Clinical trials of one of the most advanced experimental Covid-19 vaccines resumed Saturday after a brief safety pause, as infection numbers continued to march upward in countries across the globe. The world’s hopes for a reprieve from the pandemic were dealt a blow earlier in the week when pharmaceutical company AstraZeneca and Oxford University announced they had “voluntarily paused” their vaccine trial after a UK volunteer developed an unexplained illness. But on Saturday the trial was given the all clear by British regulators to resume following a safety review. The company also announced it was resuming clinical trials in Brazil next Monday after being given the green light there as well. The global death toll from the coronavirus has risen to 916,000 with 28.5 million infections, while France and the United Arab Emirates posted grim new milestones for daily infections on Saturday. And with billions still suffering from the fallout of the pandemic, a worldwide race for a vaccine is underway, with nine companies already in late-stage Phase 3 trials.Even during the pause, AstraZeneca said it remained hopeful that the vaccine could still be available “by the end of this year, early next year”. Oxford University said that “in large trials such as this, it is expected that some participants will become unwell and every case must be carefully evaluated”.Charlotte Summers, lecturer in intensive care medicine at Cambridge University, said the pause showed the researchers’ commitment “to putting safety at the heart of their development programme.” “To tackle the global Covid-19 pandemic, we need to develop vaccines and therapies that people feel comfortable using, therefore it is vital to maintaining public trust that we stick to the evidence and do not draw conclusions before information is available,” she said. Backlash That public trust will be crucial to convincing a public that is impatient for a vaccine — and in some corners sceptical.Among the impatient is US President Donald Trump, who has been accused by rival Joe Biden of “undermining public confidence” by regularly raising the possibility that a vaccine will be ready before November’s election.The Republican president is under pressure as the US toll continues to rise, nearing 6.5 million cases on Saturday with more than 193,000 deaths — by far the most in either measure in the world.