New breakthrough: 3D printed ferroelectric materials proven to eliminate harmful bacteria including E coli

New fabrication technique gives materials antimicrobial properties, with scope to improve safety of implants including heart valves and stents

UNIVERSITY OF BATH

A new way of using 3D printing to create infection-fighting materials for use as medical implants has been revealed in a new research paper, published today.

Engineers at the University of Bath, working with colleagues at the University of Ulster, have for the first time successfully created a new kind of ferroelectric composite material with antimicrobial properties using a novel multi-material 3D printing process.

They say the use of electrically responsive ferroelectric materials gives the implants the infection-fighting properties, making them ideal for biomedical applications, such as heart valves, stents, and bone implants reducing the risk of infection for patients.

Reducing risk

While commonplace, all biomedical implants pose some level of risk as materials can carry surface bio-contaminants that can lead to infection. Reducing this risk could be beneficial both to patients in the form of improved outcomes, and to healthcare providers thanks to reduced costs incurred by ongoing treatment.

The team has previously used this 3D printing technique for the fabrication of three-dimensional scaffolds for bone tissue engineering.

Dr Hamideh Khanbareh, a lecturer in materials and structures in Bath’s Department of Mechanical Engineering, is lead author of the research. She says that the development has the scope for wide-ranging applications.

She says: “Biomedical implants that can fight infection or dangerous bacteria such as E. coli could present significant benefits to patients and to healthcare providers.

“Our research indicates that the ferroelectric composite materials we have created have a great potential as antimicrobial materials and surfaces. This is a potentially game-changing development that we would be keen to develop further through collaboration with medical researchers or healthcare providers.”

Infection-busting properties

The innovation comes thanks to ferroelectricity, a characteristic of certain polar materials that generate electrical surface charge in response to a change in mechanical energy or temperature. In ferroelectric films and implants, this electrical charge leads to the formation of free radicals known as reactive oxygen species (ROS), which selectively eradicate bacteria. This comes about through the micro-electrolysis of water molecules on a surface of polarised ferroelectric composite material.

The composite material used to harness this phenomenon is made by embedding ferroelectric barium calcium zirconate titanate (BCZT) micro-particles in polycaprolactone (PCL) a biodegradable polymer widely used in biomedical applications. The mixture of the ferroelectric particles and polymer is then fed into a 3D bioprinter to create a specific porous ‘scaffold’ shape designed to have a high surface area to promote ROS formation.

Testing showed that even when contaminated with high concentrations of aggressive E. coli bacteria, the composite can completely eradicate the bacteria cells without external intervention, killing 70% within just 15 minutes.

The research paper, Additively Manufactured Ferroelectric Particulate Composites for Antimicrobial Applications is published in Advanced Materials Technologies today (6 April 2023).

An image created by the research team to illustrate the research has been shortlisted as a finalist in the Science as Art competition at the Materials Research Society 2023 Spring Meeting & Exhibit.

ENDS

For more information contact Chris Melvin in the University of Bath press office on 01225 383941 / 07976 828268 or press@bath.ac.uk

About Bath

The University of Bath is one of the UK's leading universities for high-impact research with a reputation for excellence in education, student experience and graduate prospects. 

Acclaimed as the ‘University of the Year’ in The Times and The Sunday Times Good University Guide 2023, we are ranked 8th in the Complete University Guide 2023 and 7th in the Guardian University Guide 2023. Bath is rated in the world’s top 10 universities for sport in the QS World University Ranking by Subject 2023. 

