Herd Immunity and Vaccination Strategies

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Questions and Answers

What is the total amount of formaldehyde received from three doses of the vaccine?

0.2 mg

0.4 mg

0.1 mg

0.3 mg (correct)

Which type of mercury is NOT present in any vaccine?

Elemental mercury

Organic mercury

Metil mercury (correct)

Etil mercury

What is the maximum allowable amount of aluminum in a liter of water according to established rules?

0.5 mg

0.1 mg

0.2 mg (correct)

1.0 mg

What was the cost of drugs in 2015 as reported in the content?

28.9 billion euros Signup and view all the answers

What is the approximate annual cost for follow-up after organ transplantation due to chronic hepatitis?

17,000 euros Signup and view all the answers

In terms of vaccine response, how do females typically respond compared to males?

Females respond greater than males Signup and view all the answers

How much aluminum do we ingest in total throughout a year from drinking water?

700 mg Signup and view all the answers

What was the cost of antiacids in comparison to vaccines?

923.3 million euros Signup and view all the answers

What effect does low doses of beta-estradiol have on inflammatory cytokines?

It increases their release. Signup and view all the answers

How does progesterone affect macrophages?

It induces the differentiation into M2 macrophages. Signup and view all the answers

Which statement correctly describes the effect of testosterone on immune cells?

It promotes an anti-inflammatory profile. Signup and view all the answers

In which scenario is there typically a greater response to vaccines in males?

In aged adults receiving the tetanus vaccine. Signup and view all the answers

Which immune cells have receptors for sexual hormones?

Both innate and adaptive immune cells. Signup and view all the answers

What is the impact of high doses of beta-estradiol on cytokines?

Decrease the production of cytokines. Signup and view all the answers

Which type of T cells does progesterone upregulate?

Th2 cells and regulatory T cells. Signup and view all the answers

What distinguishes the immune response in females compared to males generally?

Females usually have a greater response to vaccines. Signup and view all the answers

What happens to receptors in anergic B cells?

They express less receptors and cannot change the receptor. Signup and view all the answers

What is the consequence of anergic B cells not having adequate BCR?

They remain non-responsive in exiting the bone marrow. Signup and view all the answers

What mechanism leads to the degradation of BCR and TCR in anergic B cells?

Ubiquitination followed by proteasomal degradation. Signup and view all the answers

In anergic B cells, what is recruited instead of the kinase SYK?

Phosphatase. Signup and view all the answers

Which transcription factor is NOT involved in the activation pathways of anergic B cells?

CREB. Signup and view all the answers

How does anergy affect the immune response of B cells?

It prevents triggering by peripheral antigens. Signup and view all the answers

Which of the following activates downstream signaling pathways in B cells?

Activation of specific kinases. Signup and view all the answers

What is the primary effect of ubiquitination on BCR and TCR in anergic B cells?

It targets them for degradation. Signup and view all the answers

What is the primary cause of B cell anergy in the experiment with the transgenic mice?

Continuous presence of a specific antigen Signup and view all the answers

How was it determined that the anergy in B cells was independent of T cells?

By irradiating a mouse to eliminate original T cells Signup and view all the answers

What happens to B cells' IgM levels during anergy?

IgM levels decrease significantly Signup and view all the answers

What type of dendritic cell is described as having a reduced ability to activate T cells?

Tolerogenic dendritic cell Signup and view all the answers

Which of the following receptors is implicated in inhibiting B cell responses?

CD22 Signup and view all the answers

What is the main characteristic of long-lasting T cell anergy compared to B cell anergy?

T cell anergy is generally more enduring over time Signup and view all the answers

What occurs if the antigen is not presented for an extended period to B cells experiencing anergy?

B cells will regain expression of their BCR Signup and view all the answers

Which process leads to the downregulation of effector functions in B cells?

Binding of inhibitory immunoglobulins Signup and view all the answers

Which therapy primarily uses antihistamines to manage early phase allergic reactions?

Conventional therapies Signup and view all the answers

What is the main aim of hypo-sensitization therapy?

To induce tolerance against allergens Signup and view all the answers

Which cytokine is NOT typically targeted by monoclonal antibody therapies in immunotherapy?

IL6 Signup and view all the answers

What is a consequence of the presence of excess levels of IgG in the bloodstream?

Type II hypersensitivity reactions Signup and view all the answers

In type II hypersensitivity, what triggers phagocytosis by macrophages?

Binding of IgG to surface proteins Signup and view all the answers

Which of the following statements is true regarding corticosteroids as a therapy?

They are primarily used to manage inflammation. Signup and view all the answers

What is a key safety concern associated with hypo-sensitization therapy?

It can cause anaphylaxis if not monitored. Signup and view all the answers

Which type of hypersensitivity is characterized by the involvement of IgG antibodies?

Type II hypersensitivity Signup and view all the answers

What is the effect of transforming an antigen into a tolerogenic form on the immune response?

It completely impairs both primary and secondary immune responses. Signup and view all the answers

Which factor does NOT contribute to the immunogenicity of a protein?

