diff --git a/HowBadIsMyBatch.ipynb b/HowBadIsMyBatch.ipynb
index 87410edc323..271895ee9be 100644
--- a/HowBadIsMyBatch.ipynb
+++ b/HowBadIsMyBatch.ipynb
@@ -91,8 +91,7 @@
     "# FK-TODO: DRY with createAndFilterDataFrameFromFiles()\n",
     "def createDataFrameSevereEffectsFromFiles(dataDir, dose):\n",
     "    return createDataFrameSevereEffectsFromDescrs(\n",
-    "        # FK-TODO: reactivate: [readVaersDescr(dataDir, \"2021\"), readVaersDescr(dataDir, \"2022\")],\n",
-    "        [readVaersDescr(dataDir, \"2022\")],\n",
+    "        [readVaersDescr(dataDir, \"2021\"), readVaersDescr(dataDir, \"2022\")],\n",
     "        dose)"
    ]
   },
@@ -115,15 +114,20 @@
     "    }\n",
     "    return pd.concat(batchCodeTableDict, axis = 'columns').replace(to_replace = np.nan, value = 0)\n",
     "\n",
-    "def getManufacturerOfBatchCode(df, batchCode):\n",
-    "    return df[df['VAX_LOT'] == batchCode].iloc[0]['VAX_MANU']\n",
+    "def createManufacturerByBatchCodeTable(df):\n",
+    "    manufacturerByBatchCodeTable = df[['VAX_LOT', 'VAX_MANU']]\n",
+    "    manufacturerByBatchCodeTable = manufacturerByBatchCodeTable.drop_duplicates(subset = ['VAX_LOT'])\n",
+    "    return manufacturerByBatchCodeTable.set_index('VAX_LOT')\n",
+    "\n",
+    "def createCompanyByBatchCodeTable(df):\n",
+    "    return createManufacturerByBatchCodeTable(df).rename(columns = {\"VAX_MANU\": \"COMPANY\"})\n",
     "\n",
     "def createSevereEffectsBatchCodeTable(df):\n",
     "    def filterDataFrame(df, col):\n",
-    "        return df[df[col] == 'Y'][['VAX_LOT']]\n",
+    "        return df[df[col] == 'Y']['VAX_LOT']\n",
     "\n",
     "    batchCodeTableDict = {\n",
-    "        'ADRs': df[['VAX_LOT']].value_counts(),\n",
+    "        'ADRs': df['VAX_LOT'].value_counts(),\n",
     "        'DEATHS': filterDataFrame(df, 'DIED').value_counts(),\n",
     "        'DISABILITIES': filterDataFrame(df, 'DISABLE').value_counts(),\n",
     "        'LIFE THREATENING ILLNESSES': filterDataFrame(df, 'L_THREAT').value_counts(),\n",
@@ -131,9 +135,14 @@
     "        'EMERGENCY ROOM OR DOCTOR VISITS': filterDataFrame(df, 'ER_VISIT').value_counts()\n",
     "    }\n",
     "    batchCodeTable = pd.concat(batchCodeTableDict, axis = 'columns')\n",
-    "    batchCodeTable['COMPANY'] = batchCodeTable.apply(\n",
-    "            lambda row: getManufacturerOfBatchCode(df, row.name[0]),\n",
-    "            axis = 'columns')\n",
+    "    # add Company column:\n",
+    "    batchCodeTable = pd.merge(\n",
+    "            batchCodeTable,\n",
+    "            createCompanyByBatchCodeTable(df),\n",
+    "            how = 'left',\n",
+    "            left_index = True,\n",
+    "            right_index = True,\n",
+    "            validate = 'one_to_one')\n",
     "    return batchCodeTable.replace(to_replace = np.nan, value = 0)\n"
    ]
   },
@@ -434,14 +443,14 @@
     "        batchCodeTableExpected = pd.DataFrame(\n",
     "            data = {\n",
     "                'ADRs': [1, 1],\n",
-    "                'DEATHS': [0, 1],\n",
-    "                'DISABILITIES': [1, 0],\n",
-    "                'LIFE THREATENING ILLNESSES': [0, 1],\n",
-    "                'HOSPITALISATIONS': [0, 1],\n",
+    "                'DEATHS': [1, 0],\n",
+    "                'DISABILITIES': [0, 1],\n",
+    "                'LIFE THREATENING ILLNESSES': [1, 0],\n",
+    "                'HOSPITALISATIONS': [1, 0],\n",
     "                'EMERGENCY ROOM OR DOCTOR VISITS': [1, 1],\n",
-    "                'COMPANY': ['PFIZER\\BIONTECH', 'MODERNA']\n",
+    "                'COMPANY': ['MODERNA', 'PFIZER\\BIONTECH']\n",
     "            },\n",
-    "            index = pd.MultiIndex.from_arrays([['025L20A', '037K20A']], names = ('VAX_LOT',)))\n",
+    "            index = pd.Index(['037K20A', '025L20A']))\n",
     "        assert_frame_equal(batchCodeTable, batchCodeTableExpected, check_dtype = False)\n",
     "\n",
     "    def createDataFrame(self, index, columns, data, dtypes = {}):\n",