Omicron variant evolution on vaccines and monoclonal antibodies.

The severe acute respiratory syndrome coronavirus (SARS-CoV)-2 responsible for the global COVID-19 pandemic has caused almost 760 million confirmed cases and 7 million deaths worldwide, as of end-February 2023. Since the beginning of the first COVID-19 case, several virus variants have emerged: Alpha (B1.1.7), Beta (B135.1), Gamma (P.1), Delta (B.1.617.2) and then Omicron (B.1.1.529) and its sublineages. All variants have diversified in transmissibility, virulence, and pathogenicity. All the newly emerging SARS-CoV-2 variants appear to contain some similar mutations associated with greater "evasiveness" of the virus to immune defences. From early 2022 onward, several Omicron subvariants named BA.1, BA.2, BA.3, BA.4, and BA.5, with comparable mutation forms, have followed. After the wave of contagions caused by Omicron BA.5, a new Indian variant named Centaurus BA.2.75 and its new subvariant BA.2.75.2, a second-generation evolution of the Omicron variant BA.2, have recently been identified. From early evidence, it appears that this new variant has higher affinity for the cell entry receptor ACE-2, making it potentially able to spread very fast. According to the latest studies, the BA.2.75.2 variant may be able to evade more antibodies in the bloodstream generated by vaccination or previous infection, and it may be more resistant to antiviral and monoclonal antibody drug treatments. In this manuscript, the authors highlight and describe the latest evidences and critical issues have emerged on the new SARS-CoV-2 variants.

Antifungal Drug Resistance: An Emergent Health Threat.

Fungal infections, named mycosis, can cause severe invasive and systemic diseases that can even lead to death. In recent years, epidemiological data have recorded an increase in cases of severe fungal infections, caused mainly by a growing number of immunocompromised patients and the emergence of fungal pathogenic forms that are increasingly resistant to antimycotic drug treatments. Consequently, an increase in the incidence of mortality due to fungal infections has also been observed. Among the most drug-resistant fungal forms are those belonging to the Candida and Aspergillus spp. Some pathogens are widespread globally, while others are endemic in some areas only. In addition, some others may represent a health threat for some specific subpopulations and not for the general public. In contrast to the extensive therapeutic armamentarium available for the antimicrobial chemotherapeutic treatment of bacteria, for fungal infections there are only a few classes of antimycotic drugs on the market, such as polyenes, azoles, echinocandins, and a few molecules are under trial. In this review, we focused on the systemic mycosis, highlighted the antifungal drug compounds available in the pipeline, and analyzed the main molecular mechanisms for the development of antifungal resistance to give a comprehensive overview and increase awareness on this growing health threat.