For graduate employability, Bath is in the world’s top 100 universities according to the QS World University Rankings 2022. In the National Student Survey 2022, our overall student satisfaction was rated 10% above the national average and ranked in the UK’s top 3: https://www.bath.ac.uk/corporate-information/rankings-and-reputation/ 

Research from Bath is also helping to change the world for the better. Across the University’s three Faculties and School of Management, our research is making an impact in society, leading to low-carbon living, positive digital futures, and improved health and wellbeing. Find out all about ‘Research with Impact’: https://www.bath.ac.uk/campaigns/research-with-impact/

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JOURNAL

Advanced Materials Technologies

DOI

10.1002/admt.202202127 

METHOD OF RESEARCH

Experimental study

ARTICLE TITLE

Additively Manufactured Ferroelectric Particulate Composites for Antimicrobial Applications

New study reveals design clues for silver-based superatomic molecules

Researchers from Japan explore the key factors responsible for the synthesis of materials composed of silver-based superatoms

Peer-Reviewed Publication

TOKYO UNIVERSITY OF SCIENCE

 

IMAGE: THE FORMATION OF STABLE AG-BASED NANOCLUSTERS REQUIRE: (A) A BRIDGING HALOGEN THAT CAN MAINTAIN A MODERATE DISTANCE BETWEEN THE TWO AG13−XMX STRUCTURES, (B) A METAL ATOM FOR A STABLE ICOSAHEDRAL CORE AND (C) A COMBINATION OF HETEROATOMS AND BRIDGING HALOGENS THAT RESULTS IN 16 VALENCE ELECTRONS. view more 

CREDIT: YUICHI NEGISHI FROM TUS, JAPAN

In the past few decades, metal nanoclusters composed of noble metal elements such as gold (Au) and silver (Ag) have gained attention as superatoms for the synthesis of materials with unique properties and potential new applications. These superatoms (also known as “artificial atoms”) typically consist of a cluster of a few to several hundred atoms and exhibit properties that are significantly different from their bulk, conventional counterparts. However, much like real atoms, the stability of these superatoms is determined by the formation of a closed-shell electron structure.

Ag-based superatoms are known for their superior properties and functions, including photoluminescence and selective catalytic activity, compared to those of Au-based superatoms. However, most of the research in this field has been primarily focused on Au-based superatomic molecules.

To overcome this research gap, researchers from Japan studied the formation of superatomic molecules composed of Ag and evaluated the factors involved in this formation. This study was led by Professor Yuichi Negishi from Tokyo University of Science (TUS) with contributions from Dr. Sakiat Hossain from TUS, and Professor Tetsuya Taketsugu and Assistant Professor Takeshi Iwasa from Hokkaido University, and was published in the journal Communications Chemistry on 28 March 2023.

Speaking of the motivation behind studying Ag-based superatoms, Prof. Negishi says, “So far, we humans have created a variety of useful materials from the elements available to us on earth. However, looking at a future with complex energy and environmental issues, the development of materials with new properties and functions is desired.”

To this end, the researchers synthesized two di-superatomic molecules with bromine (Br) as the bridging ligand: ([Ag23Pt2(PPh3)10Br7]0 and [Ag23Pd2(PPh3)10Br7]0 (PPh3 = Triphenylphosphine). The former consisted of two icosahedral Ag12Pt superatoms connected by vertex sharing with platinum atoms (Pt) occupying the central position in each superatom. In contrast, the other superatomic molecule consisted of two icosahedral Ag12Pd structures with palladium (Pd) as the central atom.

The geometric/electronic structure and stability of these two nanoclusters was then analyzed and compared with [Ag23Pt2(PPh3)10Cl7]0 (1) and [Ag23Pd2(PPh3)10Cl7]0 (2) – two nanoclusters with geometrical similarity to the synthesized nanoclusters, consisting of chlorine (Cl) as the bridging atom.

On examining the geometric structures of the four nanoclusters, the researchers observed a twist between the two icosahedral structures containing Br as the bridging ligand. The researchers suggest that this twist stabilizes the nanocluster by shortening the distance between the two icosahedral structures.

Additionally, the larger Br atom was found to introduce steric hindrance in the molecule, causing both the PPh3 molecule to be positioned further from the long axis of the metal nanocluster and, a change in the bond length of the Ag-P and Ag-Ag bonds. These findings indicate that although the type of bridging halogen slightly affects the geometric structures of the metal nanoclusters, it does not hinder their formation.

