Question 1: Define Measles and describe the primary mode of transmission.

Answer: Measles is a highly contagious viral infection transmitted primarily through respiratory droplets when an infected person coughs or sneezes.

Question 2: Explain how the Measles virus affects the immune system and causes symptoms.

Answer: The Measles virus infects cells of the immune system, leading to immune suppression, which causes symptoms like rash, fever, and cough, and increases susceptibility to other infections.

Question 3: What is herd immunity, and why is it important in controlling Measles outbreaks?

Answer: Herd immunity occurs when a high percentage of the population is vaccinated, reducing the spread of the virus and protecting unvaccinated individuals.

Question 1: If the total population of a town is 10,000 and 95% are vaccinated against Measles, how many people are unvaccinated? Show your calculation.

Answer: Unvaccinated = Total population - Vaccinated population = 10,000 - (95/100) * 10,000 = 10,000 - 9,500 = 500 people

Question 2: The basic reproduction number (R0) for Measles is approximately 12-18. Explain what R0 indicates and calculate the average number of people one infected person can infect in a fully susceptible population.

Answer: R0 indicates the average number of secondary infections produced by a single infected individual in a fully susceptible population. For Measles, on average, one person can infect approximately 15 people.

Question 1: Design a simple experiment to test the effectiveness of the MMR vaccine in preventing Measles infection. Include variables and safety precautions.

Answer: An experiment could involve two groups of laboratory animals or cell cultures: one vaccinated with the MMR vaccine and one unvaccinated. Both groups are then exposed to the Measles virus under controlled conditions. The independent variable is vaccination status; the dependent variable is infection rate. Safety precautions include handling the virus in a biosafety cabinet, wearing protective gear, and proper disposal of infectious materials.

Question 2: Identify three variables that should be controlled during the experiment and explain why.

Answer: Variables to control include: 1) Age and health status of subjects to ensure consistency; 2) Exposure time to the virus to standardize infection conditions; 3) Environment conditions like temperature and humidity to prevent external influences on infection outcomes.

Question 1: In a community of 5,000 people, 3,800 are vaccinated against Measles. During an outbreak, 50 unvaccinated individuals contracted Measles, while only 5 vaccinated individuals did. Calculate the attack rate for both groups and interpret the results.

Answer: Attack rate for unvaccinated = (Number of cases among unvaccinated / Total unvaccinated) * 100 = (50 / 1200) * 100 ≈ 4.17% Attack rate for vaccinated = (Number of cases among vaccinated / Total vaccinated) * 100 = (5 / 3800) * 100 ≈ 0.13% Interpretation: The attack rate is significantly higher in unvaccinated individuals, indicating the effectiveness of the vaccine.

Question 1: Discuss how the development of the MMR vaccine has impacted the incidence of Measles globally.

Answer: The development of the MMR vaccine has drastically reduced the incidence of Measles worldwide, leading to the near-eradication of the disease in many countries. Vaccination programs have increased herd immunity, preventing outbreaks, and saving countless lives. Continued vaccination efforts are essential to prevent resurgence, especially in areas with low coverage.

Question 2: Explain how vaccine hesitancy can affect Measles control efforts and suggest strategies to improve vaccine uptake.

Answer: Vaccine hesitancy can reduce herd immunity, leading to outbreaks. Strategies to improve uptake include public education campaigns, addressing misconceptions, involving community leaders, and ensuring easy access to vaccines.