Private Sub CommandButton1_Click()
Dim sh As Object
Dim vak As Variant, i As Integer
vak = 0
For Each sh In ThisWorkbook.Worksheets
  If sh.Name <> "СВОД" Then
  For i = 1 To sh.Columns(1).SpecialCells(xlLastCell).Row
    If LCase(sh.Cells(i, 1).Value) Like ["*вакансия*"] Then
     vak = vak + sh.Cells(i, 3).Value
    End If
  Next
   Cells(28, 3).Value = vak
  End If
Next
End Sub

Sub ertert()
Dim r As Range, adr$, wsh As Worksheet, i!
On Error Resume Next: Err.Clear
For Each wsh In ThisWorkbook.Worksheets
       If Not wsh Is ActiveSheet Then
           With wsh.UsedRange.Columns(1)
               Set r = .Find("вакансия")
               If Not r Is Nothing Then
                   adr = r.Address
                   Do
                       i = i + r(1, 3)
                       If Err Then Err.Clear: MsgBox "Проверьте ячейку " & _
                      r.Address & " на листе " & wsh.Name, 64
                       Set r = .FindNext(r)
                   Loop While r.Address <> adr
               End If
           End With
       End If
Next wsh
Range("C28").Value = i
End Sub