ed , ▁the ▁effective ▁reprodu ction ▁number ▁R ▁   ▁continued ▁to ▁play ▁a ▁major ▁role . ▁In ▁its ▁daily ▁bullet ins ▁of ▁ 2 6 – 2 8 ▁April , ▁the ▁Robert ▁Koch ▁Institute ▁( R K I ) ▁estimated ▁the ▁value ▁of ▁R ▁as ▁ 0 . 9 , ▁ 1 . 0 , ▁and ▁ 0 . 9 ▁respectively ; ▁it ▁had ▁been ▁as ▁low ▁as ▁ 0 . 7 ▁in ▁mid - A pril . ▁On ▁ 2 8 ▁April , ▁R K I ▁president ▁Wiel er ▁clar ified ▁that ▁the ▁ 2 7 ▁April ▁value ▁had ▁been ▁rounded ▁up ▁from ▁a ▁value ▁of ▁ 0 . 9 6 . ▁The ▁respective ▁upper ▁end - points ▁of ▁the ▁confidence ▁intervals ▁( at ▁the ▁ 9 5 ▁per ▁cent ▁level ) ▁for ▁the ▁estimates ▁of ▁R ▁were ▁ 1 . 1 , ▁ 1 . 1 , ▁and ▁ 1 . 0 . ▁▁ ▁At ▁the ▁ 2 8 ▁April ▁press ▁conference , ▁Wiel er ▁also ▁war ned ▁of ▁pin ning ▁too ▁many ▁expect ations ▁on ▁a ▁single ▁indicator ▁such ▁as ▁R , ▁as ▁this ▁was ▁" only ▁one ▁index ▁among ▁many ”. ▁He ▁appe aled ▁to ▁the ▁public ▁to ▁apply ▁physical ▁dist ancing ▁even ▁as ▁the ▁federal ▁and ▁state ▁govern ments ▁began ▁to ▁relax ▁restrictions ▁on ▁social ▁movement , ▁in ▁order ▁to ▁" pres erve " ▁the ▁success ▁that ▁had ▁been ▁achieved ▁to ▁date ▁in ▁the ▁fighting ▁the ▁pan demic . ▁ ▁On ▁ 1 ▁May , ▁traditional ▁demonstr