“The type of bridging halogen appears to have little effect on whether superatomic molecules can be formed or not, as long as the bridging halogen is large enough to maintain a moderate distance between the two Ag12M structures,” explains Prof. Negishi.

However, the stability of the nanocluster was largely dependent on the number of bridging halogens attached to it. Like atoms, stable metallic nanoclusters require a filled valence shell. In the case of the prepared nanoclusters — which had a total of 16 valence electrons — the researchers were only able to attach a maximum of five bridging halogens to maintain the metal nanocluster in a stable neutral or cationic state.

The presence of Pd and Pt central atoms was found to be due to the formation of metallic nanoclusters. Substituting the central atom of Ag13 with Pt or Pd led to an increase in the average binding energy within the nanoclusters, making it favorable for the formation of superatomic molecules.

Overall, the researchers identified three key requirements for the formation and isolation of superatomic molecules consisting of two Ag13−xMx structures connected by vertex sharing. These include the presence of a bridging halogen that can maintain an optimal distance between the two structures, a combination of heteroatoms and bridging halogens that results in 16 valence electrons, and the formation of an icosahedral core that is stronger than Ag13.

In the words of Prof. Negishi, “These findings offer clear design guidelines for the creation of molecular devices with various properties and functions, and can potentially contribute to resolving pressing concerns regarding clean energy and the environment.”

 

***

 

Reference

DOI: https://doi.org/10.1038/s42004-023-00854-0

Authors: Sayuri Miyajima1, Sakiat Hossain2, Ayaka Ikeda1, Taiga Kosaka1, Tokuhisa Kawawaki1,2, Yoshiki Niihori2, Takeshi Iwasa3,4, Tetsuya Taketsugu3,4, and Yuichi Negishi1,2

Affiliations:        

1 Department of Applied Chemistry, Faculty of Science, Tokyo University of Science

2 Research Institute for Science & Technology, Tokyo University of Science

3 Department of Chemistry, Faculty of Science, Hokkaido University

4 WPI-ICReDD, Hokkaido University

 

Funding information

This study was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (grant numbers 20H02698 and 20H02552), Scientific Research on Innovative Areas “Innovations for Light-Energy Conversion” (grant numbers 18H05178 and 20H05115), Scientific Research on Innovative Areas “Hydrogenomics” (grant number 21H00027), and Scientific Research on Innovative Areas “Aquatic Functional Materials” (grant numbers and 22H04562). Funding provided by the Yazaki Memorial Foundation for Science and Technology, the Ogasawara Foundation for the Promotion of Science and Engineering, and TEPCO Memorial Foundation, the Japan Science Society, the Takahashi Industrial and Economic Research Foundation, and the Kubota Corporation is also gratefully acknowledged.

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JOURNAL

Communications Chemistry

DOI

10.1038/s42004-023-00854-0 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Key factors for connecting silver-based icosahedral superatoms by vertex sharing

A closer look at how environment influences physical activity

Public health researchers look at how science has examined the influence of social and built environments on people’s physical activity levels

Peer-Reviewed Publication

TEXAS A&M UNIVERSITY

Regular physical activity is one of the most effective ways to promote health and well-being and reduce chronic disease risk. However, many Americans fall short of the amount of regular physical activity needed to reap these benefits. Many studies have investigated the ways that the built environment and social factors influence physical activity, but a greater understanding of how physical and social factors interact and affect physical activity levels is crucial for addressing this activity shortfall, especially as communities recover from the COVID-19 pandemic and have relaxed physical distancing measures.

A new study published in the Journal of Physical Activity and Health reviews existing literature on the influences the built environment and social factors have on physical activity to find patterns between studies and avenues for future research. Tyler Prochnow, PhD, assistant professor at the Texas A&M University School of Public Health, and colleagues from the School of Public Health, conducted a systematic review of literature on physical activity to see how influences of the social and built environments have been studied together, the ways the social and built environments affect each other to impact physical activity and which factors affect physical activity levels.

