The SARS-CoV-2 coronavirus epidemic is hastening the discovery of the most efficient vaccines. The development of cost-effective vaccines seems to be the only solution to terminate this pandemic. However, the vaccines’ effectiveness has been questioned due to recurrent mutations in the SARS-CoV-2 genome. Most of the mutations are associated with the spike protein, a vital target for several marketed vaccines. Many countries were highly affected by the 2nd wave of the SARS-CoV-2, like the UK, India, Brazil and France. Experts are also alarming the further COVID-19 wave with the emergence of Omicron, which is highly affecting the South African populations. This review encompasses the detailed description of all vaccine candidates and COVID-19 mutants that will add value to design further studies to combat the COVID-19 pandemic. The information was generated using various search engines like google scholar, PubMed, clinicaltrial.gov.in, WHO database, ScienceDirect, and news portals by using keywords SARS-CoV-2 mutants, COVID-19 vaccines, efficacy of SARS-CoV-2 vaccines, COVID-19 waves. This review has highlighted the evolution of SARS-CoV-2 variants and the vaccine efficacy. Currently, various vaccine candidates are undergoing several phases of development. Their efficacy still needs to check for newly emerged variants. We have focused on the evolution, multiple mutants, waves of the SARS-CoV-2, and different marketed vaccines undergoing various clinical trials and the design of the trials to determine vaccine efficacy. Various mutants of SARS-CoV-2 arrived, mainly concerned with the spike protein, a key component to design the vaccine candidates. Various vaccines are undergoing clinical trial and show impressive results, but their efficacy still needs to be checked in different SARS-CoV-2 mutants. We discussed all mutants of SARS-CoV-2 and the vaccine’s efficacy against them. The safety concern of these vaccines is also discussed. It is important to understand how coronavirus gets mutated to design better new vaccines, providing long-term protection and neutralizing broad mutant variants. A proper study approach also needs to be considered while designing the vaccine efficacy trials, which further improved the study outcomes. Taking preventive measures to protect from the virus is also equally important, like vaccine development.

Over the past decade, the gut microbiota has emerged as an important frontier in understanding the human body's homeostasis and the development of diseases. Gut flora in human beings regulates various metabolic functionalities, including enzymes, amino acid synthesis, bio-transformation of bile acid, fermentation of non-digestible carbohydrates (NDCs), generation of indoles and polyamines (PAs), and production of short-chain fatty acids (SCFAs). Among all the metabolites produced by gut microbiota, SCFAs, the final product of fermentation of dietary fibers by gut microbiota, receive lots of attention from scientists due to their pharmacological and physiological characteristics. However, the molecular mechanisms underlying the role of SCFAs in the interaction between diet, gut microbiota, and host energy metabolism is still needed in-depth research. This review highlights the recent biotechnological advances in applying SCFAs as important metabolites to treat various diseases and maintain colonic health.

Breast cancer (BC) is mostly observed in women and is responsible for huge mortality in women subjects globally. Due to the continued development of drug resistance and other contributing factors, the scientific community needs to look for new alternatives, and drug repurposing is one of the best opportunities. Here we light upon the drug repurposing with a major focus on breast cancer. BC is a division of cancer known as the leading cause of death of 2.3 million women globally, with 685,000 fatalities. This number is steadily rising, necessitating the development of a treatment that can extend survival time. All available treatments for BC are very costly as well as show side effects. This unfulfilled requirement of the anti-cancer drugs ignited an enthusiasm for drug repositioning, which means finding out the anti-cancer use of already marketed drugs for other complications. With the advancement in proteomics, genomics, and computational approaches, the drug repurposing process hastens. So many drugs are repurposed for the BC, including alkylating agents, antimetabolite, anthracyclines, an aromatase inhibitor, mTOR, and many more. The drug resistance in breast cancer is rising, so reviewing how the challenges in breast cancer can be combated with drug repurposing. This paper provides the updated information on all the repurposed drugs candidates for breast cancer with the molecular mechanism responsible for their anti-tumor activity. Additionally, all the challenges that occur during the repurposing of the drugs are discussed.

Many biological activities of pyridine and thiazole derivatives have been reported, including antiviral activity and, more recently, as COVID-19 inhibitors. Thus, in this paper, we designed, synthesized, and characterized a novel series of N-aminothiazole-hydrazineethyl-pyridines, beginning with a N′-(1-(pyridine-3-yl)ethylidene)hydrazinecarbothiohydrazide derivative and various hydrazonoyl chlorides and phenacyl bromides. Their Schiff bases were prepared from the condensation of N-aminothiazole derivatives with 4-methoxybenzaldehyde. FTIR, MS, NMR, and elemental studies were used to identify new products. The binding energy for non-bonding interactions between the ligand (studied compounds) and receptor was determined using molecular docking against the SARS-CoV-2 main protease (PDB code: 6LU7). Finally, the best docked pose with highest binding energy (8a = −8.6 kcal/mol) was selected for further molecular dynamics (MD) simulation studies to verify the outcomes and comprehend the thermodynamic properties of the binding. Through additional in vitro and in vivo research on the newly synthesized chemicals, it is envisaged that the achieved results will represent a significant advancement in the fight against COVID-19.

• SARS-CoV-2 can also affect organs other than the lungs, including the brain, heart, and gastrointestinal system. • Patients with Cancer, HIV, COPD, neurological, and CVDs are more prone to the COVID-19 associated complications, leading to a drastic rise in morbidity and mortality. • Elderly and pre-existing polypharmacy patients have worsened COVID-19 associated complications. When a person with comorbidity is infected with SARS-CoV-2, it becomes more dangerous, and managing these patients with adequate medical care is critical to their survival. • A co-morbid person should adhere to preventive measures to reduce mortality, including regular handwashing with soap or using an alcohol-based hand sanitizer, minimizing in person contact and practicing social distance, wearing a face mask in public places, and avoiding going to public places unless essential are among the precautional measures.