TY - JOUR T1 - WHO adds Janssen vaccine to list of safe and effective emergency tools against COVID-19 JF - Saudi Medical Journal JO - Saudi Med J SP - 463 LP - 464 VL - 42 IS - 4 A2 - , Y1 - 2021/04/01 UR - http://smj.org.sa/content/42/4/463.abstract N2 - ER -