"The overlap between the social and physical environments are so critical for health behaviors like physical activity,” said Prochnow. “We need to do a better job of jointly measuring these environments and promoting policy, system, and environment changes to optimize these influences."

The researchers searched several scientific literature databases using search terms related to physical activity, the built environment, social factors and social network analysis and interaction. To be included in the review, articles needed to include measurements of physical activity, data on the built environment and information on social factors. Articles also had to do some sort of analysis on interactions between the built and social environments and physical activity. The researchers initially identified more than 4,000 articles and narrowed down the selection to 87 articles that met their criteria.

The built and social environments have been shown to influence physical activity. The built environment covers physical aspects of communities such as walkability, perceived safety and access to parks and recreation facilities. The social environment includes relationships, interpersonal connections, peer group interactions, social norms, and other behavioral influences.

The articles in the review used many different methods for measuring social and built environments and physical activity levels. These differences may make comparing studies challenging. In addition, some of the studies the researchers analyzed used methods that have not been fully validated, which could introduce bias. The studies also mostly covered a single point in time, limiting their ability to fully show causal relationships between environmental factors and physical activity over time. Only a handful of studies were experimental or longitudinal, that is, studies that followed a population over a longer period. In addition, the researchers noted that more frequent or even real-time measurements are needed to clarify how the social and built environments and physical activity interact.

The researchers also identified a gap in research that compares the effects of different factors across communities and how the social and built environment may influence health disparities between different demographic groups. Having a greater understanding of these interactions is crucial for reducing health disparities.

The results of this review highlight a need for more studies using experimental or longitudinal designs. They also identified the importance of real-time measurements and validated measures of social and built environment factors. Additionally, an understanding of how social and built environment factors influence each other and physical activity levels across communities is vital. This is especially the case as communities recover from the COVID-19 pandemic because physical distancing measures could have influenced social and environmental interactions.

Understanding how the built environment and social interactions affect physical activity levels is a key part of helping people get the recommended amount of physical activity. Reducing obstacles to activity can make it easier for more people to get and stay active and lead healthier lives.

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JOURNAL

Journal of Physical Activity and Health

DOI

10.1123/jpah.2022-0403 

ARTICLE TITLE

Bridging the Built and Social Environments: A Systematic Review of Studies Investigating Influences on Physical Activity

Lifesaving drug for severe bleeding after childbirth could be made accessible for all, study suggests

Peer-Reviewed Publication

LONDON SCHOOL OF HYGIENE & TROPICAL MEDICINE

Intramuscular administration of tranexamic acid (TXA), a drug used to target severe bleeding after childbirth, is safe and quickly reaches therapeutic concentrations in pregnant women, according to a study involving researchers from the London School of Hygiene & Tropical Medicine (LSHTM).

The findings, from the Woman-PharmacoTXA Phase 2 trial, highlight that intramuscular injection may be a potential alternative to current intravenous approaches, which are often unsuitable in home births or rural care settings.

Oral TXA was also well-tolerated, however, on average, took around one hour to reach therapeutic blood concentrations, meaning it could be unsuitable for emergency treatment.

The results are published in the British Journal of Obstetrics and Gynaecology.

Severe bleeding after childbirth, or postpartum haemorrhage (PPH), is one of the leading causes of maternal death worldwide, with most of the 70,000 yearly deaths occurring in low-and middle-income countries (LMICs).

Results from the earlier WOMAN trial, led by researchers from LSHTM with collaboration from 21 countries, provided crucial evidence for the life-saving potential of repurposing TXA for treating PPH.

Originally used in surgery and later in trauma, TXA works by inhibiting the breakdown of blood clots.

Although intravenous administration of TXA is the first port-of-call for treatment, many births in LMICs take place at home, with access to healthcare settings often limited. Subsequently, focus has shifted towards finding alternative administration routes. 

In this trial, an international research team, including from LSHTM, recruited over 120 women aged 18 or older who were due to give birth by caesarean section at two hospitals in Pakistan and one in Zambia between December 2020 and June 2021. All women had one or more risk factors for postpartum haemorrhage.