The number of peptide bond formations in proteins. Signup and view all the answers

Why are dendritic cells critical in the immune response to antigens?

They efficiently trigger T cell activation through antigen presentation. Signup and view all the answers

How does the use of D amino acids in a protein synthesis affect its immunogenicity?

It transforms the protein into a tolerogenic one. Signup and view all the answers

What happens to the immune response when an antigen is presented in a soluble form compared to a complex form?

The complex form is generally more immunogenic. Signup and view all the answers

What is the significance of dose in the context of immune tolerance?

Both low-zone and high-zone tolerances exist for each antigen. Signup and view all the answers

Which characteristic of an antigen is most likely to lead to its recognition by FCγ receptors?

Formation of an immune complex. Signup and view all the answers

What would be the consequence of a very small antigen injected into a mouse?

It might fail to trigger an immune response. Signup and view all the answers

Study Notes

Herd Immunity

Herd immunity occurs when a large proportion of a population is vaccinated, blocking virus spread and protecting vulnerable individuals.
Vaccinated individuals prevent virus transmission, safeguarding those unable to be vaccinated.

Triumphs and Defeats of Vaccines

Many vaccines effectively combat infections, even leading to eradication (e.g., smallpox) or reduced incidence (e.g., polio).
Some vaccines are less effective due to microbial evasion of immunity (e.g., Schistosoma and Leishmania) or antigen mutation (e.g., influenza virus).
Continued development of vaccines for challenging diseases (e.g., HIV, Ebola) is ongoing.
Vaccine resistance often stems from religious beliefs, emotional reactions, misleading news, and a lack of knowledge about vaccine efficacy and risks.

Vaccine Calendar

Specific vaccinations are commonly administered during childhood.
Different vaccines may require multiple doses administered over time.
Vaccination schedules often vary by country (e.g., Italy).

Vaccination Concerns

Early concerns about vaccinations stemmed from a now-discredited study linking a vaccine to autism.
Vaccination is generally a safe and effective preventive measure.

Vaccine Safety

Current vaccines do not contain toxic substances such as mercury or formaldehyde.
Aluminum is a naturally occurring metal in water and food and is present in vaccines in very low levels compared to natural intake levels.

Vaccine Efficacy and Herd Immunity

Herd immunity is achieved when a significant proportion of a population is vaccinated, reducing virus spread and protecting those who cannot be vaccinated.
Vaccinations are most impactful when a large proportion of a population is immune to a disease.

Gender Differences in Vaccine Responses

Women generally exhibit stronger immune responses to various vaccines than men, with enhanced antibody and proliferation levels.
Progesterone may decrease cytokine production, reducing inflammation, while estrogen appears to heighten certain immune responses.

Immune Tolerance

Tolerance is the adaptive immune system's ability to distinguish and disregard "self" antigens.
Central tolerance occurs during lymphocyte development in the bone marrow (B cells) and thymus (T cells), eliminating cells that recognize "self".
Peripheral tolerance involves mechanisms to inactivate self-reacting lymphocytes outside the primary lymphoid organs.

Negative Selection of Self-Reactive T and B Cells

Negative selection in the thymus removes T cells that react too strongly with self-antigens.
Similar selection processes occur in the bone marrow to eliminate self-reactive B cells.

Peripheral Tolerance

Peripheral tolerance prevents mature self-reactive lymphocytes from attacking self-tissues.
This tolerance may occur in the absence of a full response to the antigen or through the activation of an anergic state.

B and T Cell Anergy

Anergy is a state of unresponsiveness to an antigen due to antigen presentation without appropriate co-stimulation.
This prevents lymphocytes from initiating an exaggerated response to "self".

Inhibitory Receptors

Inhibitory receptors regulate immune responses and prevent excessive or destructive immune reactions.
These receptors modulate immune cell activity to maintain homeostasis.

Immune-Privileged Sites

These tissues limit immune responses to protect function.
Examples include eyes, brain and testes.

Hypersensitivity Reactions

Hypersensitivity responses occur when the immune system overreacts to harmless substances.
These responses involve a sensitization phase and an effector phase.
Types of hypersensitivity responses (e.g., Type I, II, III, IV) differ in their mechanisms and clinical presentations.

Type I Hypersensitivity

This response is mediated by IgE, causing mast cell degranulation and the release of inflammatory mediators.
Symptoms include itching, swelling, and difficulty breathing.
Allergic responses are a common example of Type I.

Type IV Hypersensitivity

This delayed-type hypersensitivity is mediated by T cells.
This response is associated with chronic inflammation and tissue damage; examples include contact dermatitis, granuloma formation, and transplant rejection.

Experimental Tolerance

Tolerance can be facilitated by manipulating antigen form or dose.
This allows for antigen-specific regulation of immune responses.

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Description

Explore the concepts of herd immunity and the effectiveness of vaccines in combating infectious diseases. This quiz covers vaccination schedules, triumphs in vaccine history, and challenges faced by modern vaccines. Test your knowledge on how vaccines protect not only individuals but communities as a whole.