diff --git a/src/SymptomsByBatchcodesTableFactory.py b/src/SymptomsByBatchcodesTableFactory.py
index d61b8b1b1fe..657a80942bd 100644
--- a/src/SymptomsByBatchcodesTableFactory.py
+++ b/src/SymptomsByBatchcodesTableFactory.py
@@ -5,23 +5,24 @@ class SymptomsByBatchcodesTableFactory:
 
     @staticmethod
     def createSymptomsByBatchcodesTable(VAERSVAX, VAERSSYMPTOMS):
+        index_columns = ['VAX_LOT1', 'VAX_LOT2']
         return pd.merge(
-            SymptomsByBatchcodesTableFactory._get_VAERSVAX_WITH_VAX_LOTS(VAERSVAX),
+            SymptomsByBatchcodesTableFactory._get_VAERSVAX_WITH_VAX_LOTS(VAERSVAX, index_columns),
             SymptomsByBatchcodesTableFactory._getSymptomsTable(VAERSSYMPTOMS),
-            on = 'VAERS_ID').set_index(['VAX_LOT1', 'VAX_LOT2'])[['SYMPTOMS']]
+            on = 'VAERS_ID').set_index(index_columns)[['SYMPTOMS']]
     
     @staticmethod
-    def _get_VAERSVAX_WITH_VAX_LOTS(VAERSVAX):
+    def _get_VAERSVAX_WITH_VAX_LOTS(VAERSVAX, index_columns):
         return pd.concat(
-            [VAERSVAX, SymptomsByBatchcodesTableFactory._getVaxLotsTable(VAERSVAX)],
-            axis='columns').reset_index().drop_duplicates(subset=['VAERS_ID', 'VAX_LOT1', 'VAX_LOT2'])
+            [VAERSVAX, SymptomsByBatchcodesTableFactory._getVaxLotsTable(VAERSVAX, index_columns)],
+            axis='columns').reset_index().drop_duplicates(subset = ['VAERS_ID'] + index_columns)
 
     @staticmethod
-    def _getVaxLotsTable(VAERSVAX):
+    def _getVaxLotsTable(VAERSVAX, index_columns):
         VAX_LOT_LIST_Table = VAERSVAX.groupby("VAERS_ID").agg(VAX_LOT_LIST = pd.NamedAgg(column = 'VAX_LOT', aggfunc = list))
         return pd.DataFrame(
             [fill(VAX_LOTS, 2, str(np.nan)) for VAX_LOTS in VAX_LOT_LIST_Table['VAX_LOT_LIST'].tolist()],
-            columns = ['VAX_LOT1', 'VAX_LOT2'],
+            columns = index_columns,
             index = VAX_LOT_LIST_Table.index)
 
     @staticmethod
diff --git a/src/SymptomsByBatchcodesTableFactoryTest.py b/src/SymptomsByBatchcodesTableFactoryTest.py
index a328f60c45a..c18528e4766 100644
--- a/src/SymptomsByBatchcodesTableFactoryTest.py
+++ b/src/SymptomsByBatchcodesTableFactoryTest.py
@@ -61,9 +61,9 @@ class SymptomsByBatchcodesTableFactoryTest(unittest.TestCase):
     def test_createSymptomsByBatchcodesTable_two_patients_same_symptoms(self):
         # Given
         VAERSVAX = TestHelper.createDataFrame(
-            columns = ['VAX_TYPE', 'VAX_MANU',        'VAX_LOT', 'VAX_DOSE_SERIES'],
-            data = [  ['COVID19',  'JANSSEN',         'EW0175',  '1'],
-                      ['COVID19',  'JANSSEN',         'EW0175',  '1']],
+            columns = ['VAX_TYPE', 'VAX_MANU', 'VAX_LOT', 'VAX_DOSE_SERIES'],
+            data = [  ['COVID19',  'JANSSEN',  'EW0175',  '1'],
+                      ['COVID19',  'JANSSEN',  'EW0175',  '1']],
             index = pd.Index(
                     name = 'VAERS_ID',
                     data=[