The study is the first trial testing several different routes of administration in women giving birth and notably the first to test the intramuscular route, specifically in pregnant women.

Overall, intramuscular and oral TXA were well tolerated, with no serious side effects for mothers or newborns. Target concentrations of TXA in maternal blood were achieved for both routes, although for oral TXA this took an hour – a characteristic that could prevent its use in emergency treatment. Intramuscular TXA, however, reached therapeutic concentrations within ten minutes of injection, which was maintained for over four hours. 

The authors conclude that these findings provide enough evidence to conduct comparative Phase 3 clinical trials (I’M WOMAN) beginning in August this year. These will aim to determine if intramuscular administration is as effective as intravenous routes in reducing postpartum bleeding.

Professor Haleema Shakur-Still, co-author and Professor of Global Health Clinical Trials at LSHTM said: “In many LMICs, women do not give births in healthcare facilities, so if TXA can be given just as successfully intramuscularly as via intravenous injection, this could be of huge significance to the thousands of women who die every year from PPH.”

Professor Rizwana Chaudhri, co-author based at Shifa Tameer-e-Millat University, Islamabad, Pakistan said: “The intramuscular route will be very helpful in Pakistan. With some patients who are experiencing a PPH, it is difficult to get an intravenous line established, so anything that can reduce PPH will be useful. In some cases, it will be the first and last choice.”

Dr Mwansa Ketty Lubeya, co-author based at The University of Zambia-School of Medicine, Women and Newborn Hospital-UTH said: “In Zambia, we are still struggling with access to TXA. Even when it is available, there should be options in terms of administration. There is no point in having TXA when canulation is not an option. We are excited to have the intramuscular option and be able to use it far and wide.”

Dr Ian Roberts, co-author and Professor of Epidemiology at LSHTM said: “We have good reason to believe the intramuscular route will be as effective as the intravenous route to reduce postpartum bleeding. In August, we are starting a large global trial to prove this in the hope that this will change WHO guidelines. We want to make this lifesaving treatment available to all women wherever they give birth.” 

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JOURNAL

British Journal of Obstetrics and Gynaecology

DOI

10.1111/1471-0528.17455 

METHOD OF RESEARCH

Randomized controlled/clinical trial

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Alternative routes for tranexamic acid treatment in obstetric bleeding (WOMAN-PharmacoTXA trial): a randomised trial and pharmacological study in caesarean section births

Respiratory virus plagues SA but new vaccine for pregnant moms saves babies

Peer-Reviewed Publication

UNIVERSITY OF THE WITWATERSRAND

This is what the MATISSE study conducted in 18 countries including South Africa aimed to find out.

The Maternal Immunization Study for Safety and Efficacy (MATISSE) phase 3 trial evaluated the efficacy and safety of maternal RSVpreF vaccination in preventing RSV-associated lower respiratory tract illness in infants. 

Respiratory syncytial virus (RSV) is the most common cause of hospitalisation in children under five years of age, and even more so in those younger than six months.

Researchers at the Wits Vaccines and Infectious Diseases Analytics Research Unit (Wits VIDA) at the University of the Witwatersrand, Johannesburg, led the MATISSE trial in South Africa.

The researchers wanted to find out if administering Pfizer’s Bivalent Prefusion F Vaccine in pregnancy could reduce the burden of RSV-associated lower respiratory tract illness in new-borns and infants and, if so, how well, and for how long?

In this trial, as part of a multi-centred study, Wits VIDA report that vaccination of pregnant women with the RSV vaccine is safe, and reduces the risk of severe RSV associated lower respiratory tract infection by 82% in infants aged through to six months old.

The findings were published in the New England Journal of Medicine (NEJM) on 5 April 2023.

“This study adds to the portfolio of research on vaccination of pregnant women to protect the mother, foetus and new-born,” says study author and Director of Wits VIDA, Professor Shabir Madhi. “The release of these study findings, in which South African scientists played a prominent role, comes at a time when RSV is back with a vengeance in SA, with paediatric wards being filled with children in whom illness can now be prevented with this new RSV vaccine.”

