Thanks to current medical advances, many diseases are preventable or curable; however, the emergence of an epidemic or pandemic without definitive treatment poses a major challenge for the medical community and the general population. Severe acute respiratory syndrome coronavirus ۲ (SARS-CoV-۲) an emerging disease, common between humans and animals, appeared in ۲۰۱۹ and led to COVID-۱۹ (۱). Coronaviruses are the cause of ۱۵% of respiratory diseases and can be transmitted from animal to human or vice versa. COVID-۱۹ has high transmissibility; also its latency period is long (۲). COVID-۱۹ can infect individuals through means such as respiratory droplets and contact with secretions containing the virus. COVID-۱۹ is considered a multi-organic disease. Coronaviruses are a family of RNA and other Nidovirales. Acquired Immunodeficiency Syndrome (AIDS) is a member of the Lentivirus family of animal retroviruses, which can cause long-term latent infection in cells and short-term cytotoxic effects leading to progressive and fatal diseases. Each humanimmunodeficiency virus (HIV) consists of two identical single-stranded RNA molecules encoded in viral proteins. The virus has the same basic nucleic acid sequence as all known retroviruses (۳). The hepatitis C virus also infects people through similar routes of HIV transmission, with an emphasis on blood transfusions. It is a member of the Flaviviridae and Hepacivirus (۴). So far, no approved vaccine has been developed for hepatitis C and HIV (۵). Currently, more than ۱۲۰ million people have been infected and ۲.۵ million deaths due to COVID-۱۹ have been reported worldwide; while, the number of people living with HIV and hepatitis C are ۳۸ million and ۷۱ million, respectively; all being RNA virus-induced diseases. So far, no vaccine for hepatitis C and HIV has been approved, while in November ۲۰۲۰ Pfizer and Moderna (۶, ۷) announced positive results from the analysis of their phase III pilot trials about their vaccine against acute respiratory syndrome virus (SARS-COV-۲).
