The effect of Plasmodium falciparum exposure and maternal anti-circumsporozoite protein antibodies on responses to RTS,S/AS01 vaccination in infants and children: an ancillary observational immunological study to a phase 3, randomised clinical trial.

Background: The RTS,S/AS01 malaria vaccine showed lower antibody response and protective efficacy in infants aged 6-12 weeks compared with children aged 5-17 months (for whom this vaccine is recommended). We aimed to study the effect of previous Plasmodium falciparum exposure on the antibody responses to RTS,S/AS01 vaccination in infants and children, and the mediating effect of baseline (including maternal) anti-circumsporozoite protein (CSP) antibodies.

Methods: In this observational study, we included children and infants from six African countries (Burkina Faso, Gabon, Ghana, Kenya, Mozambique, and Tanzania) enrolled in the MAL067 immunology ancillary study of the RTS,S/AS01 phase 3 clinical trial from March 27, 2009, to Jan 21, 2011.

Effect of RTS,S/AS01 vaccine booster dose on cellular immune responses in African infants and children.

RTS,S/AS01, the first approved malaria vaccine, demonstrated moderate efficacy during the phase 3 pediatric trial. We previously investigated cell-mediated immune (CMI) responses following the primary 3-dose immunization and now report responses to the booster dose given 18 months later. Thirty CMI markers were measured by Luminex in supernatants of peripheral blood mononuclear cells from 709 children and infants after RTS,S/AS01 antigen stimulation, and their associations with malaria risk and antibodies one month post-booster and one year later were assessed.

Corrigendum: Digital Intervention Services to Promote HIV Self-Testing and Linkage to Care Services: A Bibliometric and Content Analysis-Global Trends and Future Directions.

[This corrects the article DOI: 10.3389/phrs.2024.

Men's Willingness to Receive Text Messages and Talk with an HIV counselor from the National HIV Hotline in Tanzania for Support with Linkage to Care Following HIV self-testing.

Background: Tanzania faces a significant burden of HIV, with particular challenges in reaching men and ensuring timely linkage to care. To address these issues, HIV self-testing (HIVST) has been implemented to increase HIV testing and the National HIV Hotlines are being considered as a strategy to facilitate linkage to care. This study aimed to assess the willingness of Tanzanian men to receive support from use the National HIV Hotline via mobile phones for HIVST and linkage to care.

Digital Intervention Services to Promote HIV Self-Testing and Linkage to Care Services: A Bibliometric and Content Analysis-Global Trends and Future Directions.

The global burden of HIV remains a critical public health challenge, particularly in sub-Saharan Africa, home to over two-thirds of individuals living with HIV. HIV self-testing (HIVST) has emerged as a promising strategy endorsed by the World Health Organization to achieve UNAIDS targets. Despite its potential, challenges persist in linking self-testers to care post a positive result.

Safety and efficacy of malaria vaccine candidate R21/Matrix-M in African children: a multicentre, double-blind, randomised, phase 3 trial.

Background: Recently, we found that a new malaria vaccine, R21/Matrix-M, had over 75% efficacy against clinical malaria with seasonal administration in a phase 2b trial in Burkina Faso. Here, we report on safety and efficacy of the vaccine in a phase 3 trial enrolling over 4800 children across four countries followed for up to 18 months at seasonal sites and 12 months at standard sites.

Methods: We did a double-blind, randomised, phase 3 trial of the R21/Matrix-M malaria vaccine across five sites in four African countries with differing malaria transmission intensities and seasonality.

Safety and Immunogenicity of Radiation-Attenuated PfSPZ Vaccine in Equatoguinean Infants, Children, and Adults.

The radiation-attenuated Plasmodium falciparum sporozoites (PfSPZ) Vaccine has demonstrated safety and immunogenicity in 5-month-old to 50-year-old Africans in multiple trials. Except for one, each trial has restricted enrollment to either infants and children or adults < 50 years old. This trial was conducted in Equatorial Guinea and assessed the safety, tolerability, and immunogenicity of three direct venous inoculations of 1.

Increased levels of anti-PfCSP antibodies in post-pubertal females versus males immunized with PfSPZ Vaccine does not translate into increased protective efficacy.

