Difference Between Herd and Ring Immunity

The key difference between herd and ring immunity is that herd immunity develops when a significant portion of a population is vaccinated while ring immunity develops when all susceptible individuals in a prescribed area around an outbreak of an infectious disease are vaccinated.

Vaccination develops immunity in the body. Upon vaccination, people develop immunity against infectious agents such as viruses, bacteria and fungi. If the infectious agent comes back very stronger, the body is ready to fight it off. Herd vaccination and ring vaccination are two types of vaccinations. In herd vaccination, a significant portion of a population is vaccinated. Meanwhile, in a ring vaccination, all susceptible individuals in a prescribed area around an outbreak of an infectious disease are vaccinated.

1. Overview and Key Difference
2. What is Herd Immunity
3. What is Ring Immunity
4. Similarities Between Herd and Ring Immunity
5. Side by Side Comparison – Herd vs Ring Immunity in Tabular Form
6. Summary

What is Herd Immunity?

Herd immunity is a form of immunity that occurs after herd vaccination. Herd vaccination refers to the vaccination of a significant portion of a population. It provides a measure of protection for individuals who do not have immunity against that particular infectious disease. In herd vaccination, a high percentage of the population is protected through vaccination. Therefore, it is difficult for a disease to spread since there is a few susceptible individuals remaining in the population. Due to herd immunity, the community is protected as enough people are immunized. Hence, it is an effective way of stopping diseases from spreading in the community. Hence, there is less likelihood for immune-compromised people to come into contact with the disease.

Difference Between Herd and Ring Immunity

Figure 01: Herd Vaccination

What is Ring Immunity?

Ring immunity is a form of immunity that occurs after ring vaccination. Ring vaccination is a type of vaccination in which all susceptible individuals in a prescribed area of an outbreak of an infectious disease are vaccinated. Therefore, in ring vaccination, individuals those who are most likely to be infected are vaccinated. Generally, the ring includes individuals of the family, friends and neighbours. Thus, it includes several layers of contacted people. Ring vaccination requires contact tracing in order to figure out the people who are most likely to be infected. It is a strategy to prevent the spreading of an infectious disease forming a buffer of immune individuals. Moreover, it facilitates the monitoring of a ring of people around each infected individual. Ring vaccination is used to eradicate smallpox. Moreover, it was used when the Ebola virus pandemic occurred in Africa.

What are the Similarities Between Herd and Ring Immunity?

Herd and ring immunity are two types of immunity development in individuals.
They occur after vaccination.
Both strategies prevent the spreading of an infectious disease.

What is the Difference Between Herd and Ring Immunity?

Herd immunity is a form of immunity that develops when a significant portion of a population is vaccinated. On the other hand, ring immunity is a form of immunity that occurs after vaccination of only those who are most likely to be infected. Thus, this is the key difference between herd and ring immunity. Moreover, contact tracing is not required in herd vaccination while contact tracing is required in ring vaccination.

Below is a summary tabulation of the difference between herd and ring immunity.

Summary – Herd vs Ring Immunity

Herd immunity and ring immunity are two forms of immunity developing after herd vaccination and ring vaccination, respectively. Herd vaccination refers to the vaccination of enough people in the community. Therefore, a significant or sufficient portion of the population is vaccinated and protected. Ring vaccination refers to the vaccination of individuals those who are most likely to be infected. Family, friends and neighbours are included in the ring. Hence, ring immunity develops in direct contact of infected individuals, and contacts of those contacts. So, this summarizes the difference between herd and ring immunity.

Reference:

1. “Herd Immunity.” Wikipedia, Wikimedia Foundation, 7 Oct. 2020, Available here.
2. “Ring Vaccination.” Centers for Disease Control and Prevention, 2 Dec. 2019, Available here.