What is serial interval?
- The serial interval is the duration between symptom onset of a primary case and symptom onset of secondary cases (contacts) generated by the primary case.
- In simple terms, the serial interval is the gap between the onset of Covid-19 symptoms in Person A and Person B, who is infected by Person A.
What does changes in serial interval indicate?
- The serial interval helps to gauge the effectiveness of infection control interventions besides indicating rising population immunity and forecast future incidence.
- Thus, the more quickly persons who contracted Covid-19 are identified and isolated, the shorter the serial interval becomes and cuts down opportunities for transmission of the virus.
- To manage serial interval, a robust system of contact tracing, quarantine, and isolation protocols should be in place.