Vaccine Development and Immunology Success Stories

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Questions and Answers

What is a significant advantage of whole inactivated vaccines?

They do not require any booster doses.

They include multiple antigenic determinants. (correct)

They provide lymphatic tissue immunity.

They are always administered orally.

Which of the following is NOT a disadvantage of whole inactivated vaccines?

They completely eliminate the need for adjuvants. (correct)

Limited activation of mucosal immunity.

They require multiple immunizations.

Potential for adverse reactions from exotoxins or endotoxins.

What characterizes virus-like particles (VLPs) in comparison to traditional vaccines?

They create authentic antigenic structures without nucleic acids. (correct)

They contain viral nucleic acid for stronger immunity.

They are capable of causing infection.

They require a single dose for immunity.

What is a common characteristic of subunit vaccines?

They require adjuvants for effective immunogenicity. (A) Signup and view all the answers

What strategy is utilized in mRNA vaccines, such as those from Pfizer/BioNTech and Moderna?

Use of mRNA encapsulated in nanoparticles. (A) Signup and view all the answers

What is primarily focused on when developing vaccines to ensure long-term immunity?

Activation of immunity associated with pathogen protection (C) Signup and view all the answers

Which of the following represents a major advantage of vaccine-induced herd immunity?

Increases overall population immunity without further interventions (B) Signup and view all the answers

Which factor complicates the development of effective influenza vaccines?

Antigenic drift and shift (D) Signup and view all the answers

Which vaccine type is NOT included in the common categories listed?

Protein-based vaccines (B) Signup and view all the answers

What aspect of vaccine development is closely linked with the concept of passive immunization?

The direct administration of antibodies to individuals (B) Signup and view all the answers

Which of the following vaccines has shown significant impact in reducing cancer incidence?

Hepatitis B virus vaccine (D) Signup and view all the answers

Which type of antigenic variation is associated with significant pandemic potential in animal flu?

Gene reassortment (C) Signup and view all the answers

Which statement about live attenuated vaccines is accurate?

They can elicit a strong immune response mimicking natural infection. (C) Signup and view all the answers

What is a primary disadvantage of live attenuated vaccines?

They have the potential for genetic reversion to a wild type. (A) Signup and view all the answers

Which of the following statements is true regarding live recombinant vaccines?

They stimulate CD8+ killer T cells without the risk of reversion. (B) Signup and view all the answers

What is a major advantage of mRNA vaccines like those from Pfizer and Moderna?

They are not subject to concerns about genetic reversion. (D) Signup and view all the answers

How do killed virus vaccines primarily stimulate the immune system?

Through class II presentation of purified proteins. (B) Signup and view all the answers

What characteristic of live attenuated vaccines contributes to their effectiveness?

They can activate multiple arms of the immune system through replication. (D) Signup and view all the answers

What is a challenge associated with the use of live recombinant vaccines?

Ensuring the immunogenic parts are strong enough to prevent infections. (C) Signup and view all the answers

In the context of immune response, what is a key differentiator of live vaccines compared to killed virus vaccines?

Live vaccines stimulate class I antigen presentation. (A) Signup and view all the answers

What populations should avoid live attenuated vaccines?

Immunocompromised individuals, including those with acquired immunodeficiency. (A) Signup and view all the answers

What is the main reason why the elderly and frail are considered a vulnerable group regarding COVID-19?

Their immune systems are less robust and may not respond as effectively to vaccines or infection. (B) Signup and view all the answers

Based on the provided information, how long do antibodies generated by vaccination typically offer some protection against actual infection?

Several months. (A) Signup and view all the answers

According to the content, what is the primary function of memory B and T cells in the context of COVID-19 vaccination?

To quickly recognize and eliminate the virus upon re-exposure. (A) Signup and view all the answers

According to the content, what is the most likely reason for the relatively low vaccination rate among Canadians over 60?

There is a significant level of vaccine hesitancy among this age group. (C) Signup and view all the answers

Based on the provided information, which group of people may have a weaker immune response to a COVID-19 vaccine?

Individuals who have received a transplant or are on immunosuppressive medication. (D) Signup and view all the answers

The passage mentions that the COVID-19 vaccines are not great at preventing actual virus infection. How does this statement relate to the concept of herd immunity?

It highlights that achieving herd immunity will require a higher vaccination rate to compensate for the vaccine's limited efficacy in preventing infection. (A) Signup and view all the answers

Which of the following vaccines has demonstrated the greatest reduction in neutralizing antibody titers against the Beta variant?

Moderna (D) Signup and view all the answers

Based on the provided information, which of the following best describes the primary factor driving the need for updated COVID-19 vaccines?

The emergence of new variants that evade the immune system (D) Signup and view all the answers

The inclusion of both the original Wuhan sequence and the Omicron BA.1 sequence in the Moderna bivalent vaccine suggests a strategy to:

Boost immunity against the original strain while providing protection against Omicron (C) Signup and view all the answers

Which of the following nanoparticle-based therapies utilizes an albumin-bound formulation?

Abrazane (D) Signup and view all the answers

The information provided about COVID-19 vaccines suggests that the effectiveness of these vaccines is...

Dependent on the specific variant circulating in the population (B) Signup and view all the answers

Based on the provided information, which of these statements about Doxil is NOT true?

