Applications providing ultra-low-latency video streaming to large audiences require fast and efficient packet-loss repair. Previous methods utilizing keyframe injection (such as the High Efficiency Streaming Protocol) have a low impact on the repaired stream quality, but at a cost of a significant bitrate spike during repair. In this paper, we propose injecting P-frames for packet-loss repair of ultra-low-latency streaming. We implemented (open-source) and evaluated our approach in both H.265/HEVC and H.266/VVC standards. Through extensive evaluations, we demonstrate that the proposed solution significantly reduces bitrate overhead while maintaining a similar or lower decrease in quality compared to existing packet-loss-repair techniques. Overall, the proposed approach offers a promising solution to ensure reliable packet-loss recovery, efficient resource utilization, and a high-quality streaming experience.