Classen proposes that vaccines cause diabetes by causing the release of interferons, causing an autoimmune state leading to immune-mediated type 1 diabetes, and he is quoted on many anti-vaccine websites, such as that of the National Vaccine Information Center. His work has been criticized, for example, journalist Amy Wallace wrote that the vaccine-diabetes link "...relies on the flawed work of one doctor [Classen], who gathered data on a slew of vaccines and failed to follow standard study protocols. No other study — including those using the same data — could reproduce the results." Independent studies that have investigated the potential link between vaccines and diabetes include one, published by Frank DeStefano, which "did not find an increased risk of type 1 diabetes associated with any of the routinely recommended childhood vaccines." DeStefano et al. also noted that another study of over 100,000 children examined the potential connection between Hib vaccines and diabetes and found no association between the two. Similarly, the Australian National Centre for Immunisation Research and Surveillance examined Classen's studies and wrote that "Other researchers who have studied the issue have not verified Dr Classen’s findings."
