Update clade_emergence_dates.tsv
@@ -25,3 +25,7 @@ Nextstrain_clade first_sequence
21K (Omicron) 2021-09-01
21L (Omicron) 2021-09-01
21M (Omicron) 2021-09-01
+22A (Omicron) 2021-12-01
+22B (Omicron) 2021-12-01
+22C (Omicron) 2021-12-01
+22D (Omicron) 2022-04-01
