MANY countries and labs are currently looking for a COVID-19 vaccine but have yet to explore it. Many species of Spirulina contain significant active compounds such as sulfated polysaccharides, phenols, phycobiliproteins, and calcium spirulan with inhibition activity against replication of viruses, especially influenza A (H1N1), HCV , and HIV viral infection. As there is no vaccine was approved against COVID-19, the potential of using Spirulina as antivirus and an immune agent has been tested for many viruses, and this encourages using the Spirulina as a whole amount or its extract for immunization against COVID-19, the causative pathogen of Coronavirus disease. The present article discusses some of the important studies on the therapeutic antiviral activities of the cyanobacterium Spirulina platensis.