Nation J&J, AstraZeneca may alter vaccines because of rare blood clots; FDA cites possible link between J&J, autoimmune disease: Live COVID news July 13, 2021 John Bacon, Elinor Aspegren and Steven Vargas, USA TODAY Comments Off on J&J, AstraZeneca may alter vaccines because of rare blood clots; FDA cites possible link between J&J, autoimmune disease: Live COVID news Johnson & Johnson and AstraZeneca conducting research into whether changes in their vaccines could eliminate rare blood clots. Latest COVID news.