Johnson & Johnson released data supporting the use of its COVID-19 vaccine as a booster shot for people previously vaccinated with its single-shot vaccine.   In anticipation of the potential need for boosters, the J&J conducted two Phase 1/2a studies in individuals previously vaccinated with its single-shot vaccine. New interim data from these studies demonstrate that a booster dose of the vaccine generated a rapid and robust increase in spike-binding antibodies, nine-fold higher than ...