What is herd immunity and how does it relate to COVID-19?

Herd immunity, also known as population immunity, is a concept in epidemiology that occurs when a large portion of a population becomes immune to a disease, either through vaccination or previous infection. When a sufficient portion of the population is immune, the spread of the disease becomes unlikely, even among individuals who are not immune. This helps protect those who cannot be vaccinated, such as infants or individuals with certain medical conditions.

Regarding COVID-19, achieving herd immunity through vaccination is one of the main goals of the vaccination campaign worldwide. The percentage of the population that needs to be vaccinated to achieve herd immunity for COVID-19 is currently not known with certainty, as it depends on various factors such as the transmissibility of the virus and the effectiveness of the vaccines against new variants. However, estimates range from 70% to 90% of the population needing to be immune to reach herd immunity for COVID-19.

It is important to note that achieving herd immunity solely through natural infection is not a safe or effective strategy, as it would lead to a high number of deaths and severe illness. Therefore, vaccination is the safest and most effective way to achieve herd immunity and control the spread of COVID-19.