The urgency to immunise against RSV

Lower respiratory tract infections (LRTI) are the most common cause of hospitalisation and death in children 1-59 months of age, particularly in low- and middle-income countries (LMICs).

RSV is the most common cause of LRTI hospitalisation in children, occurring in some 30-80% of cases.

Approximately two-thirds of children will be infected at least once by RSV in the first two years of life, a third of whom will develop LRTI.

In 2019, it was estimated that there were 101 400 RSV-attributable deaths, 99% of which occurred in LMICs and 50% of which were in children less than 6 months of age.

Death from RSV is likely to be underestimated in low-income settings. There has been no change in the burden of RSV over the past two decades.

RSV-LTRI immunisation a global priority and a LMIC urgency

Vaccines to prevent RSV-LRTI are considered a priority by the World Health Organization.

There is currently no antiviral treatment for children with RSV infection, and management of RSV-LRTI is symptom based.

Palivizumab, a costly monoclonal antibody, is the only licensed effective strategy to reduce the risk of RSV-LRTI hospitalisation in South Africa.

The MATISSE study shows that the RSV prefusion F protein-based vaccine (RSVpreF) administered during the late second or third trimester of pregnancy may protect infants from severe RSV illness during the first few months of life – this would be particularly important in low- and middle-income countries, where the burden of RSV-associated lower respiratory tract illness is highest.

About the MATISSE Clinical Trial

Funded by Pfizer; MATISSE ClinicalTrials.gov number, NCT04424316. DOI: 10.1056/NEJMoa2216480

About Wits VIDA

Established in 1997 as the Pneumococcal Diseases Research Unit and then the Respiratory and Meningeal Pathogens Research Unit, it rebranded in 2019 to the Vaccines and Infectious Diseases Analytics Research Unit (Wits VIDA). Research focuses on clinical and molecular epidemiology of vaccine preventable disease; clinical development and evaluation of vaccines; the study of the immunology of vaccines including in people living with HIV; and basic science research aimed at discovering vaccine candidates. In 2017, Wits VIDA established a health and demographic surveillance platform (HDSS) to understand the context in which infections occur and how disease trends affect population dynamics, both in children and pregnant women. The HDSS platform was integral to understanding Covid-19 epidemiology, its effects, and excess mortality across age groups. An established social-behavioural science stream at Wits VIDA is currently exploring motivations and barriers to vaccination and behaviours impacting maternal and infant health, amongst others.

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JOURNAL

New England Journal of Medicine

DOI

10.1056/NEJMoa2216480 

METHOD OF RESEARCH

Randomized controlled/clinical trial

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Bivalent Prefusion F Vaccine in Pregnancy to Prevent RSV Illness in Infants

Vaccination during pregnancy could prevent RSV illness in infants

Clinical study shows vaccine to be effective and well tolerated

Peer-Reviewed Publication

CHARITÉ - UNIVERSITÄTSMEDIZIN BERLIN

It is estimated that about 50 to 70 percent of children in Germany contract RSV in the first year of life, and nearly every child will have been infected at least once before reaching two years of age. Illness generally starts with mild cold-like symptoms before progressing to the lower respiratory tract and lungs. The disease can cause acute breathing problems and shortness of breath. Around the world, some 100,000 children under the age of five years died as a result of RSV infection in 2019, about 97 percent of them in low- and middle-income countries.

“Previously, only symptomatic treatment was available for RSV. In severe cases, supplemental oxygen is vital, but in poorer countries, it is often not administered fast enough or to an adequate extent,” says Dr. Beate Kampmann, head of the Institute of International Health at Charité and Einstein Professor for Global Health. “This means we urgently need an vaccine to provide effective protection against RSV severe disease for the most vulnerable group, namely children under six months old.”

