Tag: Malaria

Categories : Diseases, Syndromes and Conditions General InterestTags :

H3D’s Pioneering Research Adds Hope to the Fight against Malaria 

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Members of the University of Cape Town’s Holistic Drug Discovery and Development Centre H3D

A formidable disease that has plagued humanity for centuries, malaria has exacted a heavy toll on human lives, disrupting communities and hindering socio-economic progress across some of the most vulnerable regions of the world, particularly the African continent.  

With its stealthy transmission through the bites of infected mosquitoes, malaria has earned the dubious reputation of being one of the deadliest vector-borne diseases on the planet. So much so that the World Health Organization’s World Malaria Report reveals that malaria cases are on the rise, with instances rising from 245 million cases in 2020 to over 247 million a year later1. 

With an estimated 619,000 people succumbing to the disease in 20211, it remains a defining challenge for global healthcare systems. However, through the unyielding persistence and spirit of medical innovation and scientific ingenuity exemplified by research facilities such as the University of Cape Town’s Holistic Drug Discovery and Development Centre (H3D), solutions to mitigate the severity of malaria are on the horizon.  

“As the first and only integrated drug discovery platform on the African continent, H3D’s mission is to discover and develop innovative life-saving medicines for diseases that predominantly affect African patients,” explains Bada Pharasi, CEO of the Innovative Pharmaceutical Association of South Africa (IPASA).

H3D’s focus on building Africa-specific models aims to improve treatment outcomes in African patients and to educate and train a critical mass of skilled African-based drug discovery scientists. H3D’s scientific output and research model includes attracting international investment in local innovative pharmaceutical research and development (R&D) across the African continent to address the disproportionately high global disease burden. Importantly, H3D targets critical infectious diseases, including tuberculosis, antibiotic-resistant microbial diseases, and malaria. 

“Given the vulnerability of many of the African populations, the continent accounted for 95% of malaria cases and 96% of malaria deaths in 20211. Accordingly, continued antimalarial drug research and development, such as the studies conducted by H3D, is important to prevent and treat the millions of cases that arise each year, all of which have consequences on both the health and socioeconomic development of the continent,” adds Pharasi.

Since the official launch of H3D’s programs in April 2011, there have been notable advances in innovative drug discovery projects. The centre has demonstrated a strong track record with multiple chemical series discovered and being progressed at H3D in each stage of the drug development pipeline.

A significant achievement reached by H3D was the discovery of the malaria clinical candidate, MMV390048, which reached phase II human trials in African patients. This was the first ever small molecule clinical candidate, for any disease, researched on African soil by an African drug discovery research unit. 

According to Dr Candice Soares de Melo, Chief Investigator at H3D, the centre’s current anti-malarial programmes will focus on the identification of quality leads suitable for optimisation and candidate selection as potential agents for the treatment of uncomplicated Plasmodium falciparum malaria, ideally with additional activity against liver-stage parasites to offer protection and prevent relapses (in case of malaria caused by the species Plasmodium vivax), as well as blocking the transmission of the disease. 

“A critical component of the research conducted at H3D is to develop medicines that are safe and sufficiently tolerated to be given to the widest range of recipients, including infants and pregnant women,” says Soares de Melo.

Besides the potential benefits of providing a new cure for malaria, H3D serves as a catalyst for training scientists in infectious disease research and influencing the R&D environment in Africa.  As part of its partnership with the South African Medical Research Council, H3D has worked to mentor and develop scientists at other African universities, including those at Historically Disadvantaged Institutions (HDIs) within South Africa. 

Furthermore, apart from strengthening drug discovery innovation at UCT, the centre has also taken a lead role in partnership with the Bill & Melinda Gates Foundation in catalysing drug discovery across sub-Saharan Africa, with upwards of 16 university research groups working on malaria and tuberculosis drug discovery. 

“An example of this is the Phase 1 clinical trial for the H3D clinical candidate MMV390048, which was carried out at the UCT Division of Clinical Pharmacology,” adds Soares de Melo. 

