Explain why the concentration of antibody molecules shown in the graph decreased to zero in person R by day .
Important Questions on Pathogens and Immunity
Explain why the concentration of antibody molecules shown in the graph for person S did not start to increase until days after the injection.
Describe the incidence of measles cases in the USA between and .
Describe the effect of the introduction of vaccination on the number of measles cases.
Copy and complete the table to indicate the type of immunity- active or passive, that is obtained by each method.
| Method | Type of immunity |
| Having a disease and recovering from it | |
| Feeding a baby on breast milk | |
| Being injected with antibodies | |
| Receiving a measle's vaccination as a child |
An aid worker is asked to travel immediately to a region where a disaster has taken place. There is a high risk of her being exposed to pathogens that could cause serious diseases. Her doctor recommends that before travelling she should have an injection of antibodies rather than a vaccination of weakened pathogens. Explain the reasons for this.
