Question 1: Vaccination involves introducing a substance containing weakened or inactive pathogens to stimulate the immune system. Explain the primary purpose of vaccination in disease prevention.

Answer: To stimulate the immune system to produce memory cells, providing long-term immunity against specific diseases.

Question 2: Describe how a vaccine activates the immune response to provide immunity.

Answer: A vaccine introduces antigens that stimulate the production of antibodies and memory cells, enabling the body to respond quickly if infected in future.

Question 1: Define 'herd immunity' and explain its significance in vaccination programmes.

Answer: Herd immunity occurs when a large proportion of the population is immune, reducing the spread of disease and protecting unvaccinated individuals.

Question 2: List two types of vaccines and briefly describe each.

Answer: Live attenuated vaccines contain weakened pathogens; inactivated vaccines contain killed pathogens.

Question 1: If a population of 10,000 people has a vaccination coverage of 85%, how many individuals are unvaccinated? Show your working.

Answer: Unvaccinated individuals = Total population x (1 - vaccination coverage) = 10,000 x (1 - 0.85) = 10,000 x 0.15 = 1,500

Question 1: Identify two safety precautions that should be taken during the administration of vaccines.

Answer: Monitoring for allergic reactions; using sterile equipment to prevent infection.

Question 2: Discuss one ethical issue associated with the distribution of vaccines in different countries.

Answer: An ethical issue is the unequal distribution of vaccines, which can lead to disparities in health outcomes between wealthy and poorer nations, raising questions of fairness and global health equity.

Question 1: A study reports that after vaccination, the proportion of people with immunity increased from 60% to 90% over a year. Explain what this data suggests about the effectiveness of the vaccination programme.

Answer: The increase suggests that the vaccination programme is highly effective in building immunity within the population.

Question 2: In a community with a vaccination coverage of 70%, explain why some individuals might still contract the disease.

Answer: Because not everyone is vaccinated, and some may not develop immunity despite vaccination, allowing the disease to spread.