Another is the MATRIX independent special project, which has the potential to transform local drug manufacturing across the continent. Funded by the United States Agency for International Development (USAID), the project aims to pilot cost-effective local manufacture of antiretroviral Active Pharmaceutical Ingredients using flow reactor technology.

“Should Africa intend on a path to self-sufficiency, it’s important to drive continued investment in health innovations developed for and by Africa.

“We support the research efforts of H3D, and strongly believe that now is the time to take a deliberate and systematic approach to develop new capabilities, transfer technologies, leverage partnerships and networks, and train scientists, all while delivering on drug discovery projects to help address the continent’s, and the world’s, greatest health challenges,” concludes Pharasi.

For more information, visit https://h3d.uct.ac.za/ or contact Candice Soares de Melo at candice.soaresdemelo@uct.ac.za.

Categories : Skeletal SystemTags :

AI Finds that an Antimalarial Drug might Treat Osteoporosis Too

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Photo by Ekamelev on Unsplash

Using a deep learning algorithm, which is a kind of artificial intelligence (AI), researchers reporting have found that dihydroartemisinin (DHA), an antimalarial drug and derivative of a traditional Chinese medicine, could treat osteoporosis as well. Publishing their findings in ACS Central Science, the team showed that in mice, DHA effectively reversed osteoporosis-related bone loss.

In healthy people, there is a balance between the osteoblasts that build new bone and osteoclasts that break it down. Current treatments for osteoporosis primarily focus on slowing the activity of the ‘wrecking crew’ of osteoclasts. But osteoblasts, or more specifically, their precursors known as bone marrow mesenchymal stem cells (BMMSCs), could be the basis for a different approach. During osteoporosis, these multipotent cells tend to turn into fat-creating cells instead, but they could be reprogrammed to help treat the disease. Previously, Zhengwei Xie and colleagues developed a deep learning algorithm that could predict how effectively certain small-molecule drugs reversed changes to gene expression associated with the disease. This time, joined by Yan Liu and Weiran Li, they wanted to use the algorithm to find a new treatment strategy for osteoporosis that focused on BMMSCs.

The team ran their program on a profile of differently expressed genes in newborn and adult mice. One of the top-ranked compounds identified was DHA, a derivative of artemisinin and a key component of malaria treatments. Administering DHA extract for six weeks to mice with induced osteoporosis significantly reduced bone loss in their femurs and nearly completely preserved bone structure. To improve delivery, the team designed a more robust system using injected, DHA-loaded nanoparticles. Bones of mice with osteoporosis that received the treatment were similar to those of the control group, and the treatment showed no evidence of toxicity. In further tests, the team determined that DHA interacted with BMMSCs to maintain their stemness and ultimately produce more osteoblasts. The researchers say that this work demonstrates that DHA is a promising therapeutic agent for osteoporosis.

Source: American Chemical Society

Categories : Environmental Effects GeneticsTags :

Scientists Abuzz over a Genetic Way to Deafen Mosquitoes

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Specific receptors in the ears of mosquitoes have been revealed to modulate their hearing, finds a new study led by researchers at UCL and University of Oldenburg. Since male mosquitoes need to hear female mosquitoes is a crucial factor in their reproduction, this discovery could help develop new insecticides and control the spread of harmful diseases, such as malaria, dengue, and yellow fever.

In the study, published in Nature Communications, the researchers focused on a signalling pathway involving a molecule called octopamine. They demonstrated that it is key for mosquito hearing and mating partner detection, and so is a potential new target for mosquito control.

Male mosquitoes acoustically detect the buzz generated by females within large swarms that form transiently at dusk.

As swarms are potentially noisy, mosquitoes have developed highly sophisticated ears to detect the faint flight tone of females amid hundreds of mosquitoes flying together.

However, the molecular mechanisms by which mosquito males ‘sharpen their ears’ to respond to female flight tones during swarm time have been largely unknown.