Doxil has been shown to be more effective than traditional chemotherapy (B) Signup and view all the answers

The information on COVID-19 vaccine efficacy against different variants suggests that...

The vaccine's effectiveness may vary depending on the specific variant and the type of vaccine (C) Signup and view all the answers

Which of the following statements best describes the current understanding of the immune response after double (or triple/boosted) vaccination with COVID-19 vaccines?

Waning of immunity is a natural process, but booster doses can effectively restore protection. (A) Signup and view all the answers

Study Notes

Vaccine Development (Lecture + SGS)

Rod Russell - Phase 2
Objectives include describing how vaccination induces long-term immunity, the advantages and disadvantages of different vaccine types, and comparing/contrasting active, passive, therapeutic, and prophylactic vaccines.
The plan involves a 30-minute lecture, a 20-minute exercise, and a 30-60-minute discussion.
The promise of vaccines lies in specifically activating immunity for protection from infection or disease, achieving immunity without infection or sickness, and increasing safety through herd immunity.

Success Stories of Immunology

Smallpox was globally eradicated in 1980, marking a major triumph.
Polio eradication may be the next goal.
The hepatitis B vaccine significantly decreased cancer incidence.
COVID-19 vaccines are a recent success.

Why It's Difficult to Develop Useful Vaccines

Influenza is an example, as a single virus type is responsible for most cases each year.
Immunity develops mainly through antibody responses against viral proteins (HA), and also others (NA).
Influenza virus exhibits antigenic variation through antigenic drift and antigenic shift.

Antigenic Variation

Antigenic drift: Changes in epitopes of hemagglutinin in the influenza virus occur every 2-3 years, preventing existing antibodies from binding effectively. Ab and T-cell epitopes are affected.
Antigenic shift: An infrequent but potentially pandemic event where RNA segments are exchanged between viral strains in different hosts. This leads to novel hemagglutinins, and no cross-protective immunity.

SARS-CoV-2 Antigenic Variation

SARS-CoV-2 uses antigenic drift.

Types of Vaccines Used

Live attenuated
Whole inactivated
Virus-like particles
Subunit vaccines
Live recombinant
Conjugated
DNA
mRNA (with a question mark).

Remember Your Immunology

Killed virus, recombinant, or purified protein vaccines stimulate antibody production through class II presentation.
Live attenuated and live recombinant vaccines lead to intracellular infection, promoting class I and class II antigen presentation, and triggering antibody and cytotoxic T cell responses.

What is an RNA Vaccine?

Pfizer and Moderna use mRNA in a nanoparticle delivery system.

Nanoparticle Delivery

Nanoparticles are used as drug carriers in various therapies, including cancer treatments.
They encapsulate drugs to reduce side effects with a variety of materials used (Carbon nanotubes, metal oxides, gold nanoparticle, etc).

Nanoparticles as Therapies

Doxil: An anti-cancer drug (doxorubicin) encapsulated in a liposome that reduces side effects.
Abraxane: A nanoparticle formulation of paclitaxel used to treat several cancers.

COVID-19 Vaccine Pipeline

Data on vaccine types (mRNA LNP, mRNA LNP, Chimp Adeno 5, Human Adeno26, Protein SU), doses, cold storage requirements, efficacy, and specific variant impacts are provided.

Bivalent Vaccines

Moderna and Pfizer are using bivalent formulations.
These include original Wuhan and Omicron (BA.1, BA.4/BA.5) sequences.
Data is in progress to determine long-term efficacy.

The Immune Response

A primary immune response followed by a secondary response is described.
Antibody levels wane over time, which is normal.

The Two Phases of the Immune Response

Antibodies in the blood can prevent infection for 2-3 months.
Memory B and T cells eliminate the virus long-term.

The "Vaccinated Vulnerable" Group

Elderly and frail individuals, people with immunocompromised systems (genetic or acquired), and those battling or recovering from cancer can have dampened immune responses to vaccines and viruses.
Recent data from Canada indicates a significant portion of the population over 60, did not experience COVID.

Are Vaccines Failing?

Vaccines are not failing for preventing severe disease, but may not be completely effective at preventing actual infections.
Graph data on Canadian COVID cases and deaths from 2020 to 2022 provide context.

Can we talk about Herd Immunity Yet?

The criteria for herd immunity depend on specific end goals.
Herd immunity can be achieved through vaccination and natural infections.

Burning Questions About COVID-19 Vaccines

Key questions regarding COVID-19 vaccine effectiveness, mixing/matching, delayed dosing, effectiveness against variants, immune escape, and annual vaccine evolution are outlined.

Exercise: Design a COVID-19 Vaccine

A COVID-19 vaccine design exercise is discussed.
Different vaccine types (Live Attenuated, Live Recombinant, Whole Inactivated, Virus-Like Particles, Subunit Vaccines, mRNA Vaccine) are assigned to groups.
The exercise demands answering vaccine design and production, testing, expected immune response, and safety concerns related questions.

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Description

This quiz covers important aspects of vaccine development, including how vaccination induces long-term immunity and the effectiveness of various vaccine types. It highlights significant achievements in immunology, such as the eradication of smallpox and advancements in COVID-19 vaccines. Explore the challenges faced in developing useful vaccines and the implications for public health.