The dollar was up on Thursday morning in Asia, reversing earlier losses as investors turn towards the safe-haven asset. Wednesday’s hopes for a COVID-19 vaccine dimmed, with doubts surfacing over the efficacy of Moderna's potential COVID-19 vaccine in immunizing against the disease. Moderna said on Tuesday that all 45 volunteers participating in a study for the vaccine developed high levels of virus-killing antibodies. Meanwhile, U.S. President Donald Trump privately ruled out further sanctions against Chinese entities involved in enacting Hong Kong’s national security laws on Wednesday, attempting to diffuse escalating U.S.-China tensions. But tensions remain in place, with China threatening to retaliate after Trump also stripped Hong Kong of its special trading privileges and signed an executive order for initial sanctions on Tuesday.