Basic Concepts of Herd Immunity
- What is herd immunity?
- A) Immunity developed after natural infection
- B) Protection of susceptible individuals due to a high proportion of immune individuals in a population
- C) Immunity acquired through vaccination only
- D) A type of genetic immunity
- Which of the following is essential for herd immunity?
- A) High vaccine coverage
- B) High birth rates
- C) Increased pathogen virulence
- D) Widespread antibiotic use
- Herd immunity primarily protects:
- A) Only vaccinated individuals
- B) Entire population, including unvaccinated individuals
- C) Only newborns
- D) Only individuals who have had a previous infection
- Which of the following diseases has been eradicated globally due to herd immunity?
- A) Polio
- B) Smallpox
- C) Measles
- D) Tuberculosis
- Herd immunity is effective against:
- A) Infectious diseases
- B) Genetic disorders
- C) Autoimmune diseases
- D) Metabolic diseases
- The concept of herd immunity was first described in which type of disease?
- A) Bacterial infections
- B) Viral infections
- C) Parasitic infections
- D) Fungal infections
Threshold and Coverage
- Herd immunity threshold refers to:
- A) The percentage of immune individuals needed to prevent disease spread
- B) The percentage of infected individuals in an outbreak
- C) The duration of vaccine protection
- D) The total number of individuals vaccinated
- The herd immunity threshold for measles is approximately:
- A) 60%
- B) 70%
- C) 80%
- D) 95%
- Which factor does not affect the herd immunity threshold?
- A) Population density
- B) Vaccine efficacy
- C) Mutation rate of the pathogen
- D) Air pollution levels
- If a disease has a basic reproduction number (R₀) of 5, what is the approximate herd immunity threshold?
- A) 20%
- B) 60%
- C) 80%
- D) 90%
- Which of the following increases the herd immunity threshold?
- A) A more contagious pathogen
- B) Improved healthcare access
- C) Lower birth rates
- D) Reduced travel
Vaccination and Herd Immunity
- Herd immunity through vaccination works best when:
- A) A vaccine provides lifelong immunity
- B) A vaccine requires multiple booster doses
- C) Only symptomatic individuals are vaccinated
- D) People avoid vaccination
- Which type of vaccine is most effective in achieving herd immunity?
- A) Live attenuated vaccines
- B) Inactivated vaccines
- C) Toxoid vaccines
- D) mRNA vaccines
- Which disease is close to eradication due to herd immunity from vaccination?
- A) Polio
- B) Malaria
- C) HIV/AIDS
- D) Influenza
- A decrease in vaccination rates can lead to:
- A) Strengthened herd immunity
- B) Increased disease outbreaks
- C) Permanent immunity in children
- D) Elimination of vaccine-preventable diseases
- Which of the following populations benefits most from herd immunity?
- A) Individuals with strong immune systems
- B) Newborns and immunocompromised individuals
- C) Adults with prior infections
- D) People living in rural areas
- Why is herd immunity not effective against tetanus?
- A) Tetanus is not contagious
- B) The vaccine does not provide lifelong immunity
- C) The pathogen mutates frequently
- D) Herd immunity only works for viral diseases
- The concept of herd immunity does not apply to:
- A) Rabies
- B) Influenza
- C) COVID-19
- D) Pertussis
Epidemiology and Public Health
- Which of the following public health strategies supports herd immunity?
- A) Mass vaccination campaigns
- B) Use of antibiotics
- C) Isolation of infected individuals
- D) Genetic screening
- In a pandemic, herd immunity can be achieved by:
- A) Natural infection
- B) Vaccination
- C) Both A and B
- D) None of the above
- Which of the following challenges herd immunity efforts?
- A) Vaccine hesitancy
- B) High vaccine efficacy
- C) Low pathogen mutation rates
- D) Universal healthcare
- The “basic reproduction number” (R₀) refers to:
- A) The number of people infected by one infected individual in a susceptible population
- B) The number of vaccine doses required for immunity
- C) The percentage of the population vaccinated
- D) The number of deaths caused by an infection
- Why is herd immunity difficult to achieve for the flu?
- A) The flu virus mutates frequently
- B) Flu vaccines are ineffective
- C) The flu is not contagious
- D) The flu only affects older adults
- Which of the following reduces herd immunity?
- A) Increased travel and migration
- B) Mass vaccination programs
- C) Strong health policies
- D) Improved sanitation
Ethical and Social Considerations
- Ethical concerns about herd immunity arise when:
- A) Vaccination is made mandatory
- B) Governments fund vaccination programs
- C) Individuals refuse vaccination, relying on others to be vaccinated
- D) Scientists develop new vaccines
- “Free-riding” in herd immunity means:
- A) Relying on others to be vaccinated without getting vaccinated oneself
- B) Using public transportation to avoid exposure
- C) Developing natural immunity through infection
- D) Having a higher resistance to diseases naturally
- Which of the following groups cannot contribute to herd immunity?
- A) Infants
- B) Elderly individuals
- C) Healthcare workers
- D) School-aged children
- Herd immunity against COVID-19 was initially difficult to achieve because:
- A) The virus had a high mutation rate
- B) The vaccine was unavailable initially
- C) Not enough people were vaccinated early
- D) All of the above
Miscellaneous
- Which of the following factors increases herd immunity?
- A) High vaccine uptake
- B) Increased antibiotic resistance
- C) Poor sanitation
- D) Vaccine misinformation
- Which disease was nearly eradicated but resurged due to declining vaccination rates?
- A) Measles
- B) Smallpox
- C) Ebola
- D) HIV