One promising option is vaccination during pregnancy, which is already recommended for diseases such as the flu, whooping cough, and COVID-19. Expectant mothers generate antibodies after receiving the vaccine and then pass them along to the unborn child through the placenta. The baby is born with effective immune defenses that persist through the first few months of life.

Extensive vaccination study in 18 countries

Now, a pharmaceutical company has developed this kind of vaccine to be administered during pregnancy, targeting RSV. The new vaccine, called RSV-preF, was the subject of an extensive international study performed in 18 countries between 2020 and 2022, which investigated its tolerability and efficacy. Kampmann played an instrumental role in the study as part of her longstanding research work within the vaccines and immunity theme with the Medical Research Council (MRC) Unit The Gambia, part of the London School of Hygiene and Tropical Medicine (LSHTM).

In the phase 3 trial that has now been published, the vaccine was administered to 3,682 randomly selected participants during the second or third trimester of pregnancy as a shot in the upper arm. A similarly sized comparison group received a placebo shot containing no vaccine. Neither the participants nor the heads of the study knew at any time up to the conclusion of the trial who had received the vaccine and who had been given the placebo. That makes it a placebo-controlled randomized double-blind trial, which is aligned with the very highest standards of quality.

The children were examined regularly and upon any signs of respiratory illness for one to two years after birth. They were also tested for RSV, and the severity of illness was assessed according to a predefined scale used for the study.

Approval for RSV vaccine sought

“The results of the vaccine trial are extremely positive,” Kampmann says. “In over 80 percent of children, maternal immunization during pregnancy prevented severe RSV disease in the first three months of life, and over two-thirds were still protected at six months of age. The vaccine was also very well tolerated.” The maker of the vaccine has applied to the European and U.S. drug authorities for approval. Results of the review are expected later this year.

Nearly half of the study’s participants came from the United States, while 30 percent live in low- or middle-income countries. Kampmann’s team recruited about 200 participants in Gambia, for example. “We were able to use the platform for vaccine trials involving pregnant women that we had already established in Gambia for the RSV vaccine study as well,” she says. Kampmann, a proven expert in childhood infectious disease, has been working in the West African country for more than a decade now. Her activities have included initiating a program for immunization during pregnancy to combat whooping cough (pertussis) during childhood. The goal is to prevent these kinds of diseases and lower infant mortality rates.

“It’s important to perform vaccine trials in the countries where the vaccines are to be used later on,” Kampmann says. “Especially in socioeconomically disadvantaged countries, people often suffer from chronic gastrointestinal conditions due to poor hygiene conditions. That can lower the effectiveness of vaccination, as in the case of the rotavirus vaccine. And there are comorbidities such as malaria and HIV that impair the transfer of antibodies through the placenta. All these factors affect how well a vaccine works in the end.” When it comes to national vaccination bodies, it is also important for a vaccine to have proven effective within that region so it can be recommended later on.

“The RSV vaccine was tolerated extremely well overall by the participants, and its effectiveness in preventing severe RSV disease in infants was persuasive. We’d like to thank all the women who participated in the study, and we hope the vaccine will be in use soon, saving many young lives.” That applies to children in Gambia and around the world, since the 2022/23 season that just concluded highlighted the consequences of RSV infections. In Germany alone, intensive care admissions among infants and toddlers increased by as much as 350 percent, according to the Robert Koch Institute, Germany’s federal public health agency. The situation pushed healthcare systems to their limits at times.

*Kampmann B et al. Bivalent Prefusion F Vaccine in Pregnancy to Prevent RSV Illness in Infants. NEJM, 2023 Apr 05. doi: 10.1056/NEJMoa2216480

About the study
The phase 3 clinical trial (Maternal Immunization Study for Safety and Efficacy – MATISSE) was sponsored and funded by the pharmaceutical company Pfizer. Kampmann and her team did not receive any personal fees for the study.

