This is simply untrue. For instance, in the late 90s/early 00s, the CDC inserted questions about defensive gun use into a national survey they routinely do on a test basis. After ~3 consecutive years of nearly replicating Kleck-level DGU rates, the experiment was dropped & results never published.

Another example is the lit review conducted at the order of President Obama in the wake of Sandy Hook—it almost entirely validated gun lobby talking points & was promptly buried. Regardless, any CDC employees who thought this research would violate the law could *easily* have avoided the project.