Clinical Characteristics and Treatment of Anosmia and Ageusia Due to SARS-CoV2 Variants

The SARS-CoV-2 pandemic has consisted of multiple surges of infection because of continuous viral mutations. The WHO and CDC have defined the main SARS-CoV-2 variants based on international and national data for the circulation of SARS-CoV-2 into at least 4 waves. Studies from different parts of the world have demonstrated significant variations in the clinical manifestations of viral infection in relation to different SARS-CoV-2 variants. They also indicated that the current high levels of population immunity, due to prior infection and/or vaccination, have been associated with a vastly decreased overall risk of severe disease. Anosmia (with or without ageusia) was identified as a hallmark of COVID-19 early in the pandemic (ancestral Wuhan strain, alpha and delta variants), with a prevalence of \~60%. Prolonged olfactory disorders, lasting ≥6 months to years, has been reported in \~35-40% of infected individuals. However, studies reported that olfactory and gustatory disorders were less frequent with Omicron variants compared to pre-omicron variants. It has been indicated that SARS-CoV-2 can cause destruction, disorganization and molecular changes in the nasal olfactory neuroepithelium resulting in loss and distortion of the sense of smell. There are several trials to treat these persistent disorders but none has shown significant positive results except ours (Hamed et al., Expert Review of Clinical Pharmacology 2023;16(12):1261-1276 DOI: 10.1080/17512433.2023.2282715). Hamed et al. reported that cerebrolycin, a commercially available multimodal neurotropic factor, has the ability to cure at least 60% (100% complete and persistent recovery) of post-covid-19 persistent olfactory and gustatory dysfunctions. This drug is available in the market of at least 75 countries since 1996 and easily dispensed from local pharmacies after doctors prescriptions. It is used for treatment of many disorders of the central and peripheral nervous systems. This could be due to its abil