̽��ֱ�� of Cambridge - Gates Cambridge Trust

Prioritise vaccine boosters for vulnerable immunocompromised patients, say scientists

cjb250 — Wed, 12 Feb 2025 19:00:46 +0000

̽��ֱ��findings, published today in Science Advances, suggest that such individuals will need regular vaccine boosters to protect them and reduce the risk of infections that could be severe and also lead to new ‘variants of concern’ emerging.

Almost 16 million people worldwide are estimated to have died from Covid-19 during 2020 and 2021, though nearly 20 million deaths are thought to have been prevented as a result of the rapid rollout of vaccines against SARS-CoV-2, the virus that caused the pandemic.

During the pandemic, researchers discovered that immunocompromised individuals had difficulty clearing the virus, even when vaccinated. These are people whose immune systems are not functioning correctly, either as a direct result of disease or because they are on medication to dampen down their immune systems, for example to prevent organ transplant rejection. This meant that their infections lasted longer, giving the virus more opportunities to mutate.

Research from early in the pandemic showed that chronic infections can give rise to variants of concern that can then cause new waves of infection in the wider population.

When an individual is vaccinated, their immune systems produce antibodies that recognise and launch an attack on the virus. Such a process is known as seroconversion. Additional ‘booster’ vaccinations increase seroconversion and hence the likelihood of clearing infection.

However, although most immunocompromised individuals will have received three or more doses of the Covid-19 vaccine, they still account for more than a fifth of hospitalisations, admissions to intensive care units, and overall deaths associated with the disease.

To see why this is the case, scientists at the Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID) at the ̽��ֱ�� of Cambridge examined immunocompromised individuals who had been vaccinated against Covid-19. These patients, recruited from Cambridge ̽��ֱ�� Hospitals NHS Foundation Trust, were living with vasculitis, a group of disorders that cause inflammation of blood vessels. Data from this group was compared against individuals who were not immunocompromised.

Treatments for vasculitis rely on immunosuppressant medicines. These include drugs such as rituximab, which depletes the number of B-cells in the body – but B-cells are the immune cells responsible for producing antibodies. As such, these individuals are a severely at-risk population.

When the researchers analysed bloods samples from the vasculitis patients, they found that even though vaccination induced seroconversion, this in itself was not always sufficient to neutralise the virus. Every immunocompromised individual required at least three doses of the vaccine to protect them across a range of variants up to and include Omicron (the variant that appeared towards the end of 2021 and caused a new wave of infections). In some cases, even four vaccinations were not sufficient to adequately protect them.

Kimia Kamelian, a Gates Cambridge Scholar at CITIID and St Edmund's College, Cambridge, said: “We know that immunocompromised individuals are particularly vulnerable to diseases such as Covid-19 because their immune systems struggle to clear infections. Vaccinations offer some protection, but our study shows that only repeated vaccinations – often four or more – offer the necessary protection.”

Professor Ravi Gupta, also from CITIID and a Fellow at Homerton College, Cambridge, added: “This of course has implications for the individual, who is more likely to have prolonged infection and a much greater risk of severe infection, but it also gives the virus multiple opportunities to mutate.

“We know from our previous work that at least some of the variants of concern probably emerged during chronic infections. That’s why these individuals must be given priority for updated vaccines against new variants.”

̽��ֱ��research was funded by Wellcome, Gates Cambridge, Addenbrooke’s Charitable Trust and Vasculitis UK, with additional support by the National Institute for Health and Care Research Cambridge Biomedical Research Centre.

Reference
Kamelian, K et al. Humoral responses to SARS-CoV-2 vaccine in vasculitis-related immune suppression. Sci Adv; 12 Feb 2025; DOI: 10.1126/sciadv.adq3342

Vaccinations alone may not be enough to protect people with compromised immune systems from infection, even if the vaccine has generated the production of antibodies, new research from the ̽��ֱ�� of Cambridge has shown.

We know that immunocompromised individuals are particularly vulnerable to diseases such as Covid-19 because their immune systems struggle to clear infections

Kimia Kamelian

NoSystem images

Vaccination of an senior male

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Making an impact: Gates Cambridge turns 25

cjb250 — Mon, 06 Jan 2025 09:42:36 +0000

What unites a wildlife cameraman, a quantum physicist and the co-founder of a solar energy business? For Gates Cambridge Scholars, it's the desire to improve the lives of others.

Gender inequality ingrained in global climate negotiations, say researchers

cjb250 — Mon, 11 Nov 2024 08:52:16 +0000

In an article published today in Lancet Planetary Health, a team of researchers – including several from the ̽��ֱ�� of Cambridge – argue that much more needs to be done to mitigate the impacts of climate change on women, girls and gender-diverse individuals.

