flokkimunitet

Flokkimunitet, also known as herd immunity or community immunity, is a form of indirect protection from 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 previous infection. When a sufficiently high proportion of the population is immune, the chains of infection are broken, making it difficult for the disease to spread.

The threshold for herd immunity varies depending on the contagiousness of the disease. Highly contagious diseases like measles require a very high percentage of immunity, often above 90%, to achieve herd immunity. Less contagious diseases may require a lower percentage. The concept is crucial in public health strategies for controlling and eradicating infectious diseases.

Herd immunity does not mean that every individual in the population is immune. There will always be a susceptible portion of the population, including infants, the elderly, and individuals with compromised immune systems who cannot be vaccinated or for whom vaccines are less effective. Herd immunity protects these vulnerable individuals by reducing their likelihood of exposure to the pathogen.

Achieving and maintaining herd immunity is a primary goal of widespread vaccination programs. When vaccination rates decline below the herd immunity threshold, outbreaks of preventable diseases can occur. Public health efforts often focus on increasing vaccination coverage to ensure robust community protection.