Since commencement of COVID-19 pandemic, several SARS-CoV-2 variants have emerged amid containment efforts via vaccination. The Delta variant (B.1.617.2), discovered in October 2020, was designated as a VOC by the WHO on May 11, 2021. The enhanced transmissibility of Delta variant has been associated with critical mutations such as D614G, L452R, P681R, and T478K in the S-protein. The increased affinity of the S-protein and ACE2 has been postulated as a key reason for decreased vaccine efficacy. As per evidence, the Delta variant possesses increased transmissibility and decreased vaccine efficacy compared to other VOCs like Alpha and Beta. This has led to concerns regarding the acquisition of novel mutations in the Delta variant and outbreaks in vulnerable communities, including vaccinated people. In this mini-review of Delta variant, we have explained its evolution and characteristics, the impact of spike mutations on infectivity and immune evasion, and measures to combat future outbreaks.

The monkeypox disease is a zoonotic-infectious disease that transmits between animals and humans. It is caused by a double-stranded DNA virus belonging to the Orthopoxvirus genus that is closely related to the variola virus –the causative agent of smallpox. Although monkeypox infections were endemic to Western and Central Africa, the newly emerging monkeypox outbreak spread to more than 90 non-African countries. With the exception of the PCR-confirmed case of a return from Nigeria to the United Kingdom, the ongoing outbreak is largely unrelated to travel. In the most recent wave, cases are characteristically males in their thirties. Risk factors include close and particularly sexual contact with an infected person, and contact with fomites, infected animals or aerosolized-infectious material. Clinical diagnosis of monkeypox is confirmed with nucleic-acid amplification testing of samples originating from vesicles or genital lesions and using real-time or conventional PCR. Other methods, such as electron microscopy, immunohistochemistry, and virus culture are costly and time-consuming. In addition to timely diagnosis and contact tracing, restrictive measures to limit spread, such as isolation of infected patients, preventing contact with wild animals, and isolation of animals suspected to be viral reservoirs have shown promise. Although there are no specific treatments for monkeypox disease, the experience with smallpox suggests that the vaccinia vaccine, cidofovir, tecovirimat, and vaccinia immune globulin (IVG) may be beneficial for monkeypox treatment. In this review, we provide an update on the human-monkeypox disease with a special emphasis on its pathogenesis, prevention, diagnostics, and therapeutic measures.

As the therapeutic regimens against the COVID-19 remain scarce, the microRNAs (miRNAs) can be exploited to generate efficient therapeutic targets. The miRNAs have been found to play pivotal roles in the several regulatory functions influencing the prognosis of viral infection. The miRNAs have a prospective role in the up and down regulation of the ACE2 receptors. This review examines the clinical applications, as well as the possible threats associated with the use of miRNAs to combat the deleterious consequences of SARS-CoV-2 infection. This article was compiled to evaluate how the miRNAs are involved in the SARS-CoV-2 pathogenesis and infection, and their potential functions which could help in the development of therapeutic targets against the COVID-19. The sources of the collected information include the several journals, databases and scientific search engines such as the Google scholar, Pubmed, Science direct, official website of WHO, among the other sites. The investigations on the online platform were conducted using the keywords miRNA biogenesis, miRNA and ACE2 interaction, therapeutic role of miRNAs against SARS-CoV-2 and miRNA therapy side effects. This review has highlighted that the miRNAs can be exploited to generate potential therapeutic targets against the COVID-19. Changes in the miRNA levels following viral replication are an essential component of the host response to infection. The collection and modification of miRNA modulates may help to minimize the deleterious consequences of SARS-CoV-2 infection, such as by controlling or inhibiting the generation of cytokines and chemokines. The degradation of viral RNA by the cellular miRNAs, along with the reduced expression of ACE2 receptors, can substantially reduce the viral load. Specific miRNAs have been found to have an antiviral influence, allowing the immune system to combat the infection or forcing the virus into a latency stage. This review summarizes several studies revealing the involvement of miRNAs in diverse and complex processes during the infection process of SARS-CoV-2. The miRNAs can substantially reduce the viral load by degradation of viral RNA and reduced expression of ACE2 receptors, besides mitigating the deleterious consequences of the exaggerated secretion of cytokines. Extensive investigations need to be done by the scientific community to utilize the miRNA based strategies for the development of effective therapeutic targets against the COVID-19.