Publications by authors named "Isaac Ngare"
COVID-19 vaccine became available in Tanzania during the first wave of the Omicron variant. During that time community seroprevalence of SARS-CoV-2 was already at 50%-80%. To date, it remains largely unknown whether ongoing vaccination with the primary series vaccines has any meaningful immune-boosting effects against newer Omicron subvariants.
View Article and Find Full Text PDFPeople living with HIV (PLWH) could be at risk of blunted immune responses to COVID-19 vaccination. We investigated factors associated with neutralizing antibody (NAb) responses against SARS-CoV-2 and variants of concern (VOCs), following two-dose and third booster monovalent COVID-19 mRNA vaccination in Japanese PLWH. NAb titers were assessed in polyclonal IgG fractions by lentiviral-based pseudovirus assays.
View Article and Find Full Text PDFThe ongoing vaccination efforts and exposure to endemic and emerging coronaviruses can shape the population's immunity against this group of viruses. In this study, we investigated neutralizing immunity against endemic and emerging coronaviruses in 200 Tanzanian frontline healthcare workers (HCWs). Despite low vaccination rates (19.
View Article and Find Full Text PDFArticle Synopsis
- Many SARS-CoV-2 variants have developed mutations that impact how the virus infects and evades the immune system.
- Recent research shows that specific mutations (L452R and Y453F) in the virus's spike protein help it escape detection by a certain type of immune response known as HLA-A24-restricted cellular immunity.
- These mutations not only enhance the virus's ability to infect cells but also increase its stability and replication, highlighting a potential ongoing threat from the virus's evolution.
Objectives: Certain human leucocyte antigen (HLA)-B alleles (protective alleles) associate with durable immune control of HIV-1, but with substantial heterogeneity in the level of control. It remains elusive whether viral factors including Nef-mediated immune evasion function diminish protective allele effect on viral control.
Design: The naturally occurring non-Ser variant at position 9 of HIV-1 subtype C Nef has recently exhibited an association with enhanced HLA-B downregulation function and decreased susceptibility to recognition by CD8 T cells.