Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| State (class) | Vacator | Reason for change | Successor | Date of successor's formal installation |
| --- | --- | --- | --- | --- |
| Georgia (2) | Richard Russell, Jr. (D) | Died January 21, 1971 | David H. Gambrell (D) | February 1, 1971 |
| Vermont (1) | Winston L. Prouty (R) | Died September 10, 1971 | Robert Stafford (R) | September 16, 1971 |
| Louisiana (2) | Allen J. Ellender (D) | Died July 27, 1972 | Elaine S. Edwards (D) | August 1, 1972 |
| Georgia (2) | David H. Gambrell (D) | Successor elected November 7, 1972 | Sam Nunn (D) | November 7, 1972 |
| Louisiana (2) | Elaine S. Edwards (D) | Successor elected November 13, 1972 | Bennett Johnston, Jr. (D) | November 14, 1972 |
Question:
Who is the vacator for the February 1, 1971 date of successor's formal installation?
Answer:
Richard Russell, Jr. (D)