Johnson & Johnson COVID-19 vaccine – Wikipedia

The Johnson & Johnson COVID-19 vaccine is a human adenovirus viral vector COVID-19 vaccine developed by Janssen Vaccines, Belgian subsidiary of American company Johnson & Johnson (J&J); and Beth Israel Deaconess Medical Center (BIDMC), based in Boston, Massachusetts. On 29 January 2021, Janssen announced that it was 66% effective in a one-dose regimen in preventing symptomatic COVID-19, with …

https://en.wikipedia.org/wiki/Ad26.COV2.S