Janssen COVID-19 vaccine - Wikipedia
en.wikipedia.org › wiki › Janssen_COVID-19_vaccinee. The Janssen COVID-19 vaccine, or Johnson & Johnson COVID-19 vaccine, is a COVID-19 vaccine that was developed by Janssen Vaccines in Leiden, Netherlands, and its Belgian parent company Janssen Pharmaceuticals, a subsidiary of American company Johnson & Johnson. It is a viral vector vaccine based on a human adenovirus that has been modified ...