Background: While prior research has shown differences in the risk of malaria infection and sickness between males and females, little is known about sex differences in vaccine-induced immunity to malaria. Identifying such differences could elucidate important aspects of malaria biology and facilitate development of improved approaches to malaria vaccination.

Methods: Using a standardized enzyme-linked immunosorbent assay, IgG antibodies to the major surface protein on (Pf) sporozoites (SPZ), the Pf circumsporozoite protein (PfCSP), were measured before and two weeks after administration of a PfSPZ-based malaria vaccine (PfSPZ Vaccine) to 5-month to 61-year-olds in 11 clinical trials in Germany, the US and five countries in Africa, to determine if there were differences in vaccine elicited antibody response between males and females and if these differences were associated with differential protection against naturally transmitted Pf malaria (Africa) or controlled human malaria infection (Germany, the US and Africa).

Health service utilisation during the COVID-19 pandemic in sub-Saharan Africa in 2020: a multicountry empirical assessment with a focus on maternal, newborn and child health services.

Introduction: There are concerns about the impact of the COVID-19 pandemic on the continuation of essential health services in sub-Saharan Africa. Through the Countdown to 2030 for Women's, Children's and Adolescents' Health country collaborations, analysts from country and global public health institutions and ministries of health assessed the trends in selected services for maternal, newborn and child health, general service utilisation.

Methods: Monthly routine health facility data by district for the period 2017-2020 were compiled by 12 country teams and adjusted after extensive quality assessments.

Strong off-target antibody reactivity to malarial antigens induced by RTS,S/AS01E vaccination is associated with protection.

The RTS,S/AS01E vaccine targets the circumsporozoite protein (CSP) of the Plasmodium falciparum (P. falciparum) parasite. Protein microarrays were used to measure levels of IgG against 1000 P.

Safety, immunogenicity and efficacy of PfSPZ Vaccine against malaria in infants in western Kenya: a double-blind, randomized, placebo-controlled phase 2 trial.

The radiation-attenuated Plasmodium falciparum sporozoite (PfSPZ) vaccine provides protection against P. falciparum infection in malaria-naïve adults. Preclinical studies show that T cell-mediated immunity is required for protection and is readily induced in humans after vaccination.

Small and sick newborn care during the COVID-19 pandemic: global survey and thematic analysis of healthcare providers' voices and experiences.

Introduction: The COVID-19 pandemic is disrupting health systems globally. Maternity care disruptions have been surveyed, but not those related to vulnerable small newborns. We aimed to survey reported disruptions to small and sick newborn care worldwide and undertake thematic analysis of healthcare providers' experiences and proposed mitigation strategies.

Nanotechnological immunoassay for rapid label-free analysis of candidate malaria vaccines.

Malaria is a life-threatening epidemic disease with half of the world's population at risk. Although its incidence rate has fallen since 2010, this ratio dramatically stalled between 2014 and 2018. New fast and optimized tools in vaccine analysis and seroconversion testing are critically needed.

Immunogenicity and Protective Efficacy of Radiation-Attenuated and Chemo-Attenuated PfSPZ Vaccines in Equatoguinean Adults.

sporozoite (PfSPZ) Vaccine (radiation-attenuated, aseptic, purified, cryopreserved PfSPZ) and PfSPZ-CVac (infectious, aseptic, purified, cryopreserved PfSPZ administered to subjects taking weekly chloroquine chemoprophylaxis) have shown vaccine efficacies (VEs) of 100% against homologous controlled human malaria infection (CHMI) in nonimmune adults. sporozoite-CVac has never been assessed against CHMI in African vaccinees. We assessed the safety, immunogenicity, and VE against homologous CHMI of three doses of 2.

Efficacy of Single-Dose Primaquine With Artemisinin Combination Therapy on Plasmodium falciparum Gametocytes and Transmission: An Individual Patient Meta-Analysis.

Background: Since the World Health Organization recommended single low-dose (0.25 mg/kg) primaquine (PQ) in combination with artemisinin-based combination therapies (ACTs) in areas of low transmission or artemisinin-resistant Plasmodium falciparum, several single-site studies have been conducted to assess efficacy.

