Herd Immunity
Herd immunity, community immunity, population immunity, or mass immunity is a form of indirect protection from infectious disease. Herd immunity occurs when a large percentage of a population is immune to a specific infection. There are two ways to achieve herd immunity and become immune to the disease: to get infected with this disease, get over and develop protective antibodies against future infection, or to be vaccinated. As a result of herd immunity, the spread of disease decreases, the potential risk of infection for individuals who lack immunity also decreases, and the chain of infection is disrupting.
The greater the percentage of immune individuals in a community is, the larger is the benefit for the society. The probability of further infection is lower and the likelihood to eradicate disease, prevent virus mutation and epidemic appearing are higher. Besides, herd immunity is a crucial way of protecting individuals who cannot become immune for some reason. These are newborns and people who have disruptions in the immune system, immunodeficiency or immunosuppression. But herd immunity applies only to contagious diseases transmitted from one individual to another, not for all infectious. For example, this does not apply to tetanus.
When a high level of herd immunity is achieved, the whole community becomes protected and disease gradually disappears from a population. Otherwise, a contagious disease will continue to spread. The term of herd immunity threshold or threshold proportion is also introduced. Once the percentage of the immune individuals exceeds this threshold, the spread of the disease decreases. But this percentage varies from disease to disease. The more contagious disease is, the greater percentage of the population needs to have immunity to stop the spread of the disease.
Mass immunization contributes to the achievement of herd immunity. Unlike the natural infection method, vaccines create immunity without causing illness or complications. At the same time, the opposition to vaccination has negative consequences for the whole society. It breaks getting herd immunity and allows diseases to persist in and return to the population, causing the outbreak of the disease again and again.
Example 1. Herd Immunity to Different Diseases
Coronavirus COVID-19 is a clear example of a meeting of the society with a new virus and starting of getting herd immunity around the world. But at the moment, there are many issues according to the COVID-19 immunity. It’s not completely clear how long the antibodies are stored in a body of a person who has recovered from COVID-19 and how long he is protected from getting sick again. Moreover, the virus rapidly mutates and there is no guarantee in defense from the mutated virus by means of previously obtained antibodies.
But it is necessary to stop the spread of germs COVID-19 and preventive actions in combination with vaccination will help to get a herd immunity and finally stop the spread of COVID-19. There are also some problems with vaccination. It’s not clear reliably how long it will protect from COVID-19 and its mutated variants. Some people object to getting a COVID-19 vaccine for different reasons including fears about the possible risks because of the lack of knowledge of the disease itself and the vaccine in particular. The made research confirms the effectiveness of vaccines in protecting against severe illness, hospitalization, and death as a result of COVID-19. But further research is also needed. Uneven vaccine spread over the world also affects the speed of vaccination.
Example 2. Medical Virology Diagram - Contact Tracing
ConceptDraw DIAGRAM supplied with Medical Virology solution is the application for designing great-looking infographics and diagrams describing a variety of viruses, their specifics, and conditions of taking a herd immunity. The benefits of using the ready-made design elements and symbols included in solution libraries are obvious. You don't need to pay efforts to create the complex clipart objects, only drag them from the libraries to your illustration.
Example 3. Medical Virology Samples and Libraries in ConceptDraw STORE
The medical virology infographics you see on this page were created in ConceptDraw DIAGRAM software using the Medical Virology Solution and included virology-related pictograms. They successfully demonstrate the solution's capabilities and professional results you can achieve. An experienced user spent 10-15 minutes creating each of these samples.
Use the powerful tools of the Medical Virology Solution for ConceptDraw DIAGRAM software to create your own infographics and diagrams of any complexity fast and easy, and then successfully use them in your work activity.
All source documents are vector graphic documents. They are available for reviewing, modifying, or converting to a variety of formats (PDF file, MS PowerPoint, MS Visio, and many more graphic formats) from the ConceptDraw STORE. The Medical Virology Solution is available for all ConceptDraw DIAGRAM users.