In July 2021, Janssen hired Heaton away from the Gates Foundation, where she’d been director of vaccine development for eight years, and CEO of the Gates Medical Research Institute since its 2018 launch. That landed her in a debate over the efficacy of the “one-dose” adenovirus vaccine developed by Janssen, a division of Johnson & Johnson. A second dose, she argued, would raise the vaccine’s efficacy into the same range as that of the Moderna and Pfizer mRNA vaccines. In October the FDA agreed, urging all J&J recipients to get a booster. Heaton says J&J’s experience with the adenovirus platform will speed development of vaccines for other diseases, such as Ebola and respiratory syncytial virus.