Nokea
Adding adjuvants in Flu vaccines, such as AS03 used in Canada in the 2009 H1N1 vaccine is thought to
- A. Induce danger signals
- B. Generally boost the innate immune response
- C. Create a slower release of antigen (antigen depot)
- D. All of the above is correct
Correct Answer: D
Rationale: Step 1: Adjuvants like AS03 induce danger signals by activating innate immunity, enhancing the response to the vaccine.
Step 2: Adjuvants generally boost the innate immune response by increasing antigen presentation and cytokine production.
Step 3: Adjuvants create a slower release of antigen, forming an antigen depot which prolongs immune stimulation.
Summary: Choice D is correct because adjuvants like AS03 do induce danger signals, boost the innate immune response, and create a slower release of antigen, leading to enhanced vaccine efficacy. Choices A, B, and C are incorrect as they do not encompass all the effects of adjuvants in flu vaccines.
You may also like to solve these questions
Which part of the antibody determines its physiological effects?
- A. Fab fragment
- B. Fc fragment
- C. Variable region
- D. Antigen-binding site
Correct Answer: B
Rationale: The correct answer is B: Fc fragment. The Fc fragment of an antibody determines its physiological effects by interacting with immune cells and other effector molecules. It mediates processes like opsonization, complement activation, and antibody-dependent cell-mediated cytotoxicity. The Fab fragment (A) contains the antigen-binding site but does not directly influence physiological effects. The variable region (C) is part of both the Fab and Fc portions and contributes to antigen specificity but does not solely determine physiological effects. The antigen-binding site (D) is located within the Fab portion and is responsible for binding to specific antigens, not for exerting physiological effects.
The C3 convertase is
- A. An opsonin facilitating the phagocytic process
- B. Part of the Membrane Attack Complex (MAC) that leads to lysis of targets
- C. An enzyme able to cleave C3
- D. An inhibitor of C3b
Correct Answer: C
Rationale: The correct answer is C because the C3 convertase is an enzyme that cleaves C3 into C3a and C3b, an essential step in the complement cascade. This enzyme is crucial for the initiation of both the classical and alternative pathways. Choice A is incorrect as opsonins enhance phagocytosis but are not directly related to C3 convertase. Choice B is incorrect as the MAC is formed by the terminal complement components, not the C3 convertase. Choice D is incorrect as C3b is not an inhibitor but a product of C3 cleavage by the C3 convertase.
What is Louis Pasteur's main contribution to immunology?
- A. Development of the smallpox vaccine
- B. Discovery of phagocytosis
- C. Germ theory of disease and vaccine development
- D. Theory of innate immunity
Correct Answer: C
Rationale: Louis Pasteur's main contribution to immunology is the germ theory of disease and vaccine development. Firstly, Pasteur's germ theory revolutionized our understanding of infectious diseases by demonstrating that microorganisms are the cause. Secondly, he developed the concept of vaccination by creating vaccines for diseases such as rabies and anthrax, laying the foundation for modern immunology. The other choices are incorrect because:
A: Pasteur worked on the rabies vaccine, not the smallpox vaccine.
B: Phagocytosis was discovered by Metchnikoff, not Pasteur.
D: Pasteur did not propose the theory of innate immunity.
In a client with AIDS,a CD4 cell count above ______ mm³ would indicate that antiretroviral therapy is being effective.
- A. 250
- B. 1000
- C. 500
- D. 275
Correct Answer: C
Rationale: A CD4 count above 500 mm³ indicates a strong immune response and effective antiretroviral therapy.
Which of the following restriction endonucleases produce fragments with blunt ends?
- A. Sacl
- B. EcoRI
- C. Smal
- D. HindIII
Correct Answer: C
Rationale: The correct answer is C: Smal. Smal is a restriction endonuclease that cuts DNA at specific sequences, producing fragments with blunt ends. Smal recognizes the sequence CCCGGG and cuts between the two C's on both strands, resulting in blunt-ended fragments.
Explanation for incorrect choices:
A: Sacl - Sacl produces sticky ends, not blunt ends.
B: EcoRI - EcoRI produces sticky ends with overhangs.
D: HindIII - HindIII also produces sticky ends with overhangs.
In summary, Smal is the only enzyme among the choices that generates DNA fragments with blunt ends.