COVID-19 Vaccines Overview (L10)

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Questions and Answers

What type of vaccine is the Astra Zeneca/Oxford Adenoviral Vector Vaccine based on?

Protein subunit

mRNA technology

Adenovirus vector (correct)

Inactivated virus

What was a significant error observed in the Astra Zeneca vaccine trials?

Lack of asymptomatic testing

Delay between doses

Math error leading to half doses (correct)

Higher doses given to participants

What is one of the main recommendations made by the CDC regarding the Johnson and Johnson vaccine?

No additional doses are needed

Receive a booster of an mRNA vaccine (correct)

Switch to a different vaccine for better efficacy

Only one dose is sufficient

As of May 2023, what is the status of the Johnson and Johnson vaccine in the US?

It is no longer available Signup and view all the answers

Before testing the SARS-CoV-2 vaccine, what had the Astra Zeneca team already been working on?

Coronaviruses Signup and view all the answers

What unique feature was included in the clinical trial for the Astra Zeneca vaccine?

Testing for asymptomatic infections post-immunization Signup and view all the answers

What type of immunity may the Astra Zeneca vaccine potentially provide according to assumptions?

Longer-lasting T cell immunity Signup and view all the answers

How many clinical trials were conducted for vaccines prior to the discussed vaccines?

109 in human trials Signup and view all the answers

What is the effectiveness of the newer herpes zoster vaccine compared to the first generation?

Over 90% Signup and view all the answers

Why is the safety profile of the Astra Zeneca vaccine considered established?

Previous work on the Ebola virus vaccine Signup and view all the answers

What does the term 'second generation' vaccines refer to?

Vaccines that improve upon first-generation designs Signup and view all the answers

What component of the Novavax protein subunit vaccine allows the SPIKE protein to enter the cell?

Lipids Signup and view all the answers

Which of the following is NOT a component of the Novavax vaccine?

Preservatives Signup and view all the answers

By the end of 2022, how many COVID-19 hospitalizations were prevented in the United States?

18.5 million Signup and view all the answers

What has caused the waning Vaccine Effectiveness (VE) of COVID-19 vaccines over time?

Accumulation of point mutations at the Receptor Binding Domain Signup and view all the answers

What sublineage of SARS-CoV-2 accounted for more than 99% of sequenced specimens by September 2023?

XBB-sublineage Signup and view all the answers

What year did Novavax receive Emergency Use Authorization (EUA)?

2022 Signup and view all the answers

Which part of the Novavax vaccine components acts to activate the innate immune system?

Adjuvant: Fraction A and C Signup and view all the answers

What was the estimated number of COVID-19 deaths prevented in the United States by the end of 2022?

3.2 million Signup and view all the answers

Which characteristic of the newer COVID-19 vaccines necessitates annual updates?

Rapid mutation of SARS-CoV-2 Signup and view all the answers

What is a key challenge in demonstrating the efficacy of a vaccine?

Measuring the length of time antibody levels stay high Signup and view all the answers

What factor contributes to the occurrence of vaccine breakthrough cases in COVID-19?

Mutations in the virus that allow it to evade immunity Signup and view all the answers

Which of the following is not typically a component measured in evaluating vaccine effectiveness?

Market acceptance of the vaccine Signup and view all the answers

What is an anticipated challenge regarding immunity after vaccination?

How long immunity lasts and the need for boosters Signup and view all the answers

What is a significant barrier to achieving herd immunity for viral infections such as COVID-19?

The existence of multiple coronaviruses in animal reservoirs Signup and view all the answers

What type of peptides do individuals with natural SARS-CoV-2 infection release interferon gamma in response to?

Both spike and non-spike peptides Signup and view all the answers

In vaccinated individuals, what type of peptides elicits a high interferon gamma release?

Spike peptides Signup and view all the answers

What is the expected interferon gamma release from naïve individuals without vaccine or natural infection?

No release of interferon gamma Signup and view all the answers

How can the effectiveness of a vaccine be assessed according to the information provided?

