Johnson & Johnson released new data Tuesday showing a booster dose of its vaccine given two months after the one-shot vaccine provides 94% protection against moderate-to-severe COVID-19 symptoms. J&J, citing three studies of the vaccine, said the booster shot offers 100% protection against severe or critical symptoms, the company said in a statement. A booster dose given six months after the single shot provides even more protection, the company said. The results are in line with data from studies of Moderna and Pfizer-BioNTech vaccines. The one-dose J&J vaccine alone has been found to be 66% protective against moderate-to-severe disease overall worldwide, and 72% protective in the U.S.