Comparative Pharmacological Efficacy of COVID-19 Vaccines against the Variants of Concerns (VOCs) of SARS-CoV-2: Recent Clinical Studies on Booster Dose.

Sera obtained from convalescent individuals, and vaccinated individuals can induce low neutralizing efficacy against variants of concerns (VOCs) of SARS-CoV-2. In addition, the majority of COVID-19 vaccines are less efficacious against VOCs when compared to their efficacy against the original virus. Immune escape is one of the significant mechanisms observed during SARS-CoV-2 infection due to the substantial mutational capacity of VOCs such as B.1.1.7, P.1, B.1.351, B.1.617.2, C.37, and B.1.621. Omicron, a novel strain of SARS-CoV-2, also referred to as B.1.1.529, was identified in South Africa. This variant is a potential new VOC by the World Health Organization (WHO), and confirmed cases have been arising across several nations due to its rapid spreading ability. Omicron variant can acquire substantial immune escape following Delta, Beta/Gamma D614G VOCs and subsequently facilitating potential infectivity due to its enhanced ACE2 binding ability. The Omicron variant is a highly mutated variant accompanied by higher transmissibility and immune evasion. This mini review describes the ability of VOCs to acquire immune escape and also describes the comparative neutralization efficacy of several vaccines, including Booster doses against SARS-CoV-2.

Antibody Responses and CNS Pathophysiology of Mucormycosis in Chronic SARS Cov-2 Infection: Current Therapies Against Mucormycosis.

The incidence rate of opportunistic secondary infections through invasive fungi has been observed to be 14.5% to 27% in the SARS CoV pandemic during the year 2003. However, the incidence of SARS CoV-2 is accompanied by a substantial rise in secondary opportunistic infections like mucormycosis (black fungus), mainly in the immunocompromised individuals and diabetic patients taking steroids. Substantial rates of COVID-19 cases with mucormycosis were reported in India and other parts of the world. Previous research reports delineated the ability of Mucorales to invade the various tissues like lungs, brain, and sinus through the GRP78, and subsequently, this infection could invoke crusting, edema, and necrosis of the brain parenchyma, ptosis, proptosis, and vision loss due to intraorbital and intracranial complications. Similarities of these pathophysiological complications with already existing diseases are causing clinicians to face several challenges in order to diagnose and treat this disease effectively at the early stage. This minireview depicts the mucormycosis-induced immune and pathophysiological alterations in COVID-19 patients comorbid with diabetes and immunosuppression and also reported the various clinical manifestations, the therapeutic modalities, and the failures of anti-fungal vaccines. Therefore, the emerging mucormycosis in COVID-19 patients needs rapid investigation and selective optimization of the effective therapeutic modalities, including antifungal vaccines, to minimize the mortality rate.

Development of antibody resistance in emerging mutant strains of SARS CoV-2: Impediment for COVID-19 vaccines.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a highly infectious agent associated with unprecedented morbidity and mortality. A failure to stop growth of COVID-19-linked morbidity rates is caused by SARS-CoV-2 mutations and the emergence of new highly virulent SARS-CoV-2 strains. Several acquired SARS-CoV-2 mutations reflect viral adaptations to host immune defence. Mutations in the virus Spike-protein were associated with the lowered effectiveness of current preventive therapies, including vaccines. Recent in vitro studies detected diminished neutralisation capacity of vaccine-induced antibodies, which are targeted to bind Spike receptor-binding and N-terminal domains in the emerging strains. Lower than expected inhibitory activity of antibodies was reported against viruses with E484K Spike mutation, including B.1.1.7 (UK), P.1 (Brazil), B.1.351 (South African), and new Omicron variant (B.1.1.529) with E484A mutation. The vaccine effectiveness is yet to be examined against new mutant strains of SARS-CoV-2 originating in Europe, Nigeria, Brazil, South Africa, and India. To prevent the loss of anti-viral protection in vivo, often defined as antibody resistance, it is required to target highly conserved viral sequences (including Spike protein) and enhance the potency of antibody cocktails. In this review, we assess the reported mutation-acquiring potential of coronaviruses and compare efficacies of current COVID-19 vaccines against 'parent' and 'mutant' strains of SARS-CoV-2 (Kappa (B.1.617.1), Delta (B.1.617.2), and Omicron (B.1.1.529)).