Gates stressed that the pandemic has interrupted the supply chains of drugs, including against AIDS, which risks disruptions which "could prevent hundreds of thousands of people from getting the treatments they need -- and not just in sub-Saharan Africa.""But I remain optimistic," he added. "We will defeat COVID-19 and we will continue to make strides against AIDS and other health crisis."He said the researchers are making great advances."Better diagnostic tools are being developed to identify those infected.