From that article: It's not a big deal to begin with and researchers have seen no problems: "No definitive role for ADE in human coronavirus diseases has been established." Effective vaccines will not be a significant risk: "These data suggest that human immunization strategies for SARS-CoV-2 that elicit high neutralizing antibody titres have a high chance of success with minimal risk of ADE." Inactivated virus vaccines (which we do not use) might be a problem: "Vaccines with a high theoretical risk of inducing pathologic ADE or ERD include inactivated viral vaccines . . ." How will we know if the vaccines are safe? "Should it occur, ERD caused by human vaccines will first be observed in larger phase II and/or phase III efficacy trials that have sufficient infection events for statistical comparisons between the immunized and placebo control study arms." We did those larger phase II and phase III trials and it was not observed. (This paper was published 10 months ago, before the vaccine trials were completed.) So it turns out it's not a problem. Good news, eh?