Tag: Malaria

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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
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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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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

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Paracetamol May Protect Against Kidney Damage in Malaria

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Paracetamol may help protect against kidney damage in patients with malaria, according to a study recently published in Clinical Infectious Diseases.

The study found that for patients with severe malaria caused by the malaria parasite Plasmodium knowlesi (the most common cause of malaria in Malaysia), taking paracetamol regularly for 3 days led to improvements in kidney function when tested one week later.

The findings are important because they will help provide the best possible treatment to patients with severe malaria, said study leader Dr Daniel Cooper.

“Even minor kidney injury can have long-term effects, so anything we can do to minimise kidney injury from malaria will be beneficial for these patients’ long-term outcomes,” Dr Cooper said.

In collaboration with international partners, the study involved 396 people with knowlesi malaria in Sabah, Malaysia.

Assistant Professor Bridget Barber said that in severe malaria, red blood cells can rupture, releasing haemoglobin which can have a toxic impact on kidneys, and it is now believed that paracetamol can help to mitigate these toxic effects.

“These results are consistent with other studies conducted in patients with other forms of malaria, including in adults in Bangladesh, and in children in Africa. Importantly, these findings also suggest that paracetamol may help to protect the kidneys in other conditions that are also associated with rupture of red blood cells,” A/Prof Barber said.

Source: MedicalXpress

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NICD Warns of Malaria Being Misdiagnosed as COVID

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Mosquito
Photo by Егор Камелев on Unsplash

The National Institute for Communicable Diseases has warned that, as South Africa enters its peak malaria season, cases of malaria are being misdiagnosed as COVID. Both malaria and COVID have similar non-specific early symptoms such as fever, chills, headaches, fatigue and muscle pain. Undiagnosed and untreated malaria rapidly progresses to severe illness and can be fatal.

Speaking at a media briefing on Wednesday, principal NICD medical scientist Dr Jaishree Raman said that Gauteng has seen a slight increase of malaria cases recently. 

Dr Raman noted that COVID “has pulled resources from the malaria programmes, reducing active surveillance and case investigation, which is reducing the ability [to] classify cases accurately.”

However, the NICD does not know the exact source of the malaria. “Data cleaning and case classification is ongoing, so at the moment, we cannot say whether the uptick in cases is due to locally-acquired or imported malaria,” she said.

The NICD advises that any individual that prevents with fever or ‘flu-like illness, if they reside in a malaria-risk area in Limpopo, KwaZulu-Natal and Mpumalanga or have travelled to a malaria-risk area, especially Mozambique, in the past six weeks, must be tested for malaria by blood smear microscopy or malaria rapid diagnostic test. If they test positive for malaria, the patient must be started on malaria treatment, immediately.

The NICD also advises patients to remember to inform their healthcare provider of their recent travel, especially to neighbouring countries and malaria risk areas in South Africa.  

‘Taxi malaria’, transmitted by hitch-hiking mosquitoes, should be considered in a patient with unexplained fever who has not travelled to a malaria-endemic area, but is getting progressively sicker, with a low platelet count.

Source: NICD

Categories : VaccinesTags :

World-first Malaria Vaccine Receives WHO Recommendation

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Mosquito
Photo by Егор Камелев on Unsplash

The World Health Organization (WHO) is recommending widespread use of a new malaria vaccine among children in sub-Saharan Africa and in other regions with moderate to high P. falciparum malaria transmission. The vaccine, known as the RTS,S/AS01 (RTS,S or Mosquirix), has been trialled in three countries in a pilot programme involving 800 000 children.

Though the vaccine only offers moderate protection against malaria, with 36% protection against malaria cases among children. One study estimated that even with realistic vaccine coverage, at a constraint of 30 million doses, 5.3 million cases and 24 000 deaths could be prevented among children under five, .

“This is a historic moment. The long-awaited malaria vaccine for children is a breakthrough for science, child health and malaria control,” said WHO Director-General Dr Tedros Adhanom Ghebreyesus. “Using this vaccine on top of existing tools to prevent malaria could save tens of thousands of young lives each year.”

This comes amid stagnation in progress in recent years against the deadly disease. In sub-Saharan Africa, malaria remains a primary cause of childhood illness and death. More than 260 000 African children under the age of five die from malaria annually.

“For centuries, malaria has stalked sub-Saharan Africa, causing immense personal suffering,” said Dr Matshidiso Moeti, WHO Regional Director for Africa. “We have long hoped for an effective malaria vaccine and now for the first time ever, we have such a vaccine recommended for widespread use. Today’s recommendation offers a glimmer of hope for the continent which shoulders the heaviest burden of the disease and we expect many more African children to be protected from malaria and grow into healthy adults.”

