3.2.4 Vaccines and Immunity

What is the primary purpose of vaccines?

• To cure diseases

• To provide protection against diseases

• To diagnose diseases

• To enhance physical strength

Answer explanation

The primary purpose of vaccines is to provide protection against diseases by stimulating the immune system to recognize and fight pathogens, rather than curing diseases or diagnosing them.

What is herd immunity?

• Immunity achieved by a single individual

• Immunity that occurs when a large portion of a population becomes immune to a disease

• Immunity that is passed from mother to child

• Immunity that is acquired through natural infection only

Answer explanation

Herd immunity occurs when a significant portion of a population becomes immune to a disease, either through vaccination or previous infections, reducing the spread and protecting those who are not immune.

Which of the following best describes active immunity?

• Immunity acquired through the transfer of antibodies

• Immunity developed after exposure to a disease or through vaccination

• Immunity that is present at birth

• Immunity that is temporary and short-lived

Answer explanation

Active immunity is best described as immunity developed after exposure to a disease or through vaccination, as it involves the body's own immune response to pathogens or vaccines.

Which of the following is an example of passive immunity?

• Vaccination against measles

• Antibodies received from mother's milk

• Recovery from chickenpox

• Immunity developed after a flu infection

Answer explanation

Passive immunity occurs when antibodies are transferred from one individual to another. Antibodies received from mother's milk provide immediate protection to the infant, making it an example of passive immunity.

What is one ethical issue associated with the use of vaccines?

• Vaccines are always 100% effective

• Vaccines can cause diseases they are meant to prevent

• Mandatory vaccination policies may infringe on personal freedoms

• Vaccines are too expensive for any government to afford

Answer explanation

Mandatory vaccination policies can raise ethical concerns as they may limit individual autonomy and personal freedoms, leading to debates about the balance between public health and individual rights.

Which of the following is NOT a benefit of herd immunity?

• Protects those who cannot be vaccinated

• Reduces the spread of contagious diseases

• Guarantees individual immunity for everyone

• Helps prevent outbreaks

Answer explanation

Herd immunity protects the community but does not guarantee individual immunity for everyone. Some individuals may still be susceptible to diseases despite high vaccination rates.

How does active immunity differ from passive immunity?

• Active immunity is temporary, while passive immunity is long-lasting

• Active immunity involves the production of antibodies by the immune system, while passive immunity involves receiving antibodies from another source

• Active immunity is only acquired through vaccination, while passive immunity is only acquired through natural infection

• Active immunity is inherited, while passive immunity is acquired

Answer explanation

Active immunity is generated by the immune system producing its own antibodies, often through infection or vaccination. In contrast, passive immunity involves receiving antibodies from another source, providing immediate but temporary protection.

Which of the following is a common misconception about vaccines?

• Vaccines can prevent certain diseases

• Vaccines are thoroughly tested for safety

• Vaccines can cause autism

• Vaccines help achieve herd immunity

Answer explanation

The belief that vaccines can cause autism is a common misconception. Extensive research has shown no link between vaccines and autism, while vaccines are proven to be safe and effective in preventing diseases and achieving herd immunity.

What is the role of the immune system in active immunity?

• To passively receive antibodies from another source

• To produce its own antibodies in response to an antigen

• To remain inactive until a disease is contracted

• To reject all foreign substances

Answer explanation

The immune system's role in active immunity is to produce its own antibodies in response to an antigen, allowing for a targeted defense against pathogens, unlike passive immunity which involves receiving antibodies from another source.

Why might some individuals be unable to receive vaccines?

• They are too expensive

• They have a compromised immune system

• They are allergic to all medications

• They do not believe in science

Answer explanation

Individuals with a compromised immune system may be unable to receive vaccines due to the risk of adverse reactions or insufficient immune response. This makes them a vulnerable group in vaccination scenarios.