The researchers looked at the expression of genes in the mosquito ear and found that an octopamine receptor specifically peaks in the male mosquito ear when mosquitoes swarm.

The study found that octopamine affects mosquito hearing on multiple levels. It modulates the frequency tuning and stiffness of the sound receiver in the male ear, and also controls other mechanical changes to boost the detection of the female.

The researchers demonstrated that the octopaminergic system in the mosquito ear can be targeted by insecticides. Mosquito mating is a bottleneck for mosquito survival, so identifying new targets to disrupt it is key to controlling disease-transmitting mosquito populations.

Source: University College London

Categories : Diseases, Syndromes and ConditionsTags :

Inflammation Impedes the Development of Malaria Parasites

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Researchers have found that inflammation can slow down the development of malaria parasites in the bloodstream, which may lead to a new strategy for preventing or limiting severe disease.

The malaria-causing Plasmodium parasites invade and multiply within red blood cells. Studies have shown that the parasites can rapidly sense and respond to conditions within the host by intimately syncing with their internal body clocks. While it is known that the body’s nutrient levels and daily circadian rhythms affect the parasites’ development, little was known about the impact of host inflammation on the parasites.

This animal-model study, led by the Peter Doherty Institute for Infection and Immunity (Doherty Institute) and the Kirby Institute and published in the journal mBio, reveals that when the body’s immune system responds to inflammation it alters the plasma’s chemical composition, directly impeding the maturation of the Plasmodium parasites in the bloodstream.

University of Melbourne’s Associate Professor Ashraful Haque, a senior author of the paper, said this work highlights the captivating dynamic of the host-parasite relationship.

“First, we discovered that inflammation in the body prevented the early stage of the parasites from maturing. We also noticed that inflammation triggered significant changes in the composition of the plasma – we were actually quite surprised by the magnitude of these changes,” said Associate Professor Haque.

“As we dug deeper, we found substances in the altered plasma that, we believe, are what may inhibit parasite growth in the body. This work reveals a new mechanism that slows down the malaria parasite’s development in the bloodstream. Our research was done using animal models, so it would be really interesting to study if such inhibitory mechanisms occur in humans too.”

Dr David Khoury, co-senior author of the paper, said the scientists found a remarkable response by the parasites to the changes in their environment.

“Parasites residing in red blood cells rapidly sense and respond to their new environment, showing fascinating adaptability. Using cutting-edge genome sequencing technology, we observed that even after just four hours in this changed plasma, the parasites adjusted their genetic and protein activity, resulting in slower maturation within red blood cells. It’s almost like the parasites actively sense an inhospitable host environment, and as a result trigger a coping mechanism,” said Dr Khoury.

“We believe this is the first study to show that inflammation can change how individual parasites behave genetically in the body.”

Professor Miles Davenport, co-senior author of the paper, said this work on the interaction between systemic host inflammation and malaria parasite maturation offers several potential benefits.

“This study, while based on animal models, broadens our understanding of malaria. It provides a foundation for further investigations into the specific mechanisms involved in the modulation of parasite maturation by inflammation, and opens avenues for future studies to explore the identified inhibitory factors, genetic changes and their implications for malaria development,” said Professor Davenport.

Source: The Peter Doherty Institute for Infection and Immunity

Categories : Diseases, Syndromes and ConditionsTags :

New Monoclonal Antibody Prevents Malaria Infection in African Adults

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Mosquito, a malaria parasite vector
Photo by Егор Камелев on Unsplash

One dose of a new monoclonal antibody safely protected healthy, non-pregnant adults from malaria infection during the malaria season in Mali. The antibody was up to 88.2% effective at preventing infection over a 24-week period, demonstrating for the first time that a monoclonal antibody can prevent malaria infection in an endemic region. These findings were published in The New England Journal of Medicine.

