This is about an earlier strain of coronavirus.
Source:
- April 20, 2012. Chien-Te Tseng, Elena Sbrana, Naoko Iwata-Yoshikawa, Patrick C. Newman, Tania Garron, Robert L. Atmar, Clarence J. Peters, and Robert B. Couch. “Immunization with SARS Coronavirus Vaccines Leads to Pulmonary Immunopathology on Challenge with the SARS Virus.” PLOS ONE 7 (4): e35421.
https://doi.org/10.1371/journal.pone.0035421.
Research Journal.