The current Influenza vaccine includes

Correct Answer: B

Rationale: Step 1: The current Influenza vaccine is designed to provide protection against multiple strains to increase effectiveness. Step 2: Option B includes a combination of different strains (H1N1, H5N1, and B), covering a broader spectrum of the virus. Step 3: Including different strains helps to address potential mutations and variations in circulating viruses. Step 4: Option B is the most comprehensive choice compared to others, offering a more robust protection against various strains. Summary: Option A is too limited with only 3 type A strains, while option C focuses only on 2009 H1N1 strain. Option D is also limited to only the most common seasonal H1N1 strain. Option B stands out as the correct choice for its broad coverage of different strains.

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.

Correct Answer: C

Rationale: Paul Ehrlich introduced the concept of discrimination between self and non-self through his "horror autotoxicus" theory. He proposed that the immune system can differentiate between harmful non-self antigens and self-antigens. Ehrlich's theory laid the foundation for understanding immune responses and the development of immunology. Metchnikoff focused on phagocytosis, Pasteur on microbiology, and Janeway on innate immunity, not specifically on self vs. non-self discrimination.

Correct Answer: B

Rationale: Neutrophils play a crucial role in the immune response by engulfing and destroying pathogens through a process called phagocytosis. This is essential for eliminating harmful invaders from the body. Neutrophils do not produce antibodies (choice A), activate lymphocytes (choice C), or synthesize cytokines (choice D), which are functions typically carried out by other immune cells like B cells and macrophages. Therefore, the correct answer is B as it directly aligns with the primary function of neutrophils in the immune response, which is to combat infections by destroying pathogens.

Correct Answer: C

Rationale: Pattern recognition in innate immunity, as proposed by Janeway, involves identifying common pathogen-associated molecular patterns (PAMPs). This is crucial for initiating the immune response against pathogens. PAMPs are specific molecular patterns found on pathogens but not on host cells. By recognizing these patterns, the innate immune system can quickly and effectively identify potential threats and trigger the appropriate immune response. Explanation of why other choices are incorrect: A: Specific recognition of antigens is a function of adaptive immunity, not innate immunity. B: Binding toxins to create immunity is not the primary role of pattern recognition in innate immunity. D: Suppressing lymphocyte activation is not the role of pattern recognition in innate immunity; rather, it is involved in activating immune responses against pathogens.