Previous coronavirus vaccine efforts — for severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and respiratory syncytial virus (RSV) — have revealed a serious concern: The vaccines have a tendency to trigger antibody-dependent enhancement.

Peeples, L. News Feature: Avoiding Pitfalls in the Pursuit of a COVID-19 Vaccine. Proceedings of the National Academy of Sciences, vol. 117, no. 15. 14 April 2020. https://doi:10.1073/pnas.2005456117.