The only WHO-recommended vaccine against vaccine, RTS,S (Mosquirix), provides partial protection against clinical malaria during the early years of life when given to children aged 5 to 17 months in four doses over a 20-month period. Other drugs consisting of small chemical compounds that effectively prevent malaria infection are also available for infants and young children as well as travellers. The requirement for frequent dosing of these drugs can limit adherence, however, and the emergence of drug resistance may also limit their usefulness. Thus, there is an urgent need for new, fast-acting, infrequently dosed interventions that safely provide strong protection against malaria infection.

Malaria is caused by Plasmodium parasites, which mosquitos inject into into the skin and bloodstream in a form called sporozoites. These travel to the liver, where they mature and multiply before spreading throughout the body via the bloodstream to cause illness. P. falciparum is the Plasmodium species most likely to result in severe malaria infections, which, if not promptly treated, may lead to death.

The Phase 2 NIAID-USTTB trial evaluated the safety and efficacy of a one-time, intravenous infusion of a monoclonal antibody called CIS43LS. This antibody was previously shown to neutralise the sporozoites of P. falciparum in the skin and blood before they could infect liver cells. Researchers led by Robert A. Seder, MD, isolated a naturally occurring form of this antibody from the blood of a volunteer who had received an investigational malaria vaccine, and then modified the antibody to extend the length of time it would remain in the bloodstream.

The study team for the Phase 2 trial enrolled 369 healthy, non-pregnant adults aged 18 to 55 years in the rural communities of Kalifabougou and Torodo in Mali, where intense P. falciparum transmission typically occurs from July through December each year.

The first part of the trial assessed the safety of three different intravenous doses of CIS43LS – 5mg/kg of body weight, 10 mg/kg and 40 mg/kg – in 18 study participants, with six participants per dose level. The study team followed these participants for 24 weeks and found the antibody infusions were safe and well-tolerated.

The second part of the trial assessed the efficacy of two different doses of CIS43LS compared to a placebo. Three hundred and thirty participants were assigned at random to receive either 10mg/kg of the antibody, 40mg/kg, or a placebo by intravenous infusion. No one knew who was assigned to which group until the end of the trial. The study team followed these individuals for 24 weeks, testing their blood for P. falciparum weekly for the first 28 days and every two weeks thereafter. Any participant who developed symptomatic malaria during the trial received standard treatment from the study team.

The investigators analysed the efficacy of CIS43LS two ways. Based on the time to first P. falciparum infection over the 24-week study period, the high dose (40 mg/kg) of CIS43LS was 88.2% effective at preventing infection and the lower dose (10 mg/kg) was 75% effective. An analysis of the proportion of participants infected with P. falciparum at any time over the 24-week study period found the high dose was 76.7% at preventing infection and the lower dose was 54.2% effective.

“These first field results demonstrating that a monoclonal antibody safely provides high-level protection against intense malaria transmission in healthy adults pave the way for further studies to determine if such an intervention can prevent malaria infection in infants, children, and pregnant women,” Dr Seder said. “We hope monoclonal antibodies will transform malaria prevention in endemic regions.”

Dr Seder and colleagues have developed a second antimalarial monoclonal antibody, L9LS, that is much more potent than CIS43LS and therefore can be administered in a smaller dose as a more convenient subcutaneous injection. An early-phase NIAID trial of L9LS in the United States found that the antibody was safe and prevented malaria infection for 21 days in 15 out of 17 healthy adults exposed to P. falciparum in a carefully controlled setting. Two larger, NIAID-sponsored Phase 2 trials assessing the safety and efficacy of L9LS in infants, children and adults are underway in Mali and Kenya.

Source: NIH/National Institute of Allergy and Infectious Diseases

Categories : VaccinesTags :

Oxford’s New Malaria Vaccine is ‘World Changing’

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Mosquito, a malaria parasite vector
Photo by Егор Камелев on Unsplash

A malaria vaccine developed by Oxford University has been described as “world changing” following its successful trial in children in Burkina Faso. Their results of their double-blind randomised controlled trial were published yesterday in The Lancet Infectious Diseases.