Focusing specifically on the intersection between climate change, gender, and human health, the researchers call on countries to work harder to ensure there is gender equity within their delegations to climate conferences and to ensure climate strategies identify gender-specific risks and vulnerabilities and address their root causes.

As the world prepares for COP29, concerns about gender representation and equality have reignited following the initial appointment of 28 men and no women to the COP29 organising committee in January 2024.

̽��ֱ��effects of climate change – from heavy rains, rising temperatures, storms and floods through to sea level rises and droughts – exacerbate systemic inequalities and disproportionately affect marginalised populations, particularly those living in low-income areas.

While the specific situation may be different depending on where people live or their social background (like their class, race, ability, sexuality, age, or location), women, girls, and gender minorities are often at greater risk from the impacts of climate change. For example, in many countries, women are less likely to own land and resources to protect them in post-disaster situations, and have less control over income and less access to information, resulting in increased vulnerability to acute and long-term climate change impacts.

They are also particularly at risk from climate-related threats to their health, say the researchers. For example, studies have linked high temperatures to adverse birth outcomes such as spontaneous preterm births, pre-eclampsia and birth defects. Extreme events, which are expected to become more likely and intense due to climate change, also take a severe toll on women's social, physical, and mental well-being. Numerous studies highlight that gender-based violence is reported to increase during or after extreme events, often due to factors related to economic instability, food insecurity, disrupted infrastructure and mental stress.

Dr Kim Robin van Daalen, a former Gates Cambridge Scholar at the ̽��ֱ�� of Cambridge, and researcher at the Barcelona Supercomputing Center (BSC), said: “Given how disproportionately climate change affects women, girls and gender minorities – a situation that is only likely to get worse – we need to ensure that their voices are heard and meaningfully included in discussions of how we respond to this urgent climate crisis. This is not currently happening at anywhere near the level it needs to.”

̽��ֱ��team summarised the inclusion of gender, health and their intersection in key decisions and initiatives under the United Nations Framework Convention on Climate Change (UNFCCC), and analysed gender representation among representatives of Party and Observer State delegations at COPs between 1995-2023. Progress has been slow, they say.

They highlight how previous scholars have consistently noted that emphasis remains mainly on achieving a gender ‘number-based balance’ in climate governance, over exploring gender-specific risks and vulnerabilities and addressing their root causes. They also discuss how there remains limited recognition of the role climate change has in worsening gendered impacts on health, including gender-based violence and the lack of safeguarding reproductive health in the face of climate change.

Although the situation is slowly improving, at COP28, almost three-quarters (73%) of Party delegations were still majority men, and only just over one in six (16%) showed gender parity (that is, 45-55% women). In fact, gender parity has only been achieved in the ‘Western European and Other’ UN grouping (which also includes North America, Australia and New Zealand). Based on current trends, several countries - particularly those in the Asia-Pacific and Africa regions - are expected to take at least a decade from COP28 before reaching gender parity in their delegations.

Dr Ramit Debnath, former Gates Cambridge Scholar and now an Assistant Professor at Cambridge, said: “ ̽��ֱ��urgency of climate action, as well as the slow understanding of climate, gender, and health connections, is cause for concern. Institutions like the UNFCCC must recognize these disparities, design appropriate methods to improve gender parity in climate governance, and keep these representation gaps from growing into societal and health injustices.”

Beyond ensuring that their voices are heard, more equitable inclusion of women has consistently been suggested to transform policymaking across political and social systems, including the generation of policies that better represent women’s interests. Previous recent analyses of 49 European countries revealed that greater women’s political representation correlates with reduced inequalities in self-reported health, lower geographical inequalities in infant mortality and fewer disability-adjusted life-years lost across genders.

Similar positive findings have been reported related to environmental policies, with women’s representation in national parliaments being associated with increased ratification of environmental treaties and more stringent climate change policies. For example, women legislators in the European parliament and US House of Representatives have been found to be more inclined to support environmental legislation than men.

Dr Ronita Bardhan, Associate Professor at the ̽��ֱ�� of Cambridge, said: "Achieving equitable gender representation in climate action is not just about fairness - it's a strategic necessity with significant co-benefits. We can shape climate policies and infrastructure that address a broader spectrum of societal needs, leading to more inclusive solutions enhancing public health, social equity, and environmental resilience."

While the researchers’ analyses focused on achieving gender balance, studies on women’s involvement in climate governance suggest that increased representation does not by itself always lead to meaningful policy changes. Even when formally included, women’s active participation in male-dominated institutions is often constrained by existing social and cultural norms, implicit biases and structural barriers.

Dr van Daalen added: “If we’re to meaningfully incorporate gender into climate policy and practice, we need to understand the risks and vulnerabilities that are gender-specific and look at how we can address them and their root causes at all phases of programme and policy development.