The WHO recommends that in the context of comprehensive malaria control the RTS,S malaria vaccine be used for the prevention of P. falciparum malaria in children living in regions with moderate to high transmission as defined by the WHO. This vaccine should be provided in a schedule of 4 doses in children from 5 months of age for the reduction of malaria disease and burden.

The outcome of the pilots informed the recommendation based on data and insights generated from two years of vaccination in child health clinics in Ghana, Kenya and Malawi. Findings include:

  • Vaccine introduction is feasible, improves health and saves lives, with good and equitable coverage of RTS,S seen through routine immunization systems. This occurred even in the context of the COVID pandemic.
  • RTS,S enhances equity in access to malaria prevention.
  • Data from the pilot programme showed that more than two-thirds of children in the 3 countries who are not sleeping under a bednet are benefitting from the RTS,S vaccine.
  • Layering of tools results in over 90% of children benefitting from at least one preventive intervention (insecticide treated bednets or the malaria vaccine).
  • Strong safety profile: To date, more than 2.3 million doses of the vaccine have been administered in 3 African countries – the vaccine has a favorable safety profile.
  • No negative impact on uptake of bednets, other childhood vaccinations, or health seeking behavior for febrile illness. In areas where the vaccine has been introduced, there has been no decrease in the use of insecticide-treated nets, uptake of other childhood vaccinations or health seeking behavior for febrile illness.
  • High impact in real-life childhood vaccination settings: Significant reduction (30%) in deadly severe malaria, even when introduced in areas where insecticide-treated nets are widely used and there is good access to diagnosis and treatment.
  • Highly cost-effective: Modelling estimates that the vaccine is cost effective in areas of moderate to high malaria transmission.

Next steps for the WHO-recommended malaria vaccine will include funding decisions from the global health community for broader rollout, and country decision-making on whether to adopt the vaccine as part of national malaria control strategies.

The pilot programme was financed through collaboration between Gavi, the Vaccine Alliance; the Global Fund to Fight AIDS, Tuberculosis and Malaria; and Unitaid.

Source: WHO

Categories : Antibiotics Obstetrics & GynaecologyTags :

Azithromycin Protects Pregnancies in Countries with Malaria

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A review has found that the common antibiotic azithromycin taken during pregnancy reduces low birth weight and premature births in countries where malaria is endemic.

The systematic review of 14 studies in African and Asia, published in The Lancet EClinicalMedicine, found that azithromycin, reduced low birth weight and prematurity but didn’t lower infant deaths, infections and hospital admissions.

Azithromycin, an inexpensive antibiotic widely used to treat chest and ear infections, has been specifically used in the past in pregnancy to treat STIs and, alongside other antimalarial drugs, to prevent adverse consequences of malaria on maternal and foetal outcomes and caesarean wound infections.

Murdoch Children’s Research Institute (MCRI) researcher Dr Maeve Hume-Nixon said it was not clear whether azithromycin would improve perinatal and neonatal outcomes in non-malaria endemic settings, and the potential harm on stillbirth rates needed further investigation.

Dr Hume-Nixon said these findings emphasised the importance of similar MCRI-led research currently being done in Fiji.

“This review found that there was uncertainty about the potential benefits of this intervention on neonatal deaths, admissions and infections, and potential harmful effects on stillbirth despite biological reasons why this intervention may have benefits for these outcomes,” she said.

“Therefore, results from studies like ours underway in Fiji will help to better understand the effect of this intervention on these outcomes.”

The Bulabula MaPei study is a randomised controlled clinical trial testing if azithromycin given to women in labour, prevents maternal and infant infections.

Globally, infections account for 21% of 2.4 million neonatal deaths per year and 52% of all under-five deaths, disproportionately occurring in low- and middle-income countries.

About five million cases of pregnancy-related infections occur in mothers each year as well, resulting in 75 000 maternal deaths.

MCRI Professor Fiona Russell said the large clinical trials in Africa and Asia, along with the MCRI-led trial in Fiji, were likely to inform global policy related to maternal child health and hopefully benefit infants and mothers around the world.

“Administration of azithromycin during labour may be a cheap and simple intervention that could be used to improve neonatal death rates in low and middle-income countries, alongside strengthening of maternal child health services,” she said. “This study, together with other large clinical trials, will add to evidence for the consideration of new international maternal and child health guidelines.”

Source: Murdoch Childrens Research Institute