The researchers had previously reported that in children, the R21/Matrix-M malaria vaccine reached the WHO-specified goal of 75% or greater efficacy over 12 months.

To test the immunogenicity, and efficacy results at 12 months after administration of a booster vaccination, the researchers conducted a trial was done in children aged 5–17 months in Burkina Faso, who had written informed consent provided by their caregivers. Eligible children were randomised to receive three vaccinations of either 5 μg R21/25 μg Matrix-M, 5 μg R21/50 μg Matrix-M, or a control vaccine (the Rabivax-S rabies vaccine) before the malaria season, with a booster dose 12 months later. Exclusion criteria included any existing clinically significant comorbidity or receipt of other investigational products.

Vaccine safety, efficacy, and a potential correlate of efficacy with immunogenicity, measured as anti-NANP antibody titres, were evaluated over one year following the first booster vaccination. Efficacy analyses were performed for all participants who received the primary series of vaccinations and a booster vaccination.

Between June 2, and July 2, 2020, 409 children returned to receive a booster vaccine, which was the same received in the primary series of vaccinations. R21/Matrix-M had a favourable safety profile and was well tolerated. Vaccine efficacy remained high in the high adjuvant dose (50 μg) group, similar to previous findings at one year after the primary series of vaccinations. Following the booster vaccination, 51% of children receiving R21/Matrix-M with low-dose adjuvant, 39% of children receiving the same but with high-dose adjuvant, and 86% of 140 children who received the rabies vaccine developed clinical malaria by 12 months.

Vaccine efficacy was 71% in the low-dose adjuvant group and 80% in the high-dose adjuvant group. In the high-dose adjuvant group, vaccine efficacy against multiple episodes of malaria was 78%, and 2285 cases of malaria were averted per 1000 child-years at risk among vaccinated children in the second year of follow-up. Among these participants, at 28 days following their last R21/Matrix-M vaccination, titres of malaria-specific anti-NANP antibodies correlated positively with protection against malaria in both the first year of follow-up (Spearman’s ρ –0·32 [95% CI –0·45 to –0·19]; p = 0·0001) and second year of follow-up (–0·20 [–0·34 to –0·06]; p = 0·02).

A booster dose of R21/Matrix-M at 1 year following the primary three-dose regimen maintained high efficacy against first and multiple episodes of clinical malaria. Furthermore, the booster vaccine induced antibody concentrations that correlated with vaccine efficacy. The trial is ongoing to assess long-term follow-up of these participants and the value of further booster vaccinations.

Speaking to BBC News, Prof Katie Ewer said that “this is not like COVID where we have seven vaccines straight away that will work… it’s much, much harder”. This malaria vaccine is the 14th that she has worked on, and it was “incredibly gratifying” to get this far and “the potential achievement that this vaccine could have if it’s rolled out could be really world-changing”.

The Oxford-developed vaccine shares similarities with the current, approved malaria vaccine from GSK: both target the first stage of the parasite’s lifecycle by intercepting it before it can establish itself in the liver.

The vaccines use a combination of proteins from the malaria parasite and the hepatitis B virus, but the Oxford vaccines has a more malaria proteins, which may help the immune system to focus on malaria rather than the hepatitis.

The trial is continuing for a further 2 years to assess both the potential value of additional booster vaccine doses and longer-term safety.

Categories : Diseases, Syndromes and ConditionsTags :

Early Sensing of Malaria in the Brain Leads to Cerebral Malaria

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Colourised scanning electron micrograph of red blood cell infected with malaria parasites, which are colourised in blue. The infected cell is in the centre of the image area. To the left are uninfected cells with a smooth red surface. Credit: National Institute of Allergy and Infectious Diseases, NIH

A recent study published in PNAS revealed that endothelial cells in the brain are able to sense the infection by the malaria parasite at an early phase, triggering the inflammation underlying cerebral malaria. This discovery identified new targets for adjuvant therapies that could restrain brain damage in initial phases of the disease and avoid neurological sequelae.

