In a stark shift of tone, US President Donald Trump appeared at his first Covid-19 press briefing in about three months, avoiding his usual upbeat and dismissive rhetoric about the pandemic as he encouraged the public to use face masks. The July 21, 2020 press briefing also included a warning that the pandemic “will probably, unfortunately, get worse before it gets better”. In a tweet posted the same day, Trump also called wearing masks a “patriotic act”, in sharp contrast to his remarks in…