News Health & Medicine HHS says new vaccines should be tested against placebos. They already are Redundant testing could reduce protection from infectious diseases Vaccines are already rigorously assessed for safety and efficacy, both before and after they’re available to the public, health experts say. Jose Luis Pelaez Inc/Getty Images By McKenzie Prillaman 1 hour ago The U.S. Department of Health and Human Services’ potential plan to alter vaccine testing has baffled health experts, who worry it could reduce protection from infectious diseases and waste time and money. The agency said in a recent statement that it intends to require all new vaccines be compared with inert placebos, like saline shots, in clinical trials. HHS claims the move will increase transparency and is a “radical departure from past practices,” according to a statement to Science News from an agency spokesperson. Sign up for our newsletter We summarize the week's scientific breakthroughs every Thursday.