What defines an outbreak of an infectious disease?

• When a disease infects a small, isolated group of people.

• When an infectious disease infects many more people than would be expected in a certain group.

• When a disease spreads globally, affecting multiple continents.

• When a disease has been completely eliminated from a population.

What are the two main ways an outbreak of an infectious disease typically ends?

• Through global eradication or by becoming a pandemic.

• By the pathogen mutating into a harmless form or by widespread use of antibiotics.

• By eliminating the environmental reservoir or by limiting person-to-person transmission.

• When all infected individuals recover or when a new vaccine is developed.

What is herd immunity?

• When a pathogen becomes so weak it can no longer infect anyone.

• When a large number of people in a community are immune to a disease, protecting those who are not immune.

• When animals develop immunity to a disease, preventing its spread to humans.

• When individuals isolate themselves to prevent the spread of a disease.

How do vaccines help the adaptive immune system fight off pathogens?

• They directly kill all pathogens in the body.

• They introduce a weakened or dead version of a pathogen, allowing the immune system to learn to recognize and fight it.

• They boost the body's natural ability to self-isolate from infected individuals.

• They provide immediate, lifelong immunity without any prior exposure.

Which type of vaccine uses only bits of a whole pathogen, such as proteins on its surface or harmless versions of its toxins, to stimulate an immune response?

• Whole pathogen vaccines

• Nucleic acid vaccines

• Subunit vaccines

• Live-attenuated vaccines

How do nucleic acid vaccines work to prepare the body for a pathogen?

• They introduce a weakened form of the entire pathogen.

• They use genetic sequences to instruct the body's cells to create harmless antigens.

• They inject pre-made antibodies directly into the bloodstream.

• They expose the body to inactivated toxins produced by the pathogen.

Why might new vaccines need to be developed each year for the same disease?

• The human immune system forgets how to fight the disease after a year.

• Vaccine ingredients expire and become ineffective over time.

• Pathogens evolve and change their genetic material and antigens.

• It is a marketing strategy by pharmaceutical companies.

Besides the immediate illness, what long-term effects can serious infections have on the body?

• Increased resistance to future infections.

• Improved organ function and overall health.

• Persistent coughs, trouble breathing, or lung and kidney disease.

• Enhanced mental clarity and cognitive abilities.