Abstract
2.5 × 1010 vp Ad26.COV2.S elicited robust SARS-CoV-2-specific antibody responses in adolescents through 6 months, with acceptable safety and reactogenicity profiles. Compared with adults immunized with 5 × 1010 vp Ad26.COV2.S, adolescents had higher antibody levels, despite being vaccinated with a lower dose.