By Jenny Strasburg 



  LONDON--AstraZeneca PLC's chief executive said a Covid-19 vaccine it is developing with the University of Oxford could still be ready by the end of the year, despite the company pausing late-stage trials after a participant in the U.K. developed an unexplained illness. 


  Chief Executive Pascal Soriot said the progress of a safety review into the trial subject will determine the timetable for vaccine progress. He said, though, that he still expects a set of data from the trials that can be presented to regulators for approval by the end of the year. 


  "We could still have a vaccine by the end of this year, early next year," he told reporters during an online conference Thursday morning. 


  Mr. Soirot said that manufacturing capacity for the global distribution of the vaccine should be ready by early next year, and that the company intends on making the vaccine available to all regions of the world at the same time. AstraZeneca has inked deals with several governments, manufacturers and other institutions around the world to help it make and distribute its vaccine worldwide. 


  An independent committee is reviewing potential safety concerns related to the sick U.K. trial participant, which led to the trial pause. The vaccine, which AstraZeneca has licensed from Oxford, is one of the most advanced efforts in the West. Before the pause, the company said it might have enough data by next month to submit the vaccine to regulators for approval. 


  Mr. Soriot said the company doesn't have a diagnosis for the trial subject who fell ill. 


  "More tests are being done on the patient, the person, who developed the symptoms [...] You have to do a number of tests, and you have to take time." 


  The U.K. study of the vaccine was paused once before, in July, according to an Oxford spokesman. The university declined to discuss specifics, other than that there were no ongoing concerns as a result of the event. Material sent to study subjects in July indicated the pause was triggered by symptoms in a volunteer of a neurological disorder known as transverse myelitis. But AstraZeneca said Wednesday the case turned out to be multiple sclerosis unrelated to the vaccine and the testing resumed. 


  AstraZeneca had been conducting a large trial in the U.K., and had just started another large, late-stage trial in the U.S., which aims to enroll up to 30,000 people. Both trials were aimed at determining whether the vaccine safely protects people from Covid-19. AstraZeneca also had been testing the vaccine in countries including South Africa and Brazil. 


  Write to Jenny Strasburg at jenny.strasburg@wsj.com