Leveraging on the genomics and immunopathology of SARS-CoV-2 for vaccines development: prospects and challenges.

The incidence and case-fatality rates (CFRs) of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, the etiological agent for Coronavirus Disease 2019 (COVID-19), have been rising unabated. Even though the entire world has been implementing infection prevention and control measures, the pandemic continues to spread. It has been widely accepted that preventive vaccination strategies are the public health measures for countering this pandemic. This study critically reviews the latest scientific advancement in genomics, replication pattern, pathogenesis, and immunopathology of SARS-CoV-2 infection and how these concepts could be used in the development of vaccines. We also offer a detailed discussion on the anticipated potency, efficacy, safety, and pharmaco-economic issues that are and will be associated with candidate COVID-19 vaccines.

Evaluation of apoptotic protease-activating Factor-1 and cluster of Differentiation-4+ T-Cell counts in patients-infected with mycobacterium tuberculosis in Bauchi, Nigeria.

Background: This cross-sectional study evaluated Apoptotic Protease Activating Factor and cluster of differentiation-4+ (CD4+) T-cell counts in patients infected with Mycobacterium tuberculosis in Bauchi, Nigeria. Methods: This involved 180 blood samples from 90 tuberculosis (TB)-infected patients and 90 of their close contacts at home or attending Federal Medical Center Azare and Infectious Disease Hospital Bayara, Bauchi, Nigeria. The blood samples were analyzed for Apoptotic Protease Activating Factor (Apaf-1) expression using ELISA and CD4+ T cells using cyflow counter. Structured questionnaires were also used to collect the sociodemographic and clinical data of the study participants. Results: Eighty-six of the TB-infected patients had pulmonary TB (PTB), two had spine TB, and two had pleural TB. No statistically significant difference was recorded in CD4+ T-cell counts (P = 0.2935) between participants with PTB (mean ± standard deviation [SD]: 680.4 ± 235 cells/mm3) and those with extra-PTB (mean ± SD: 553.0 ± 130.5 cells/mm3). Similarly, there was no significant difference in Apaf-1 concentration (P = 0.1432) between participants with PTB (mean ± standard error of the mean [SEM]: 320.3 ± 35.4 pg/ml), and participants with extra-PTB (mean ± SEM: 143.7 ± 7.8 pg/ml). No significant difference was recorded in CD4+ T-cell counts (P = 0.4299) between the participants on treatment (mean ± SD: 758.6 ± 358.6 cells/mm3) and those who are treatment naïve (mean ± SD: 637.7 ± 208.4 cells/mm3). Similarly, there was no significant difference in Apaf-1 concentration (P = 0.6829) between the study participants on treatment (mean ± SEM: 336.3 ± 34.7 pg/ml) and those who are not on treatment (mean ± SEM: 381.2 ± 176.8 pg/ml). The CD4+ T-cells count was significantly higher in the controls (866.7 ± 288.4 cells/mm3) compared to the TB (675.0 ± 232.7 cells/mm3) patients (P < 0.0001). However, there was no significant difference in Apaf-1 expression between the control (312.4 ± 34.6 pg/ml) and the TB patients (329.1 ± 44.0 pg/ml) (P = 0.7658). Conclusion: Findings from this study showed a lower T-cell immune function during TB infection. However, Apaf-1 has no relevance on TB progression and control.

Clinical Significance of IgG Avidity Testing and Other Considerations in the Diagnosis of Congenital Cytomegalovirus Infection: A Review Update.

Prompt and accurate laboratory testing of women before or during antenatal days is necessary for detecting humoral immunological responses against cytomegalovirus (CMV) infection and assessing risk of congenital transmission. CMV is the most common viral etiology with the greatest propensity to induce neonatal pathologies. Most healthcare facilities in developing countries rely solely on anti-CMV IgM and IgG assays in diagnosing CMV infections. However, these parameters have some worrisome limitations. This study reviewed the significance of IgG avidity testing as a highly sensitive and specific tool that improves decisions regarding diagnosis of maternal and congenital CMV infections. We conducted this review from relevant published articles using an extensive literature search made through PubMed, Scopus and Google scholar on the concepts of congenital CMV (CCMV) transmission and clinical significance of IgG avidity testing in diagnosis of CCMV infections. Findings from our review revealed that IgG avidity testing in some developed societies was frequently utilized to resolve dilemmas associated with serodiagnosis of CMV infections, however, there is paucity of information in regards to its use in developing countries. The non-inclusion of IgG avidity testing during serological investigations of CMV could be a reason why congenital CMV infections and associated pathologies often go underdiagnosed in developing countries.