Cerebral malaria is a severe complication of infection with Plasmodium falciparum, the most lethal of the parasites causing malaria. This form of the disease manifests through impaired consciousness and coma and affects mainly children under 5, being one of the main causes of death in this age group in countries of Sub-Saharan Africa. Survivors are frequently affected by debilitating neurological sequelae, such as motor deficits, paralysis, and speech, hearing, and visual impairment.

To prevent certain molecules and cells from reaching the brain, which would disturb its normal functioning, endothelial cells forming a tight barrier between the blood and this organ. Cerebral malaria results from an unrestrained inflammatory response to infection which leads to significant alterations in this barrier and, consequently, neurological complications.

Over the last years, specialists in this field have turned their attention to a molecule, named interferon-β, which seems to be associated with this pathological process. So called for interfering with viral replication, this highly inflammatory molecule has two sides: it can either be protecting or cause tissue destruction. It is known, for example, that despite its antiviral role in COVID-19, at a given concentration and phase of infection, it can cause lung damage. A similar dynamic is thought to occur in cerebral malaria. However, we still don’t know what leads to the secretion of interferon-β, nor the main cells involved.

The present study revealed that endothelial cells in the brain play a crucial role, being able to sense the infection by the malaria parasite at an early phase. These detect the infection through an internal sensor which triggers a cascade of events, starting with the production of interferon-β. Next, they release a signalling molecule that attracts cells of the immune system to the brain, initiating the inflammatory process.

To reach these conclusions, researchers used mice that mimic several symptoms described in human malaria and a genetic manipulation system that allowed them to delete this sensor in several types of cells. When they deleted this sensor in brain endothelial cells, the animals’ symptoms were not as severe with lower mortality. They then realised these brain cells contributed greatly to the pathology of cerebral malaria. “We thought brain endothelial cells acted in a later phase, but we ended up realising that they are participants from the very beginning”, explained Teresa Pais, a post-doctoral researcher at the IGC and first author of the study. “Normally we associate this initial phase of the response to infection with cells of the immune system. These are already known to respond, but cells of the brain, and maybe other organs, also have this ability to sense the infection because they have the same sensors.”

But what really surprised the researchers was the factor activating the sensor and triggering this cell response. This factor is nothing more nothing less than a by-product of the activity of the parasite. Once in the blood, the parasite invades the host’s red blood cells, where it multiplies. Here, it digests haemoglobin, a protein that transports oxygen, to get nutrients. During this process, a molecule named haeme is formed and it can be transported in tiny particles in the blood that are internalised by endothelial cells. When this happens, haeme acts as an alarm for the immune system. “We weren’t expecting that haeme could enter cells this way and activate this response involving interferon-β in endothelial cells”, the researcher confessed.

This six-year project allowed the researchers to identify a molecular mechanism that is critical for the destruction of brain tissue during infection with the malaria parasite and, with that, new therapeutic targets. “The next step will be to try to inhibit the activity of this sensor inside the endothelial cells and understand if we can act on the host’s response and stop brain pathology in an initial phase,” explained principal investigator Carlos Penha Gonçalves. “If we could use inhibitors of the sensor in parallel with antiparasitic drugs maybe we could stop the loss of neuronal function and avoid sequelae which are a major problem for children surviving cerebral malaria.”

Source: Instituto Gulbenkian de Ciência (IGC)

Categories : Diseases, Syndromes and Conditions VaccinesTags :

Why The Malaria Vaccine Quickly Loses its Effectiveness

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Image source: Ekamalev at Unsplash

More than 600 000 people worldwide still die from malaria every year, according to the WHO. The vast majority of fatal cases of malaria are caused by the single-celled pathogen Plasmodium falciparum, which so far has only one approved vaccine against it, and its efficacy, which is already rather low, is also short-lived. A new study in Science Immunology may have the explanation: a lack of cross-reactivity in T helper cells.

