The term "herd immunity" is widely used but carries a variety of meanings. Some authors use it to describe the proportion immune among individuals in a population. Others use it with reference to a particular threshold proportion of immune individuals that should lead to a decline in incidence of infection. Still others use it to refer to a pattern of immunity that should protect a population f...

Many organisms vary their level of investment in defensive characters. Protective traits may be induced upon exposure to predators or parasites. In a similar way, humans vaccinate in response to threatening epidemics. When most group members defend themselves, epidemics die out quickly because parasites cannot spread. A high level of group (herd) immunity is therefore beneficial to the group. T...

COVID-19 Vaccination, Herd Immunity and The Transition Toward Normalcy: Challenges with Upcoming Sports Events

A population can be immune to epidemics even if not all of its individual members are the disease, so long as sufficiently many - this is traditional notion herd immunity. In smartphone era a single one disease we call "digital immunity", which similarly an emergent characteristic population. This immunity arises because contact-tracing protocols based on capabilities lead highly efficient quar...

Vaccination has been used for the prevention and eradication of communicable diseases such as smallpox, polio, measles. Herd immunity threshold have already conceptualized outbreaks pandemicity these diseases. Coronavirus infectious disease-19 (COVID-19) is second pandemic coronavirus disease 21st century. conducted since December 2020 in an attempt to control pandemic. The morbidity incidence ...

Immunity to the SARS-CoV-2 virus ensures protection against reinfection by this thanks combined action of neutralizing antibodies and T lymphocytes specific viral proteins, in particular Spike protein. It must be distinguished from immune response that healing infection following contamination involves innate immunity, particularly type 1 interferons, which is followed adaptive cellular humoral...