Links
Original publication
Institute of International Health
London School of Hygiene and Tropical Medicine (LSHTM)
IMPRINT – IMmunising PRegnant women and INfants network
MRC The Gambia

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JOURNAL

New England Journal of Medicine

DOI

10.1056/NEJMoa2216480 

METHOD OF RESEARCH

Randomized controlled/clinical trial

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Bivalent Prefusion F Vaccine in Pregnancy to Prevent RSV Illness in Infants

Limit added sugar to six teaspoons a day to improve health, urge experts

Evidence review finds harmful links between excess sugar intake and 45 outcomes including diabetes, depression, obesity and heart disease

Peer-Reviewed Publication

BMJ

Experts recommend reducing consumption of added (“free”) sugars to around six teaspoons a day and limiting sugar-sweetened drinks to less than one serving a week after a comprehensive evidence review published by The BMJ today.  

They found significant harmful associations between sugar consumption and 45 outcomes, including asthma, diabetes, obesity, heart disease, depression, some cancers and death. 

It’s widely known that excessive sugar intake can have negative effects on health and this has prompted the World Health Organization (WHO) and others to suggest reducing consumption of free or added sugars to less than 10% of total daily energy intake.

But before developing detailed policies for sugar restriction, the quality of existing evidence needs to be comprehensively evaluated. 

Researchers based in China and the US therefore carried out an umbrella review to assess the quality of evidence, potential biases, and validity of all available studies on dietary sugar consumption and health outcomes.

Umbrella reviews synthesise previous meta-analyses and provide a high-level summary of research on a particular topic.

The review included 73 meta-analyses (67 of observational studies and six of randomised controlled trials) from 8,601 articles covering 83 health outcomes in adults and children.

The researchers assessed the methodological quality of the included articles and graded the evidence for each outcome as high, moderate, low, or very low quality to draw conclusions.

Significant harmful associations were found between dietary sugar consumption and 18 endocrine or metabolic outcomes including diabetes, gout and obesity; 10 cardiovascular outcomes including high blood pressure, heart attack and stroke; seven cancer outcomes including breast, prostate and pancreatic cancer; and 10 other outcomes including asthma, tooth decay, depression and death.

Moderate quality evidence suggested that sugar sweetened beverage consumption was significantly associated with increased body weight for highest versus lowest consumption, while any versus no added sugar consumption was associated with increased liver and muscle fat accumulation.

Low quality evidence indicated that each one serving per week increment of sugar sweetened beverage consumption was associated with a 4% higher risk of gout, and each 250 mL/day increment of sugar sweetened beverage consumption was associated with a 17% and 4% higher risk of coronary heart disease and death, respectively.

Low quality evidence also suggested that every 25 g/day increment of fructose intake was associated with a 22% increased risk of pancreatic cancer. 

In general, no reliable evidence showed beneficial associations between dietary sugar consumption and any health outcomes, apart from glioma brain tumours, total cholesterol, type 2 diabetes and cardiovascular disease mortality. However, the researchers say these favourable associations are not supported by strong evidence, and these results should be interpreted with caution. 

The researchers acknowledge that existing evidence is mostly observational and of low quality, and stress that evidence for an association between dietary sugar consumption and cancer remains limited but warrants further research. 

Nevertheless, they say these findings, combined with WHO, World Cancer Research Fund and American Institute for Cancer Research guidance, suggest reducing the consumption of free sugars or added sugars to below 25 g/day (approximately six teaspoons a day) and limiting the consumption of sugar sweetened beverages to less than one serving a week (approximately 200-355 mL/week).

To change sugar consumption patterns, especially for children and adolescents, a combination of widespread public health education and policies worldwide is also urgently needed, they add.
 

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JOURNAL

The BMJ

DOI

10.1136/bmj-2022-071609 

METHOD OF RESEARCH

Systematic review

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Dietary sugar consumption and health: umbrella review

ARTICLE PUBLICATION DATE

5-Apr-2023

COI STATEMENT

All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest/ and declare: support from the National Natural Science Foundation of China and Program from the Department of Science and Technology of Sichuan Province for the submitted work; no financial relationship with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.