Functional antibody responses to SARS-CoV-2 variants before and after booster vaccination among adults in Ghana.

COVID-19 booster vaccinations are needed to enhance waning immunity and the emergence of new variants. In Africa, where COVID-19 vaccine coverage is low, there is a paucity of data on COVID-19 vaccine-induced immunity, particularly in the post-omicron era. This study examined the functional activity of vaccine-induced antibody responses against different variants before and after booster vaccinations in adults in Ghana, between November 2022 and February 2023.

Deposition of complement regulators on the surface of Plasmodium falciparum merozoites depends on the immune status of the host.

Plasmodium falciparum is responsible for the majority of malaria cases and deaths worldwide. In malaria endemic areas, natural immunity to blood stage infection is acquired over several exposures to the parasite and is thought to rely on antibodies. Antibodies can protect from severe disease through different effector functions, with complement activation lately emerging as an important feature of protective humoral responses to malaria.

Identifying risk factors for loss to follow-up in adults living with HIV in a high-burden district in Ghana.

Background: Loss to follow-up (LTFU) in the care of persons living with HIV hinders the effectiveness of treatment strategies and undermines global health initiatives to achieve targets such as the 95-95-95 goals. Identifying risk factors for LTFU will help develop effective interventions that enhance long-term outcomes for people living with HIV (PLWHIV). Thus, this study aimed to explore the risk factors influencing LTFU among PLWHIV in a high-burden district in Ghana.

Efficient transplacental transfer of SARS-CoV-2 antibodies between naturally exposed mothers and infants in Accra, Ghana.

We aimed to determine SARS-CoV-2 antibody seropositivity among pregnant women and the transplacental transfer efficiency of SARS-CoV-2-specific antibodies relative to malaria antibodies among SARS-CoV-2 seropositive mother-cord pairs. This cross-sectional study was conducted in Accra, Ghana, from March to May 2022. Antigen- specific IgG antibodies against SARS-CoV-2 (nucleoprotein and spike-receptor binding domain) and malarial antigens (circumsporozoite protein and merozoite surface protein 3) in maternal and cord plasma were measured by ELISA.

Atypical memory B cell frequency correlates with antibody breadth and function in malaria immune adults.

Clinical immunity to malaria develops slowly after repeated episodes of infection and antibodies are essential in naturally acquired immunity against malaria. However, chronic exposure to malaria has been linked to perturbation in B-cell homeostasis with the accumulation of atypical memory B cells. It is unclear how perturbations in B cell subsets influence antibody breadth, avidity, and function in individuals naturally exposed to malaria.