Absence of poliovirus in apparently healthy school children in Bauchi state, Nigeria.

INTRODUCTION: Poliovirus infections have been established to be in circulation in the remaining three polio-endemic nations. These pathogens have been associated with several chronic diseases, particularly acute flaccid paralysis of children. This study sought to ascertain whether polioviruses are silently shed by apparently healthy schoolchildren in Bauchi, Katagum, and Misau local government areas of Bauchi state, Nigeria. METHODOLOGY: This was a cross-sectional prospective study that involved 200 stool samples collected from apparently healthy schoolchildren. All samples were processed and inoculated onto rhabdomyosarcoma (RD) and L20B cell-lines. Inoculated cell lines were monitored for cytopathic effects (CPEs) for 10 days with one subculture after first 5 days. RESULTS: None of the samples came down with CPEs on L20B, and thus all samples were negative for poliovirus; however, three were positive for non-polio enteroviruses (NPEVs) on RD and not on the L20B cell line: one coxsackie B virus from a seven-year-old male, and two others were untypeable isolates, one each from a male and a female child. The coxsackie B virus was identified by microneutralization test using polyclonal sera as described by the World Health Organization. CONCLUSIONS: Findings from this investigation indicate the absence of polioviruses in the children studied. This is an indication of good polio immunization coverage in these communities. However, more intensive and periodic surveillance is required to confirm the presence or exclude the absence of polioviruses in these communities and other parts of Nigeria.

Molecular Detection and Clinical Implications of HTLV-1 Infections among Antiretroviral Therapy-Naïve HIV-1-Infected Individuals in Abuja, Nigeria.

BACKGROUND: Individuals with human T-cell lymphotrophic virus type-1 (HTLV-1)/HIV-1 coinfection have been demonstrated to undergo CD4+ lymphocytosis even in the face of immunodeficiency and increased vulnerability to opportunistic pathogens that can lead to poor prognosis. OBJECTIVE: This study investigated the prevalence as well as the effects of HIV-1/HTLV-1 coinfection on CD4+ cell counts, routine hematology, and biochemical parameters of study participants. MATERIALS AND METHODS: This prospective cross-sectional study involved 184 blood samples collected from HIV-1-seropositive individuals attending HIV-special clinic of the University of Abuja Teaching Hospital, Gwagwalada, Nigeria. These samples were analyzed for anti-HTLV-1/2 IgM antibodies using enzyme-linked immunosorbent assay, CD4+ cell counts, and some routine hematological and biochemical parameters. All samples were also tested for HTLV-1 provirus DNA using real-time polymerase chain reaction (PCR) assay. RESULTS: Of the 184 subjects studied, 9 (4.9%) were anti-HTLV-1/2 IgM seropositive; however, upon real-time PCR testing, 12 (6.5%) had detectable HTLV-1 provirus DNA. The CD4+ cell count was significantly high in HTLV-1-positive (742 ± 40.2) subjects compared to their HTLV-1-negative (380 ± 28.5) counterpart (P-value = 0.025). However, there was no significant association between HTLV-1 positivity with other hematology and biochemical parameters studied (P > 0.05). CONCLUSION: All subjects (100%) who were HTLV-1/HIV-1-coinfected had normal CD4+ counts. This gives contrasting finding on the true extent of immunodeficiency of subjects. So it is suggested to be very careful in using only CD4+ counts to monitor disease progression and as indicators for antiretroviral therapy (ART) in resource-limited settings. In such conditions, there may be a need to test for HTLV-1 alongside HIV viral loads in order to begin appropriate ART regimens that contain both pathogens.