ANKARA, Aug 19 (Reuters) - Turkey will begin requiring negative COVID-19 test results and proofs of vaccination for some sectors, including from teachers as schools reopen next month and for domestic travel, President Tayyip Erdogan said on Thursday. Turkey has administered some 87 million vaccines against COVID-19, mainly Sinovac"s Coronavac and the Pfizer-BioNTech vaccine. Earlier this week, Ankara began Speaking after a cabinet meeting, Erdogan said the new requirements would be imposed for teachers, academics and thosw who attend social gathering such as concerts.