Dear Mr Major (Clarity),

We analysed data up to one year and up to three years prior to the start of RBCT culling in trial areas. We are not aware of any analyses of data up to 10 or 20 years prior to culling for these areas. If these early data were useful in explaining additional variation observed in the RBCT incidence data (which seems unlikely given the large time lag), they would be expected to increase the precision of our parameter estimates.

Christl A. Donnelly1*, Helen E. Jenkins2, Rosie Woodroffe3

1 Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
2 Brigham and Women's Hospital and Harvard Medical School, Boston, USA
3 Institute of Zoology, London, United Kingdom

* E-mail: c.donnelly@imperial.ac.uk