Trials of a Covid-19 vaccine being developed by AstraZeneca and Oxford University will continue, following a review into the death of a volunteer in Brazil. Brazil’s health authority has given no details about the death, citing confidentiality protocols. Oxford University said a “careful assessment” had revealed no safety concerns. The BBC understands that the volunteer did not receive the vaccine. Only around half the volunteers in the trial are given the actual Oxford University Covid-19 vaccine. The second group are being given an existing licensed vaccine for meningitis. Neither the participants nor their families know which vaccine they are being given. This enables the researchers to compare the results for the two groups in order to measure whether the vaccine  is effective.(BBC)…[+]