“But we also need to resist reducing women to a single, homogenous group, which risks deepening existing inequalities and overlooks opportunities to address the needs of all individuals. It is crucial to recognise the diversity of women and their embodiment of multiple, intersecting identities that shape their climate experiences as well as their mitigation and adaptation needs.”

̽��ֱ��team also highlights that gender-diverse people face unique health and climate-related risks due to their increased vulnerability, stigma, and discrimination. For example, during and after extreme events, transgender people in the United States report being threatened or prohibited access to shelters. Similarly, in the Philippines, Indonesia, and Samoa, gender-diverse individuals often face discrimination, mockery, and exclusion from evacuation centres or access to food. Yet, say the researchers, there are major gaps in knowledge about the health implications of climate change for such groups.

Find out how Cambridge's pioneering research in climate and nature is regenerating nature, rewiring energy, rethinking transport and redefining economics - forging a future for our planet.

Reference
Van Daalen, KR et al. Bridging the gender, climate, and health gap: the road to COP29. Lancet Planetary Health; 11 Nov 2024; DOI: 10.1016/S2542-5196(24)00270-5

Climate governance is dominated by men, yet the health impacts of the climate crisis often affect women, girls, and gender-diverse people disproportionately, argue researchers ahead of the upcoming 29th United Nations Climate Summit (COP29) in Azerbaijan.

Given how disproportionately climate change affects women, girls and gender minorities, we need to ensure that their voices are heard and meaningfully included in discussions of how we respond to this urgent climate crisis

Kim van Daalen

Hansel ohioma

Surviving the flood at Ahoada in Rivers state Nigeria

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Gates Cambridge: Class of 2024

mjg209 — Wed, 17 Apr 2024 08:00:00 +0000

This year’s Gates Cambridge cohort comprises 75 new scholars, studying areas from the impact of climate change on tropical biodiversity to how the circulation of conflict photographs shapes perception.

AI predicts healthiness of food menus

cjb250 — Fri, 08 Mar 2024 08:00:27 +0000

Cambridge researchers have used artificial intelligence to predict the healthiness of café, takeaway and restaurant menus at outlets across Britain and used this information to map which of its local authorities have the most and least healthy food environments.

AI system self-organises to develop features of brains of complex organisms

cjb250 — Mon, 20 Nov 2023 16:00:47 +0000

As neural systems such as the brain organise themselves and make connections, they have to balance competing demands. For example, energy and resources are needed to grow and sustain the network in physical space, while at the same time optimising the network for information processing. This trade-off shapes all brains within and across species, which may help explain why many brains converge on similar organisational solutions.

Jascha Achterberg, a Gates Scholar from the Medical Research Council Cognition and Brain Sciences Unit (MRC CBU) at the ̽��ֱ�� of Cambridge said: “Not only is the brain great at solving complex problems, it does so while using very little energy. In our new work we show that considering the brain’s problem solving abilities alongside its goal of spending as few resources as possible can help us understand why brains look like they do.”

Co-lead author Dr Danyal Akarca, also from the MRC CBU, added: “This stems from a broad principle, which is that biological systems commonly evolve to make the most of what energetic resources they have available to them. ̽��ֱ��solutions they come to are often very elegant and reflect the trade-offs between various forces imposed on them.”

In a study published today in Nature Machine Intelligence, Achterberg, Akarca and colleagues created an artificial system intended to model a very simplified version of the brain and applied physical constraints. They found that their system went on to develop certain key characteristics and tactics similar to those found in human brains.

Instead of real neurons, the system used computational nodes. Neurons and nodes are similar in function, in that each takes an input, transforms it, and produces an output, and a single node or neuron might connect to multiple others, all inputting information to be computed.

In their system, however, the researchers applied a ‘physical’ constraint on the system. Each node was given a specific location in a virtual space, and the further away two nodes were, the more difficult it was for them to communicate. This is similar to how neurons in the human brain are organised.

̽��ֱ��researchers gave the system a simple task to complete – in this case a simplified version of a maze navigation task typically given to animals such as rats and macaques when studying the brain, where it has to combine multiple pieces of information to decide on the shortest route to get to the end point.

One of the reasons the team chose this particular task is because to complete it, the system needs to maintain a number of elements – start location, end location and intermediate steps – and once it has learned to do the task reliably, it is possible to observe, at different moments in a trial, which nodes are important. For example, one particular cluster of nodes may encode the finish locations, while others encode the available routes, and it is possible to track which nodes are active at different stages of the task.

Initially, the system does not know how to complete the task and makes mistakes. But when it is given feedback it gradually learns to get better at the task. It learns by changing the strength of the connections between its nodes, similar to how the strength of connections between brain cells changes as we learn. ̽��ֱ��system then repeats the task over and over again, until eventually it learns to perform it correctly.

