Dr Anthony Fauci says 2,50,000 people have registered on a National Institutes of Heath website to take part in experimental vaccine trials. The study of the first vaccine involving 30,000 people began this week. The US government plans to launch studies of additional vaccines every month through the fall. Trials are pivotal for establishing the safety and effectiveness of the vaccines. Not all patients who volunteer for clinical trials are eligible to participate. Fauci is testifying before House lawmakers on the federal response to the pandemic, alongside the head of the Centers for Disease Control and Prevention and the government's testing czar. With hospitalisations and deaths on the rise, Fauci says Americans most again embrace public health basics such as social distancing and mask wearing.