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Review
. 2020 Nov 23;10(11):e040263.
doi: 10.1136/bmjopen-2020-040263.

Rapid review of available evidence on the serial interval and generation time of COVID-19

John Griffin  1 , Miriam Casey  2 , Áine Collins  2   3 , Kevin Hunt  4 , David McEvoy  5 , Andrew Byrne  6 , Conor McAloon  7 , Ann Barber  2 , Elizabeth Ann Lane  2   3 , SImon More  2
Affiliations
Review

Rapid review of available evidence on the serial interval and generation time of COVID-19

John Griffin et al. BMJ Open. .

Abstract

The serial interval is the time between symptom onsets in an infector-infectee pair. The generation time, also known as the generation interval, is the time between infection events in an infector-infectee pair. The serial interval and the generation time are key parameters for assessing the dynamics of a disease. A number of scientific papers reported information pertaining to the serial interval and/or generation time for COVID-19.

Objective: Conduct a review of available evidence to advise on appropriate parameter values for serial interval and generation time in national COVID-19 transmission models for Ireland and on methodological issues relating to those parameters.

Methods: We conducted a rapid review of the literature covering the period 1 January 2020 and 21 August 2020, following predefined eligibility criteria. Forty scientific papers met our inclusion criteria and were included in the review.

Results: The mean of the serial interval ranged from 3.03 to 7.6 days, based on 38 estimates, and the median from 1.0 to 6.0 days (based on 15 estimates). Only three estimates were provided for the mean of the generation time. These ranged from 3.95 to 5.20 days. One estimate of 5.0 days was provided for the median of the generation time.

Discussion: Estimates of the serial interval and the generation time are very dependent on the specific factors that apply at the time that the data are collected, including the level of social contact. Consequently, the estimates may not be entirely relevant to other environments. Therefore, local estimates should be obtained as soon as possible. Careful consideration should be given to the methodology that is used. Real-time estimations of the serial interval/generation time, allowing for variations over time, may provide more accurate estimates of reproduction numbers than using conventionally fixed serial interval/generation time distributions.

Keywords: COVID-19; epidemiology; public health; virology.

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Conflict of interest statement

Competing interests: None declared.

Figures

Figure 1
Figure 1
Preferred Reporting Items for Systematic Reviews and Meta-Analyses for scoping reviews flow diagram.
Figure 2
Figure 2
A box plot summarising 34 estimates for serial interval or generation time from 28 papers. The purple triangles represent the means of the distributions. GT, generation time; SI, serial interval.
See this image and copyright information in PMC

References

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