Social & Preventive Medicine Virulence of a biological agent is defined as ? A Ability of the agent to invade and multiply in host B Propoion of clinical cases resulting in severe clinical manifestation C Ability of the agent to induce a clinically apparent illness D Propoion of clinical cases in a virgin population 💡 Explanation Virulence of a biological agent is defined as ? ✓ Correct Answer: B. Propoion of clinical cases resulting in severe clinical manifestation