On Oct. 20, 2021, Johnson & Johnson announced the U.S. Food and Drug Administration (FDA) had issued
Emergency Use Authorization (EUA) for a booster dose of the Johnson & Johnson COVID-19 vaccine for adults aged 18 and older at least two months following primary vaccination with single-shot Johnson & Johnson COVID-19 vaccine; and for eligible individuals who received a different authorized or approved COVID-19 vaccine.

The Johnson & Johnson booster shot was the same formulation and dosage as the primary shot.