Therapeutic Options for Coronavirus Disease 2019 (COVID-19): Where Are We Now?

Aptamer-Based Strategies to Address Challenges in COVID-19 Diagnosis and Treatments

Coronavirus disease (COVID-19), a highly contagious and rapidly spreading disease with significant fatality in the elderly population, has swept across the world since 2019. Since its first appearance, the causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has undergone multiple mutations, with Omicron as the predominant circulating variant of concern at the moment. The gold standard for diagnosis of COVID-19 by real-time polymerase chain reaction (RT-PCR) to detect the virus is laborious and requires well-trained personnel to perform sophisticated procedures. Also, the genetic variants of SARS-CoV-2 that arise regularly could result in false-negative detection. Meanwhile, the current COVID-19 treatments such as conventional medicine, complementary and alternative medicine, passive antibody therapy, and respiratory therapy are associated with adverse effects. Thus, there is an urgent need to discover novel diagnostic and therapeutic approaches against SARS-CoV-2 and its variants. Over the past 30 years, nucleic acid-based aptamers have gained increasing attention and serve as a promising alternative to the antibodies in the diagnostic and therapeutic fields with their uniqueness of being small, nonimmunogenicity, and thermally stable. Aptamer targeting the SARS-CoV-2 structural proteins or the host receptor proteins represent a powerful tool to control COVID-19 infection. In this review, challenges faced by currently available diagnostic and therapeutic tools for COVID-19 are underscored, along with how aptamers can shed a light on the current COVID-19 pandemic, focusing on the critical factors affecting the discovery of high-affinity aptamers and their potential applications to control COVID-19 infection.

Sensitivity to Vaccines, Therapeutic Antibodies, and Viral Entry Inhibitors and Advances To Counter the SARS-CoV-2 Omicron Variant

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) keeps evolving and mutating into newer variants over time, which gain higher transmissibility, disease severity, and spread in communities at a faster rate, resulting in multiple waves of surge in Coronavirus Disease 2019 (COVID-19) cases. A highly mutated and transmissible SARS-CoV-2 Omicron variant has recently emerged, driving the extremely high peak of infections in almost all continents at an unprecedented speed and scale. The Omicron variant evades the protection rendered by vaccine-induced antibodies and natural infection, as well as overpowers the antibody-based immunotherapies, raising the concerns of current effectiveness of available vaccines and monoclonal antibody-based therapies. This review outlines the most recent advancements in studying the virology and biology of the Omicron variant, highlighting its increased resistance to current antibody-based therapeutics and its immune escape against vaccines. However, the Omicron variant is highly sensitive to viral fusion inhibitors targeting the HR1 motif in the spike protein, enzyme inhibitors, involving the endosomal fusion pathway, and ACE2-based entry inhibitors. Omicron variant-associated infectivity and entry mechanisms of Omicron variant are essentially distinct from previous characterized variants. Innate sensing and immune evasion of SARS-CoV-2 and T cell immunity to the virus provide new perspectives of vaccine and drug development. These findings are important for understanding SARS-CoV-2 viral biology and advances in developing vaccines, antibody-based therapies, and more effective strategies to mitigate the transmission of the Omicron variant or the next SARS-CoV-2 variant of concern.

Bayesian Modeling of COVID-19 to Classify the Infection and Death Rates in a Specific Duration: The Case of Algerian Provinces

COVID-19 causes acute respiratory illness in humans. The direct consequence of the spread of the virus is the need to find appropriate and effective solutions to reduce its spread. Similar to other countries, the pandemic has spread in Algeria, with noticeable variation in mortality and infection rates between regions. We aimed to estimate the proportion of people who died or became infected with SARS-CoV-2 in each provinces using a Bayesian approach. The estimation parameters were determined using a binomial distribution along with an a priori distribution, and the results had a high degree of accuracy. The Bayesian model was applied during the third wave (1 January-15 August 2021), in all Algerian's provinces. For spatial analysis of duration, geographical maps were used. Our findings show that Tissemsilt, Ain Defla, Illizi, El Taref, and Ghardaia (Mean = 0.001) are the least affected provinces in terms of COVID-19 mortality. The results also indicate that Tizi Ouzou (Mean = 0.0694), Boumerdes (Mean = 0.0520), Annaba (Mean = 0.0483), Tipaza (Mean = 0.0524), and Tebessa (Mean = 0.0264) are more susceptible to infection, as they were ranked in terms of the level of corona infections among the 48 provinces of the country. Their susceptibility seems mainly due to the population density in these provinces. Additionally, it was observed that northeast Algeria, where the population is concentrated, has the highest infection rate. Factors affecting mortality due to COVID-19 do not necessarily depend on the spread of the pandemic. The proposed Bayesian model resulted in being useful for monitoring the pandemic to estimate and compare the risks between provinces. This statistical inference can provide a reasonable basis for describing future pandemics in other world geographical areas.

Omicron (B.1.1.529) variant of SARS-CoV-2: Concerns, challenges, and recent updates

Omicron has shown immune escape from neutralizing antibodies generated through previous infection or vaccination. It could evade the protection provided by mAbs being used in clinics for treating coronavirus disease 2019 (COVID‐19) patients. Booster dose is recommended to elevate the protective levels of antibodies in COVID‐19 vaccinated individuals. The development of powerful oral antiviral drugs such as Molnupiravir and Paxlovid have shown promising clinical results and raised new hopes of COVID‐19 treatment. High efforts are being made to develop highly efficacious vaccines, and by implementing appropriate prevention and control strategies to counter Omicron.