Split Delimited Data in Columns into New Rows and keep all other data

HI,

I'm new to VBA and I am trying to split the data in my columns into separate rows while keeping the 1st column as well as the header intact. I have an existing code which allows me to split column B but I'm trying to edit the code such that I am able to split the data starting from Column B all the way to the last column. Can anyone kindly advice on how to do that? I've attached the excel file with the data as well as the below macro already in there.

Thank you and I sincerely appreciate the help!

____________________________________________________________________________________________________________________________

Option Explicit

Const ANALYSIS_ROW As String = "B"
Const DATA_START_ROW As Long = 1

Sub ReplicateData()
    Dim iRow As Long
    Dim lastrow As Long
    Dim ws As Worksheet
    Dim iSplit() As String
    Dim iIndex As Long
    Dim iSize As Long

    'Application.ScreenUpdating = False
    Application.Calculation = xlCalculationManual

    With ThisWorkbook
        .Worksheets("Concertina").Copy After:=.Worksheets("Concertina")
        Set ws = ActiveSheet
    End With

    With ws
        lastrow = .Cells(.Rows.Count, ANALYSIS_ROW).End(xlUp).Row
    End With


    For iRow = lastrow To DATA_START_ROW Step -1
        iSplit = Split(ws.Cells(iRow, ANALYSIS_ROW).Value2, ",")
        iSize = UBound(iSplit) - LBound(iSplit) + 1
        If iSize = 1 Then GoTo Continue

        ws.Rows(iRow).Copy
        ws.Rows(iRow).Resize(iSize - 1).Insert
        For iIndex = LBound(iSplit) To UBound(iSplit)
            ws.Cells(iRow, ANALYSIS_ROW).Offset(iIndex).Value2 = iSplit(iIndex)
        Next iIndex
Continue:
    Next iRow
    Application.CutCopyMode = False
    Application.Calculation = xlCalculationAutomatic
    'Application.ScreenUpdating = True
    
    
End Sub