To the Editor.
—I have always believed that constructive critique is necessary as well as helpful. Dr Witte and colleagues chose from the very beginning to question the integrity of the work as well as the process. Regrettably, their recent article is further evidence of this.1We used the modified Miles and Miles2 method for assaying the induced VHP. None of the so-called blue tails were "intensely blue" as depicted by Witte et al in their article. Some of them did have a little color that could have easily come from the entry wound. But, as Witte and colleagues know, it did not have any consistent pattern. The tail color did not correlate with whether the animals were positive or negative. We provided new pictures for the evaluation by the Science reviewers.The artifacts that Witte et al have created are just that, artifacts. Our data, present in