Population Immunity
Population Immunity - Related Videos
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Visualization, Quantification, and Mapping of Immune Cell Populations in the Tumor Microenvironment
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Cited by 14 •
2020
Here, we describe a simple and accessible strategy for visualizing, quantifying, and mapping immune cells in formalin-fixed paraffin-embedded tumor tissue sections. This methodology combines existing imaging and digital analysis techniques with the purpose of expanding the multiplexing capability and multiparameter analysis of imaging assays.
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Population Growth - Student Protocol
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2019
Exponential Population Growth Model ExpandNOTE: In these experiments you will use computer software to simulate different types of growth models. HYPOTHESES: The experimental hypothesis might be that if we increase either R, the reproductive rate or the initial population size, NT, that this will increase the population size after 10 generations in an exponential growth model compared to unmanipulated control populations. The null hypothesis may be that populations of different R and initial...
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Population Growth - Concepts
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2019
Population Models An ecological population is a group of individuals of a single species living in an area at the same time. To persist, a population must either grow or maintain its size. Population ecology is the study of how population size and age distribution change over time through interactions with other species and the environment as well as with individuals of their own species. A particularly important feature that is studied by ecologists is the rate at which a population grows or...
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Conservation of Small Populations
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2019
Small population sizes put a species at extreme risk of extinction due to a lack of variation, and a consequent decrease in adaptability. This weakens the chances of survival under pressures such as climate change, competition from other species, or new diseases. Large populations are more likely to survive pressures such as these, as such populations are more likely to harbor individuals that have genetic variants that are adaptive under new stresses. Small populations are much less likely to...
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What is the Immune System?
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2019
Overview The immune system comprises diverse biological structures and processes that protect the body from disease. These processes can be classified into innate and adaptive immunity. To work effectively, the immune system needs to detect pathogens by distinguishing the body’s own structures from foreign elements. If this determination fails, autoimmune diseases occur in which the immune system reacts against the body’s own tissue. The Innate Immune System Acts Fast and Non-specifically
FAQs
Population immunity reduces transmission by making infectious chains less likely to continue. When an infectious person encounters more immune individuals, fewer contacts are susceptible to infection, so opportunities for onward spread decline. This indirect protection can extend to susceptible community members who are not immune, making the distribution of immunity across a community relevant to biological transmission and public-health protection.
The required proportion is not fixed because it depends on how readily the pathogen spreads and how effectively immunity blocks infection or transmission. A more transmissible pathogen generally requires a larger immune proportion to interrupt spread, while weaker protection may reduce the effectiveness of the same coverage level. These factors help explain why population immunity targets differ among diseases.
Vaccination and prior infection can both contribute to population immunity, but their combined contribution must be interpreted through the effectiveness of the protection they produce. The relevant biological outcome is not simply the number of immune people, but whether immunity sufficiently reduces transmission. This distinction supports evaluating vaccine impact alongside existing immunity when planning disease-control programs.
If the immune proportion is insufficient, susceptible individuals remain available to sustain transmission, increasing the risk that infections will spread through a community. Monitoring this vulnerability is especially important for resurgent infections and emerging pathogens, because existing immunity may not provide adequate protection. Population immunity therefore changes the expected conditions for spread rather than guaranteeing that transmission cannot occur.
Monitoring immunity levels helps identify communities at risk by showing where protection is insufficient. It also allows programs to evaluate vaccine impact and compare changing levels of protection over time. Those observations can guide vaccination strategies, outbreak responses, and disease-control planning, linking measurements of community immunity with decisions about where protection needs to be strengthened.
A vaccination strategy can use population immunity estimates to determine whether community protection is likely to interrupt transmission. Planning considers the proportion that needs protection, the pathogen’s transmissibility, and how effectively immunity limits spread. Monitoring then helps identify communities at risk and evaluate vaccine impact, allowing disease-control programs to direct attention where protection is insufficient.
For outbreak prediction, population immunity provides context for judging how many susceptible people remain available for transmission. Lower protection can signal greater vulnerability, whereas stronger protection may reduce opportunities for spread. During an outbreak or disease resurgence, these assessments support disease-control responses; they also help interpret whether observed changes reflect vaccination impact or continuing gaps in community protection.