Technically true. The best you can do is make an educated guess based on the available data. However, I believe trials have been ongoing for a while now for children under 12 so they should have some pretty good data by now.
"The data summarized from this Phase 2/3 study, which is enrolling children 6 months to 11 years of age, was for 2,268participants who were 5 to 11 years of age and received a 10 µg dose level in a two-dose regimen. In the trial, the SARS-CoV-2–neutralizing antibody geometric mean titer (GMT) was 1,197.6 (95% confidence interval [CI, 1106.1, 1296.6]), demonstrating strong immune response in this cohort of children one month after the second dose. This compares well (was non-inferior) to the GMT of 1146.5 (95% CI: 1045.5, 1257.2) from participants ages 16 to 25 years old, used as the control group for this analysis and who were administered a two-dose regimen of 30 µg. Further, the COVID-19 vaccine was well tolerated, with side effects generally comparable to those observed in participants 16 to 25 years of age."