Your selective reading of either study and analysis of the statistics and conclusions of the study are not valid.
”Our data support vaccine protection against severe disease among children 5-11 years, but suggest rapid loss of protection against infection, in the Omicron variant era. Should such findings be replicated in other settings, review of the dosing schedule for children 5-11 years appears prudent. At this time, efforts to increase primary vaccination coverage in this age group, which remains <25% nationally, should continue. Given rapid loss of protection against infections, these results highlight the continued importance of layered protections, including mask wearing, for children to prevent infection and transmission.”
The graph actually comes from a third party pharmaceutical study.
And from the editorial comments from your quoted article,
”The encouraging message should be that although vaccine protection for children and adolescents was lower in the Omicron era than with previous variants and that such protection wanes rapidly, vaccine effectiveness against hospitalization remains high and booster doses confer additional protection.”
ref:
Protecting Children Against Omicron