(Mary Altaffer | AP) The Johnson & Johnson COVID-19 vaccine sits on a table in the Staten Island borough of New York, Thursday, April 8, 2021. The vaccine is produced by Janssen Pharmaceutical Companies, a subsidiary of Johnson & Johnson. University of Utah Health recently treated a man for blood clots he may have developed as a reaction to his immunization with the Johnson & Johnson vaccine, the health system announced Wednesday, May 5, 2021.