The article, “Oxford scientists defect to Imperial” (Nature Med. 6, 1070; 2000), contained factual errors which we are glad to correct: Professor Roy Anderson has not at any time been accused of sexual harassment, and meningococcus is a bacterium and not a virus. We should also clarify the point that Professor Geoffrey Smith was not a senior colleague of Anderson's at Oxford and that he made the decision to move institutions prior to Anderson. Our sincere apologies to the scientists concerned.