claim: astrazeneca covid-19 vaccine study is put on!
evidence_1: a spokesperson for astrazeneca, a frontrunner in the race for a covid-19 vaccine, said in a statement that the companys standard review process triggered a pause to vaccination to allow review of safety data. in a follow-up statement, astrazeneca said it initiated the study hold.", "astrazenecas is the first phase 3 covid-19 vaccine trial known to have been put on hold.")