How Does the Herd Immunity Occur?

Subject: Immunology
Pages: 1
Words: 285
Reading time:
2 min

The immune system’s primary task is to protect the body from antigens like germs, poisons, and cancerous cells from invading and damaging them. External protection in the form of skin is the first line of protection; non-specific immune cells are the second line of defense; and the specific immune system, formed of lymphocytes, is the third line of defense (Sun et al., 2020). The innate or non-specific immune response is the initial line of protection. The primary goal of the innate immune response is to stop invading infections from spreading and moving throughout the body (Sun et al., 2020). The adaptive immune response is the second line of defense against invading infections. The adaptive immune response is meant to fight outside infections, but it may sometimes go wrong and harm itself (Sun et al., 2020). The adaptive immune response is not as immediate as the innate immune response, but at the same time, the adaptive immune response, the other hand, has a long-term effect.

Herd immunity occurs when a large percentage of a community is immune to a disease as a consequence of vaccination or previous infection, making disease transmission improbable from person to person (Smith, 2019). Because the illness has few opportunities to spread in society, even unvaccinated persons, such as babies and immunocompromised adults, are granted some protection. The disease’s contagiousness determines herd immunity. To develop herd immunity, diseases that spread readily, such as measles, require a larger number of immune persons in the population (Smith, 2019). The most vulnerable individuals of our population are protected by herd immunity. To reach herd immunity status, mass immunization is required (Smith, 2019). This helps future generations gain immunity and inhibits the spread of hazardous illnesses.


Smith, D. R. (2019). Herd immunity. Veterinary Clinics: Food Animal Practice, 35(3), 593-604.

Sun, L., Wang, X., Saredy, J., Yuan, Z., Yang, X., & Wang, H. (2020). Innate-adaptive immunity interplay and redox regulation in immune response. Redox Biology, 37, 101759.