Methods: An individual patient meta-analysis to assess gametocytocidal and transmission-blocking efficacy of PQ in combination with different ACTs was conducted.

Antigen-stimulated PBMC transcriptional protective signatures for malaria immunization.

Identifying immune correlates of protection and mechanisms of immunity accelerates and streamlines the development of vaccines. RTS,S/AS01E, the most clinically advanced malaria vaccine, has moderate efficacy in African children. In contrast, immunization with sporozoites under antimalarial chemoprophylaxis (CPS immunization) can provide 100% sterile protection in naïve adults.

Optimal timing of primaquine to reduce Plasmodium falciparum gametocyte carriage when co-administered with artemether-lumefantrine.

Background: Primaquine is an important gametocytocidal drug that is combined with conventional malaria treatment for prevention of Plasmodium falciparum malaria transmission. Primaquine has been administered together on the first or the last day of conventional treatment but the impact of primaquine timing has never been examined. This study aimed to assess safety, efficacy and optimal timing of single full-dose (0.

Activation of TCR Vδ1 and Vδ1Vδ2 γδ T Cells upon Controlled Infection with in Tanzanian Volunteers.

Our understanding of the human immune response to malaria remains incomplete. Clinical trials using whole-sporozoite-based vaccination approaches such as the Sanaria PfSPZ Vaccine, followed by controlled human malaria infection (CHMI) to assess vaccine efficacy offer a unique opportunity to study the immune response during infection. Diverse populations of T cells that are not restricted to classical HLA (unconventional T cells) participate in the host response during infection.

Increase of Dose Associated With Decrease in Protection Against Controlled Human Malaria Infection by PfSPZ Vaccine in Tanzanian Adults.

Background: A vaccine would be an ideal tool for reducing malaria's impact. PfSPZ Vaccine (radiation attenuated, aseptic, purified, cryopreserved Plasmodium falciparum [Pf] sporozoites [SPZ]) has been well tolerated and safe in >1526 malaria-naive and experienced 6-month to 65-year-olds in the United States, Europe, and Africa. When vaccine efficacy (VE) of 5 doses of 2.

A multiplex qPCR approach for detection of pfhrp2 and pfhrp3 gene deletions in multiple strain infections of Plasmodium falciparum.

The rapid and accurate diagnosis of Plasmodium falciparum malaria infection is an essential factor in malaria control. Currently, malaria diagnosis in the field depends heavily on using rapid diagnostic tests (RDTs) many of which detect circulating parasite-derived histidine-rich protein 2 antigen (PfHRP2) in capillary blood. P.

Concentration and avidity of antibodies to different circumsporozoite epitopes correlate with RTS,S/AS01E malaria vaccine efficacy.

RTS,S/AS01E has been tested in a phase 3 malaria vaccine study with partial efficacy in African children and infants. In a cohort of 1028 subjects from one low (Bagomoyo) and two high (Nanoro, Kintampo) malaria transmission sites, we analysed IgG plasma/serum concentration and avidity to CSP (NANP-repeat and C-terminal domains) after a 3-dose vaccination against time to clinical malaria events during 12-months. Here we report that RTS,S/AS01E induces substantial increases in IgG levels from pre- to post-vaccination (p < 0.

Two cases of long-lasting, sub-microscopic Plasmodium malariae infections in adults from coastal Tanzania.

Background: Malaria is endemic in Tanzania with majority of clinical cases caused by Plasmodium falciparum. Additionally, Plasmodium malariae and Plasmodium ovale spp. are also present and clinical manifestations caused by these infections are not well described.

Safety and Differential Antibody and T-Cell Responses to the Sporozoite Malaria Vaccine, PfSPZ Vaccine, by Age in Tanzanian Adults, Adolescents, Children, and Infants.

In 2016, there were more cases and deaths caused by malaria globally than in 2015. An effective vaccine would be an ideal additional tool for reducing malaria's impact. Sanaria PfSPZ Vaccine, composed of radiation-attenuated, aseptic, purified, cryopreserved (Pf) sporozoites (SPZ) has been well tolerated and safe in malaria-naïve and experienced adults in the United States and Mali and protective against controlled human malaria infection with Pf in the United States and field transmission of Pf in Mali, but had not been assessed in younger age groups.