1 <p>Reference:
<a href=
"https://en.wikipedia.org/wiki/Serial_interval" target=
"_blank"><em>Wikipedia
</em></a>
3 The serial interval (SI) is not one of the estimators. It is a parameter required by most of the estimators, and can
4 also be estimated by some of them (if not specified).
7 The SI is defined as the average time between successive infections in a chain of transmission (i.e., the time between
8 the infection of an infected individual and their subsequent transmissions).