The vaccine targets CSP, the quantitatively dominant protein on the surface of the “sporozoites”. Sporozoites are the stage of the malaria pathogen which is transmitted with the bite of the mosquito and enters human blood. “To improve the vaccine, we need to understand which protective antibodies are induced by the immunisation. But the production of such antibodies depends to a large extent on help from the so-called follicular T helper cells,” explained Dr Hedda Wardemann, immunologist and senior author of the study. “They ensure that B cells transform into antibody-producing plasma cells and memory B cells.”

To study the T helper cell response against CSP in detail, Dr Wardemann’s team examined the blood of volunteers infected with killed P. falciparum sporozoites from the vaccine strain. The volunteers were of European descent and had no prior contact with malaria pathogens. The researchers analysed the induced Plasmodium-specific follicular T helper cells at the single cell level. They focused on which sequences of CSP are recognised by the T helper cells’ receptors.

The analyses revealed that the T-cell receptors mainly targeted amino acids 311 to 333 of the CSP. But the researchers were stunned by another finding: there was virtually no cross-reactivity between the individual T-cell clones. “The receptors highly specifically bind only the CSP epitopes of the vaccine strain used. Even deviations of only a single amino acid component were not tolerated in some cases,” Dr Wardemann explained.

The immunologist points out that in the natural population of P. falciparum, sequence polymorphisms occur to a high degree in this region of the CSP. “The specificity of the T-cell clones prevents the constantly recurring natural infections with the pathogen from acting as a natural ‘booster.’ This could possibly explain why the protective effect of the malaria vaccine wears off so quickly,” Dr Wardemann said. The researcher recommends that further development of the vaccine should test whether inducing a broader spectrum of T helper cells could generate longer-lasting immune protection.

Source: German Cancer Research Centre

Categories : VaccinesTags :

Rollout of World’s First Malaria Vaccine in Sub-Saharan Africa

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Mosquito, a malaria parasite vector
Photo by Егор Камелев on Unsplash

The world’s first malaria vaccine will soon be available across sub-Saharan Africa, according to PATH, partners of the vaccine developers, as positive results from the pioneering jab pile up.

The vaccine, known as RTS,S/AS01E and commercialised under the brand name Mosquirix, targets children as over three quarters of malaria deaths occur in under-five-year olds, according to the latest report from the WHO.

Findings from a WHO pilot held in Ghana, Kenya and Malawi, showed that the pioneering vaccine caused a significant reduction in severe malaria and hospitalisation among vaccinated children.

It means more countries in sub-Saharan Africa will soon receive the vaccine, says John Bawa, Africa lead for vaccine implementation at Program for Appropriate Technology in Health (PATH).

These findings pave the way for an expanded distribution scheme that will see countries like Mozambique, Nigeria and Zambia receive the vaccines, said Bawa during a webinar held in commemoration of World Malaria Day.

“The next is to deploy the vaccine to other endemic countries. Countries that are interested in the vaccine are expected to apply to GAVI from June to September,” he said at the webinar organised by the African Media and Malaria Research Network (AMMREN), PATH and Kintampo Health Research Centre (KHRC).

“Countries like Mozambique, Uganda, Zambia and Nigeria have already written officially to express interest for the vaccine,” Bawa said.

He said malaria vaccine coverage in Malawi was at 88% in 2020 and 93% in 2021. In Ghana, it was 71% in 2020 and 76% in 2021 and in Kenya, it was 69% in 2020 and 83% in 2021.

“These numbers indicate strong community demand and capacity of childhood vaccination platforms to effectively deliver the vaccine to children,” said Bawa.

Currently, 1 million children in Ghana, Kenya and Malawi have received at least one dose of the first malaria vaccine.

These vaccines were distributed in a pilot scheme organized by WHO. The organisation has now recommended the vaccine for use among children in areas with moderate to high transmission rate of malaria.

“This vaccine is not just a scientific breakthrough, it is life-changing for families across Africa. It demonstrates the power of science and innovation for health,” WHO Director-General Dr Tedros Adhanom Ghebreyesus said.

