Herd immunity, also known as herd immunity, community immunity, is a slogan that is often used in the context of vaccination, as well as in the context of the disease caused by the SARS-CoV-2 coronavirus. What is herd immunity? What is the herd immunity threshold and what is its significance for the elimination of infections?
Oherd immunity(herd immunity) a lot has been said recently, especially in the context of COVID-19. Epidemiologists estimate that creating herd immunity in society would help to tackle the COVID-19 pandemic more quickly. So it's worth knowing what this phenomenon is all about and how you can achieve herd immunity.
What is herd immunity (herd immunity)?
Herd immunity, population immunity, herd immunity, herd immunity, group immunity - these are terms that define the same phenomenon. Basically speaking, it is protecting people who are not immune to the disease - and this protection can be obtained by vaccinating as many other people as possible.
The higher the percentage of people who are resistant to a given disease, the lower the risk that someone who is not immune will contract it. It is important to know that herd immunity (herd immunity) only applies to diseases that are transmitted from person to person, not via animals. Therefore, one can develop herd immunity to e.g. measles or whooping cough, but not to rabies or tick-borne encephalitis.
What is the herd immunity threshold?
The herd immunity threshold is the so-called "Safety threshold": it is the number of people (their percentage) immunized in a given population, after which the number of new infections starts to decline. Typically, the herd immunity threshold is 90-95%. population, however, it all depends on the disease. For example, in the case of mumps, the herd immunity threshold is estimated at 75-86%. (this is the number of people in a given population that must be immune to mumps to avoid widespread infection), the safety threshold for whooping cough is about 94%, for rubella and diphtheria - 83-86%, and for measles - 95%.
Why is herd immunity (herd immunity) important?
Immunitycollective allows to protect against disease not only people vaccinated against a given disease, but also those who, for various reasons, cannot be vaccinated - e.g. age is a contraindication, an anaphylactic reaction to vaccination or chronic diseases.
It also allows to reduce the presence of a given pathogen (virus or bacteria) in the environment, and in the case of some infections, to eliminate it completely, protecting the population against dangerous infectious diseases.