Use of Johnson and Johnson’s (J&J) COVID-19 vaccine should only be limited to certain adults, the FDA said on Thursday. Due to an updated analysis of the rare cases of thrombosis with thrombocytopenia syndrome (TTS), which typically occur 1 to 2 weeks after vaccination, use of the J&J vaccine should be restricted to those for whom mRNA vaccines are “not accessible or clinically appropriate,” or who would not get vaccinated if not for the J&J vaccine, the agency said. Read more.