But evidence released earlier this year by Cochrane Collaboration, a London-based nonprofit, shows that a significant amount of negative data from the drug's clinical trials were hidden from the public. The Food and Drug Administration (FDA) knew about it, but the medical community did not; the U.S. Centers for Disease Control and Prevention (CDC), which doesn't have the same access to unpublished data as regulators, had recommended the drug without being able to see the full picture. When results from those unpublished trials finally did emerge, they cast doubt over whether Tamiflu is as effective as the manufacturer