You don’t “get into” a PhD program because of a GRE score. Although the weight varies by program, pretty much a GRE score can help you can make a cut (or be cut) but it is a filter metric, not a final thumbs up metric. Neither of the two PhD candidate selection committees that I have sat on were at Harvard, but I am hard pressed to believe that it would be different there.
The GRE is what it is. Your focus needs to be on your Statement of Purpose, and on giving your referees a good sense of what you are looking for from a PhD program and what they know of you that you think is relevant to your application.