It is widespread opinion that hydrogen reionization is mainly driven by primeval star-forming galaxies, with high-zactive galactic nuclei (AGNs) having a minor role. Recent observations, however, challenge this notion, indicating a number of issues related to a galaxy-driven reionization scenario. We provide here an updated assessment of the space density of relatively faint (M-1450 similar to -22.5) AGNs atz(spec) similar to 5.5 in order to improve the estimate of the photoionization rate contribution from accreting supermassive black holes. Exploiting deep UV rest-frame ground-based spectra collected at the Very Large Telescope on the CANDELS/GOODS-South field and deep Chandra X-ray images in the CANDELS/GOODS-North and EGS areas, we find two relatively bright (M-1450 similar to -22.5) AGNs atz(spec) similar to 5.5. We derive an AGN space density of phi = 1.29 x 10(-6)cMpc(-3)atz similar to 5.5 andM(1450) similar to -22.5 by simply dividing their observed number by the cosmological volume in the range 5.0 z < 6.1. Our estimate does not consider corrections for incompleteness; therefore, it represents a lower limit, although uncertainties due to cosmic variance can still be significant. This value supports a high space density of AGNs atz > 5, in contrast with previous claims mostly based on standard color selection, possibly affected by significant incompleteness. Our estimate for the AGN photoionization rate atz similar to 5.5 is in agreement with the observed values at similar redshifts, which are needed to keep the intergalactic medium highly ionized. Upcoming James Webb Space Telescope and giant ground-based telescopes observations will improve the study of high-zAGNs and their contribution to the reionization of the universe.