PT - JOURNAL ARTICLE ED - , TI - Statement on the update of WHO’s working definitions and tracking system for SARS-CoV-2 variants of concern and variants of interest DP - 2023 Apr 01 TA - Saudi Medical Journal PG - 427--427 VI - 44 IP - 4 4099 - http://smj.org.sa/content/44/4/427.short 4100 - http://smj.org.sa/content/44/4/427.full SO - Saudi Med J2023 Apr 01; 44