As medical science and technology advance rapidly, better COVID-19 vaccines for SARS-CoV-2 variants, effective antiviral or antimicrobial drugs, innovative immunotherapies (such as monoclonal antibodies for prion-like alpha-synuclein proteins and therapeutic vaccines for PD or parkinsonism), as well as new (or unconventional) therapies will be developed and made available in the near future, which will help prevent a possible epidemic or global spreading of post-COVID-19 parkinsonism in the 21st century. This evidence concerns the gene SNCA and Parkinson disease.