I found this document https://www.astrazeneca.com/media-centre/press-releases/2020/azd1222-oxford-phase-iii-trials-interim-analysis-results-published-in-the-lan

I found this document https://www.astrazeneca.com/media-centre/press-releases/2020/azd1222-oxford-phase-iii-trials-interim-analysis-results-published-in-the-lancet.html https://www.astrazeneca.com/media-centre/press-releases/2020... which stated about the phase I/II trial that "Weekly COVID-19 PCR testing is performed". However, the phase II/III and phase III trials state "Suspected cases presenting with compatible symptoms were tested for virological confirmation by COVID-19 PCR" (slightly different wording in the two cases)