In the epidemiology of infectious diseases, the serial interval refers to the time interval between successive cases or case generations ("infector-infectee pairs") in an infection chain. The serial interval can be used to describe the temporal sequence of case generations very well. Above all, this epidemiological parameter is used to calculate the reproduction number (Reff). In April 2020, 312 transmission pairs were used to calculate the serial interval in Austria. This resulted in a mean of 4.46 days and a standard deviation of 2.63 days (Richter et al. (2020)). According to our current estimates, the mean value of the serial interval based on 250 transmission pairs studied in Austria is 3.37 days, which is about one day shorter than the mean value of 4.46 days calculated in spring 2020. The standard deviation of 1.83 days is also about one day shorter than a year ago.

L. RICHTER, F. TRAUNER, D. SCHMID, Department of Infectious Disease Epidemiology & Surveillance, AGES E. STADLOBER, Institute of Statistics, Graz University of Technology