Vaccine procurement

In an arrangement to boost vaccine supply and coverage, GlaxoSmithKline, producers of the RTS,S vaccine, will transfer technology and patent to Bharat Biotech in India to manufacture the vaccines.

The WHO, in a press release, said more than US$155 million has been secured from to support the introduction, procurement and delivery of the malaria vaccine for Gavi-eligible countries in sub-Saharan Africa.

The organisation said it would provide guidance for countries that are considering the use of vaccines for the reduction childhood illnesses and deaths from malaria.

“For some countries, Gavi is paying about 80% [of the] cost of the vaccine, while it is expected that the country’s government would pay the [remaining] 20%,” Bawa said.

Wellington Oyibo, director of the Centre for Malaria Diagnosis, Research, Capacity Building and Policy at the University of Lagos, urged African leaders to ensure that their counterpart funds are available to purchase the vaccine.

He said the Nigerian government and the Prince Ned Nwoko Foundation malaria eradication project have applied to purchase the vaccine for Nigerian children.

Oyibo said while the initial rollout of the vaccine may not go around the country, the Nigerian government selected states with the highest malaria burden to begin with.

Reproduced under a Creative Commons Attribution License.

Source: SciDev.Net

Categories : Diseases, Syndromes and ConditionsTags :

Malaria’s Growing Resistance Requires New Insight

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Mosquito, a malaria parasite vector
Photo by Егор Камелев on Unsplash

To deal with malaria’s growing resistance to existing drugs, researchers are exploring new areas of the deadly parasite’s life cycle. Research published in PLOS Pathogens has identified key processes the malaria parasite uses to remodel blood cells it hides inside.

Senior author Paul Gilson, an associate professor at Burney University, said the growing resistance to antimalarial medicines needs to be addressed soon to avoid serious treatment failures in the future.

“It’s only a matter of time before resistance becomes so bad that current measures perhaps become worthless,” he said.

“Current drugs tend to target very similar things. By discovering new targets and developing drugs to these, we can hopefully overcome resistance.

“Our research identifies processes in the parasites that are essential for its survival. And the more we understand about those processes, the better position we’re in to develop new treatments to block those processes.”

The research, A/Prof Gilson explains, looked into the nature of malaria parasites, particularly their need to renovate their host blood cells to grow rapidly and to escape the immune system.

The dynamic is analogous to an international arrivals terminal in need of better security.

“The renovations are carried out by special exported proteins made by the parasite that are only allowed to travel into the blood cell if they have the right passport,” he said.

“We used to think that gateways around the parasite called PTEX acted like immigration officers at the airport only allowing exported proteins with the right passports to pass through.

“What this study now shows is that the immigration officers appear to leave the airport and travel inside the parasites to check the exported protein passports not long after they are first made.

“The officers then pair up with their exported proteins and take them to the airport to let them go straight through into the blood cells.”

A/Prof Gilson said that hopefully, a greater understanding of the ways parasite proteins enter and modify blood cells could result in new drugs that block exported proteins from carrying out essential renovations to their blood cells.

The COVID pandemic has disrupted and set back malaria elimination programs in several countries, making the need for new drug developments to combat the disease all the more vital.

“Many countries only have very limited resources, and it’s estimated that there’s been quite a big increase in the number of malaria cases around the world because so much effort has been diverted to combat COVID,” he said.

Even though COVID has taken the global spotlight, A/Prof Gilson said that malaria is still a major issue. In 2020 there were an estimated 241 million cases of malaria worldwide, with an estimated 627 000 deaths, according to World Health Organization figures.

A/Prof Gilson said that over recent years significant inroads have been made in eliminating malaria, pointing out that annual death rates were in the millions at the start of the 21st century.

“We can’t let COVID undermine all the great work that’s been achieved over the years, as we aim to one day totally eliminate malaria.”

“Research into new drugs to combat malaria parasites, which are becoming resistant to existing drugs, is a crucial part of these efforts.”

Source: Burnet Institute