Except for some sick kids, they never need to be vaccinated! If you calculate the efficacy of being a child (under 18) like they calculate the efficacy of vaccines*, you get this:

<blockquote>The efficacy of Pfizer against hospitalization is 88%.
The efficacy of youth against hospitalization is 86.6%

The efficacy of Pfizer against death is 95%.
The efficacy of youth against death is 99.7%.</blockquote>

We do not and should not shoot chemicals into a child's body without a good reason to do so. There is no good reason to give them any covid vaccine.

* formula for efficacy = [(rate in control group) - (rate in test group)]/(rate in control group)

Data from earlier this week, directly from CDC numbers:

Hospitalization rate in children per 100k = 55.5
Fatality rate in children per 100k = 0.74

Hospitalization rate in adults per 100k = 823
Fatality rate in adults per 100k = 211.6

** politico(dot)com/news/2021/09/17/cdc-study-finds-moderna-vaccine-is-best-at-preventing-covid-19-hospitalization-512565