A team of researchers in The Netherlands will begin a clinical trial this week that will test whether a tuberculosis vaccine can boost the immune system to more effectively fight against the novel coronavirus. Researchers in three other countries will also soon begin the trials. The studies will test the vaccine on individuals at high risk of becoming infected, such as medical personnel and the elderly. The team of Dutch researchers will enlist 1,000 health care workers from eight hospitals to receive the vaccine. The study will ultimately test whether the tuberculosis vaccine, called Bacillus Calmette-Guérin (BCG), has the ability to fight against the novel coronavirus and lessen its impact on patients. Danish researchers Peter Aaby and Christine Stabell Benn previously found that BCG protects against roughly 30 percent of infections from any pathogen, however the World Health Organization assessed the study and rated its confidence in the findings as “very low.” Since then, several other researchers have built on the Danish study to widen the scope of understanding of how the vaccine can ramp up the immune system.