HIV and AIDS in relation to other pandemics. Among the viruses plaguing humans, HIV is a recent acquisition. Its outstanding success as an infection poses immense scientific challenges to human health and raises the question "What comes nest?"

Case fatality rates of COVID-19 across the globe: are the current draconian measures justified?

Aim

The current study assessed the case fatality rate (CFR) across different income level countries of the world, and the virulence pattern of COVID-19, against the backdrop of panic and uncertainty faced by many governments, who are trying to impose draconian containment measures to control the outbreak. Subjects and Methods: Data on confirmed cases and number of deaths due to coronavirus infection were retrieved from the WHO as on 30 March 2020, and examined for the various income level countries, per the World Bank criteria. The CFR was calculated country-wise and estimated for the various groups such as low, lower-middle, upper-middle, and high-income, and the data was analyzed.

Results

The overall CFR for the high income countries was 5.0%, compared with a CFR of 2.8% for low-income countries. The upper-middle-income countries showed a CFR of 4.3%, while the lower-middle-income countries stood at 3.7%. The results from our study predict that the maximum CFR in high-income countries will be contained at approximately 5% (95% CI). The CFR for the low, lower-middle, and upper-middle-income countries will range between 2.8 and 4.3% (95% CI).

Conclusion

COVID-19, irrespective of its transmissibility, produces a lower CFR compared with that of SARS-Cov and MERS-Cov, although COVID-19 has infected eight times more countries than MERS-Cov and SARS-Cov, and caused a higher number of deaths. The nation-wide lockdown measures to prevent the spread of the virus may be reconsidered, given the hardships for the population and their impact on the economic system.

The Hard Way towards an Antibody-Based HIV-1 Env Vaccine: Lessons from Other Viruses

Although effective antibody-based vaccines have been developed against multiple viruses, such approaches have so far failed for the human immunodeficiency virus type 1 (HIV-1). Despite the success of anti-retroviral therapy (ART) that has turned HIV-1 infection into a chronic disease and has reduced the number of new infections worldwide, a vaccine against HIV-1 is still urgently needed. We discuss here the major reasons for the failure of “classical” vaccine approaches, which are mostly due to the biological properties of the virus itself. HIV-1 has developed multiple mechanisms of immune escape, which also account for vaccine failure. So far, no vaccine candidate has been able to induce broadly neutralizing antibodies (bnAbs) against primary patient viruses from different clades. However, such antibodies were identified in a subset of patients during chronic infection and were shown to protect from infection in animal models and to reduce viremia in first clinical trials. Their detailed characterization has guided structure-based reverse vaccinology approaches to design better HIV-1 envelope (Env) immunogens. Furthermore, conserved Env epitopes have been identified, which are promising candidates in view of clinical applications. Together with new vector-based technologies, considerable progress has been achieved in recent years towards the development of an effective antibody-based HIV-1 vaccine.

Effects of immunosuppressive drugs on HIV infection: implications for solid-organ transplantation

With the advent of highly active antiretroviral therapy (HAART), HIV infection has become a chronic disease. Various end-stage organ failures have now become common co-morbidities and are primary causes of mortality in HIV-infected patients. Solid-organ transplantation therefore has been proposed to these patients, as HIV infection is not anymore considered an absolute contraindication. The initial results of organ transplantation in HIV-infected patients are encouraging with no differences in patient and graft survival compared with non-HIV-infected patients. The use of immunosuppressive drug therapy in HIV-infected patients has so far not shown major detrimental effects, and some drugs in combination with HAART have even demonstrated possible beneficial effects for specific HIV settings. Nevertheless, organ transplantation in HIV-infected patients remains a complex intervention, and more studies will be required to clarify open questions such as long-term effects of drug interactions between antiretroviral and immunosuppressive drugs, outcome of recurrent HCV infection in HIV-infected patients, incidence of graft rejection, or long-term graft and patient survival. In this article, we first review the immunological pathogenesis of HIV infection and the rationale for using immunosuppression combined with HAART. We then discuss the most recent results of solid-organ transplantation in HIV-infected patients.

Dihydroxythiophenes are novel potent inhibitors of human immunodeficiency virus integrase with a diketo acid-like pharmacophore

We have identified dihydroxythiophenes (DHT) as a novel series of human immunodeficiency virus type 1 (HIV-1) integrase inhibitors with broad antiviral activities against different HIV isolates in vitro. DHT were discovered in a biochemical integrase high-throughput screen searching for inhibitors of the strand transfer reaction of HIV-1 integrase. DHT are selective inhibitors of integrase that do not interfere with virus entry, as shown by the inhibition of a vesicular stomatitis virus G-pseudotyped retroviral system. Moreover, in quantitative real-time PCR experiments, no effect on the synthesis of viral cDNA could be detected but rather an increase in the accumulation of 2-long-terminal-repeat cycles was detected. This suggests that the integration of viral cDNA is blocked. Molecular modeling and the structure activity relationship of DHT demonstrate that our compound fits into a two-metal-binding motif that has been suggested as the essential pharmacophore for diketo acid (DKA)-like strand transfer inhibitors (Grobler et al., Proc. Natl. Acad. Sci. USA 99:6661-6666, 2002.). This notion is supported by the profiling of DHT on retroviral vectors carrying published resistance mutations for DKA-like inhibitors where DHT showed partial cross-resistance. This suggests that DHT bind to a common site in the catalytic center of integrase, albeit with an altered binding mode. Taken together, our findings indicate that DHT are novel selective strand transfer inhibitors of integrase with a pharmacophore homologous to DKA-like inhibitors.

Coassembly and complementation of Gag proteins from HIV-1 and HIV-2, two distinct human pathogens

Approximately one million people in the world are dually infected with both HIV-1 and HIV-2. To identify potential interactions between these two human pathogens, we examined whether HIV-1 and HIV-2 Gag proteins can coassemble and functionally complement each other. We generated HIV-1- and HIV-2-based vectors with mutations in Gag; compared with wild-type vectors, these mutants had drastically decreased viral titers. Coexpression of the mutant HIV-1 and HIV-2 Gag could generate infectious viruses; furthermore, heterologous complementation in certain combinations showed efficiency similar to homologous complementation. Additionally, we used bimolecular fluorescence complementation analysis to directly demonstrate that HIV-1 and HIV-2 Gag can interact and coassemble. Taken together, our results indicate that HIV-1 and HIV-2 Gag polyproteins can coassemble and functionally complement each other during virus replication; to our knowledge, this is the first demonstration of its kind. These studies have important implications for AIDS treatment and the evolution of primate lentiviruses.

Gene therapy progress and prospects: novel gene therapy approaches for AIDS

Acquired immunodeficiency syndrome (AIDS), caused by human immunodeficiency virus (HIV), kills millions worldwide every year. Vaccines against HIV still seem a distant promise. Pharmaceutical treatments exist, but these are not always effective, and there is increasing prevalence of viral strains with multidrug resistance. Highly active antiretroviral therapy (HAART) consists of inhibitors of viral enzymes (reverse transcriptase (RT) and protease). Gene therapy, first introduced as intracellular immunization, may offer hopes for new treatments to be used alone, or in conjunction with, conventional small molecule drugs. Gene therapy approaches against HIV-1, including suicide genes, RNA-based technology, dominant negative viral proteins, intracellular antibodies, intrakines, and peptides, are the subject of this review.

HIV and AIDS: looking ahead

Although the future of HIV science is uncertain, we need to reappraise HIV diversity, pathogenesis and immunity. The AIDS pandemic threatens the success of existing vaccine programs and may accelerate the emergence of new infectious diseases.