Social & Preventive Medicine Which among the following statement is TRUE about ‘serial interval’? A Time interval between invasion of infection and appearance of first sign or symptom B Time between onset of primary case and secondary case C Interval of time between receipt of infection by a host and maximum infectivity D Time in which infectious agent is transferred from one host to another 💡 Explanation Which among the following statement is TRUE about 'serial interval'? ✓ Correct Answer: B. Time between onset of primary case and secondary case