In the Community settings on YouTube, you can enable the feature which will hold certain comments for review, based on the keywords. Comments held for review are then hidden and are not visible under the video, until you decide to review them. This YouTube article here will explain how you can edit this setting.
We sync comments held for review in Agorapulse too, so that you can moderate them. All comments that have been held for review will have those Accept/Reject buttons available. You can decide whether you want to allow them to appear under your video, or not. By clicking Accept, you will allow the comment to be shown under the video, by clicking Reject it will stay hidden.