By analyzing the ability of serum antibody to neutralize pseudotyped virus or live virus Signup and view all the answers

What cells are stimulated to release interferon gamma in the described assays?

PBMC (Peripheral Blood Mononuclear Cells) Signup and view all the answers

Which group would likely show the highest interferon gamma production when tested?

Individuals with natural infection Signup and view all the answers

What does a low interferon gamma release in response to peptides suggest about an individual's immune status?

They are naïve to the virus Signup and view all the answers

Which characteristic is associated with vaccinated individuals regarding interferon gamma production?

High response specifically to spike peptides Signup and view all the answers

Which measurement is NOT indicative of vaccination effectiveness based on the provided content?

Side effects occurrences post-vaccination Signup and view all the answers

What role do non-spike peptides play in the immune response of individuals with natural SARS-CoV-2 infection?

They elicit a strong interferon gamma response Signup and view all the answers

What significant element does the mRNA vaccine construct for COVID-19 contain to enhance stability?

Conserved region of Spike Signup and view all the answers

What is the primary endpoint for the clinical trials of both Moderna and Pfizer vaccines?

Symptomatic infection rates Signup and view all the answers

What factor contributed to the different storage requirements for the Moderna and Pfizer/BioNTech vaccines?

Different lipid formulations and stabilization Signup and view all the answers

Which group did both vaccine trials include as part of their studies?

Different age groups and co-morbidities Signup and view all the answers

What is a limitation of the clinical trials conducted for the mRNA vaccines?

Measurement of asymptomatic infections Signup and view all the answers

How quickly was Moderna able to design their vaccine construct after knowing the Spike sequence?

In 2 days Signup and view all the answers

What notable difference exists between the COVID-19 mRNA vaccines and traditional vaccines?

mRNA vaccines use genetic material to induce an immune response Signup and view all the answers

Which of the following statements is true regarding the efficacy of the COVID-19 mRNA vaccines?

Both vaccines showed approximately 95% efficacy against placebo Signup and view all the answers

Study Notes

mRNA Vaccines

Moderna and Pfizer designed mRNA vaccines that deliver mRNA coding for the spike protein of SARS-CoV-2
Both vaccines are highly effective, with over 95% efficacy against symptomatic COVID-19 infection
They required different storage conditions due to unique lipid formulations and mRNA stabilization methods

Viral Vector Vaccines

Replicating and non-replicating viral vectors can be used to deliver the spike protein gene to cells
AstraZeneca/Oxford developed an adenoviral vector vaccine, showing efficacy against COVID-19
Johnson & Johnson used an adenoviral vector vaccine, but its efficacy waned over time, prompting booster recommendations

Novavax Vaccine

A protein subunit vaccine containing the spike protein, lipids, adjuvants, and stabilizers
It received EUA in 2022 and was subsequently replaced by an updated version

COVID-19 Vaccine Effectiveness

Vaccines have prevented millions of hospitalizations and deaths in the U.S.
Immune response to the vaccine can wane over time as the virus evolves, necessitating annual updates.
New variants, like XBB-sublineage variants, account for the majority of circulating SARS-CoV-2 infections.
Vaccine effectiveness is measured through serum antibody neutralization assays and antigen-specific T cell responses.
Real-world vaccine efficacy measures protection against symptomatic and severe COVID-19 infection, including hospitalization and death.

Vaccine Development Challenges

Rapid development timeline led to accelerated clinical trials
Multiple vaccine candidates are being explored, aiming to improve efficacy and duration of protection
The presence of animal hosts, like bats, contributes to the complexity of achieving herd immunity
Misinformation and conspiracies surrounding vaccines continue to challenge public health efforts

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Description

This quiz covers the different types of COVID-19 vaccines, including mRNA and viral vector vaccines. It highlights their mechanisms, efficacy rates, and storage requirements. Explore the impact of these vaccines on public health and their effectiveness in preventing severe COVID-19 cases.