IB Biology Topic C3.2.17 Herd Immunity and the Prevention of Epidemics Revision Notes (SL/HL)

IB Biology Topic C3.2.17 Herd Immunity and the Prevention of Epidemics Revision Notes (SL/HL) | RevisionDojo

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Herd Immunity Protects the Vulnerable When Enough of a Population Is Immune

Herd immunity happens when a high proportion of a population is immune to a disease.
With so few people left to infect, chains of transmission break down.
This gives indirect protection to people who are not immune, such as newborns, the elderly, and the immunocompromised.

Note

See C3.2.16 for how vaccines create the immunity that builds herd immunity.

How Herd Immunity Breaks the Chain of Transmission

Immune people do not catch or pass on the disease, so it has nowhere to go.
Non-immune people are shielded because the disease rarely reaches them.

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Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

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Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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Herd Immunity Protects the Vulnerable When Enough of a Population Is Immune

Herd immunity happens when a high proportion of a population is immune to a disease.
With so few people left to infect, chains of transmission break down.
This gives indirect protection to people who are not immune, such as newborns, the elderly, and the immunocompromised.

Note

See C3.2.16 for how vaccines create the immunity that builds herd immunity.

How Herd Immunity Breaks the Chain of Transmission

Immune people do not catch or pass on the disease, so it has nowhere to go.
Non-immune people are shielded because the disease rarely reaches them.

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic C3.2.17: Herd Immunity and the Prevention of Epidemics Notes

Herd Immunity Protects the Vulnerable When Enough of a Population Is Immune

How Herd Immunity Breaks the Chain of Transmission

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Herd Immunity Protects the Vulnerable When Enough of a Population Is Immune

How Herd Immunity Breaks the Chain of Transmission

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics