Social & Preventive Medicine In house with 9 susceptible individuals 1 gets infected and other two get infected after two days what is the secondary attack rate ? A 25% B 33% C 50% D 65% 💡 Explanation In house with 9 susceptible individuals 1 gets infected and other two get infected after two days what is the secondary attack rate ? ✓ Correct Answer: A. 25%