The head of the National Institutes of Health (NIH) will serve his last day on Dec. 19, the Biden administration announced Thursday. Dr. Francis Collins, the NIH commissioner, previously announced he was stepping down but the exact date he would resign was unclear. The Department of Health and Human Services, which includes the NIH, said Dr. Lawrence Tabak will replace Collins. Health Secretary Xavier Becerra tapped Tabak to serve as acting director of the agency until further notice. The NIH commissioner is a Senate-confirmed post. President Joe Biden will need to choose a permanent successor to Collins down the road. Tabak, who has a dental degree and a Ph.D., “has a deep grasp of the most pressing scientific issues confronting our nation, he has earned respect across NIH as a thoughtful and strategic manager and is committed to building a healthier and more equitable America,” Becerra said in a statement. …