nyájimmunitást

Herd immunity, or "nyájimmunitás" in Hungarian, is a concept describing the indirect protection from an infectious disease that occurs when a large percentage of a population has become immune to an infection, thereby providing a measure of protection for individuals who are not immune. This immunity can be achieved through vaccination or through a prior infection.

The principle behind herd immunity is that when a high proportion of individuals in a population are immune, the chain of infection is broken. This means that the disease is less likely to spread from person to person because there are fewer susceptible individuals available to contract and transmit it. Consequently, even those who are not immune, such as infants, the elderly, or individuals with compromised immune systems, are protected because the disease has a lower probability of reaching them.

The threshold for achieving herd immunity varies depending on the specific infectious disease and its mode of transmission. Highly contagious diseases, like measles, require a very high percentage of the population to be immune to achieve herd immunity, often exceeding 90%. Less contagious diseases may require a lower threshold. Public health strategies often aim to achieve herd immunity through widespread vaccination programs, as this is generally considered a safer and more effective method than relying on natural infection, which can lead to significant illness and death.