious illness. It's estimated that 94% of the population must be immune to interrupt the chain of transmission.

There are two main paths to herd immunity — infection and vaccines.

𝙽𝚊𝚝𝚞𝚛𝚊𝚕 𝚒𝚗𝚏𝚎𝚌𝚝𝚒𝚘𝚗

Herd immunity can be reached when enough people in the population have recovered from a disease and have developed protective antibodies against future infection.

However, there are some major problems with relying on community infection to create herd immunity: reinfection and health impact.

𝚅𝚊𝚌𝚌𝚒𝚗𝚎𝚜

Herd immunity also can be reached when enough people have been vaccinated against a disease and have developed protective antibodies against future infection. Unlike the natural infection method, vaccines create immunity without causing illness or resulting complications.

Herd immunity makes it possible to protect the population from a disease, including those who can't be vaccinated, such as newborns or those who have compromised immune systems.

Herd immunity, or community immunity, as it’s sometimes called, is a powerful public health tool. By ensuring those who can be vaccinated do get vaccinated we can achieve herd immunity and prevent the illness and suffering that comes from the spread of infectious diseases.

{You can find all the sources I used by clicking here.}