Yes, even keiki who are vaccinated should wear masks when indoors or in crowded settings with people from outside their household.

COVID-19 vaccines are very effective in preventing severe illness, but they do not always prevent infection.

Research confirms masks help keep keiki and others from being infected.

Keiki who wear masks indoors and get vaccinated enjoy significant protection against COVID-19.

SOURCE:
https://www.bmj.com/content/375/bmj-2021-068302 (BMJ)
https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/masking-science-sars-cov2.html (CDC)
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vaccinated.html (CDC)

Updated 12/16/2021