With their system, however, the physical constraint meant that the further away two nodes were, the more difficult it was to build a connection between the two nodes in response to the feedback. In the human brain, connections that span a large physical distance are expensive to form and maintain.

When the system was asked to perform the task under these constraints, it used some of the same tricks used by real human brains to solve the task. For example, to get around the constraints, the artificial systems started to develop hubs – highly connected nodes that act as conduits for passing information across the network.

More surprising, however, was that the response profiles of individual nodes themselves began to change: in other words, rather than having a system where each node codes for one particular property of the maze task, like the goal location or the next choice, nodes developed a flexible coding scheme. This means that at different moments in time nodes might be firing for a mix of the properties of the maze. For instance, the same node might be able to encode multiple locations of a maze, rather than needing specialised nodes for encoding specific locations. This is another feature seen in the brains of complex organisms.

Co-author Professor Duncan Astle, from Cambridge’s Department of Psychiatry, said: “This simple constraint – it’s harder to wire nodes that are far apart – forces artificial systems to produce some quite complicated characteristics. Interestingly, they are characteristics shared by biological systems like the human brain. I think that tells us something fundamental about why our brains are organised the way they are.”

Understanding the human brain

̽��ֱ��team are hopeful that their AI system could begin to shed light on how these constraints, shape differences between people’s brains, and contribute to differences seen in those that experience cognitive or mental health difficulties.

Co-author Professor John Duncan from the MRC CBU said: “These artificial brains give us a way to understand the rich and bewildering data we see when the activity of real neurons is recorded in real brains.”

Achterberg added: “Artificial ‘brains’ allow us to ask questions that it would be impossible to look at in an actual biological system. We can train the system to perform tasks and then play around experimentally with the constraints we impose, to see if it begins to look more like the brains of particular individuals.”

Implications for designing future AI systems

̽��ֱ��findings are likely to be of interest to the AI community, too, where they could allow for the development of more efficient systems, particularly in situations where there are likely to be physical constraints.

Dr Akarca said: “AI researchers are constantly trying to work out how to make complex, neural systems that can encode and perform in a flexible way that is efficient. To achieve this, we think that neurobiology will give us a lot of inspiration. For example, the overall wiring cost of the system we've created is much lower than you would find in a typical AI system.”

Many modern AI solutions involve using architectures that only superficially resemble a brain. ̽��ֱ��researchers say their works shows that the type of problem the AI is solving will influence which architecture is the most powerful to use.

Achterberg said: “If you want to build an artificially-intelligent system that solves similar problems to humans, then ultimately the system will end up looking much closer to an actual brain than systems running on large compute cluster that specialise in very different tasks to those carried out by humans. ̽��ֱ��architecture and structure we see in our artificial ‘brain’ is there because it is beneficial for handling the specific brain-like challenges it faces.”

This means that robots that have to process a large amount of constantly changing information with finite energetic resources could benefit from having brain structures not dissimilar to ours.

Achterberg added: “Brains of robots that are deployed in the real physical world are probably going to look more like our brains because they might face the same challenges as us. They need to constantly process new information coming in through their sensors while controlling their bodies to move through space towards a goal. Many systems will need to run all their computations with a limited supply of electric energy and so, to balance these energetic constraints with the amount of information it needs to process, it will probably need a brain structure similar to ours.”

̽��ֱ��research was funded by the Medical Research Council, Gates Cambridge, the James S McDonnell Foundation, Templeton World Charity Foundation and Google DeepMind.

Reference
Achterberg, J & Akarca, D et al. Spatially embedded recurrent neural networks reveal widespread links between structural and functional neuroscience findings. Nature Machine Intelligence; 20 Nov 2023; DOI: 10.1038/s42256-023-00748-9

Cambridge scientists have shown that placing physical constraints on an artificially-intelligent system – in much the same way that the human brain has to develop and operate within physical and biological constraints – allows it to develop features of the brains of complex organisms in order to solve tasks.

Not only is the brain great at solving complex problems, it does so while using very little energy

Jascha Achterberg

DeltaWorks

Graphic representing an artificially intelligent brain

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Rare genetic disease may protect Ashkenazi Jews against TB

cjb250 — Mon, 06 Feb 2023 20:00:02 +0000

In research published today in Proceedings of the National Academy of Sciences (PNAS), Cambridge scientists – with colleagues in the Netherlands, Spain, and Pennsylvania, USA – show that the same biological mechanisms that underlie Gaucher disease are also effective at clearing TB infection.

̽��ֱ��discovery – made while studying TB susceptibility in zebrafish – suggests that genetic variants that increase the risk of Gaucher also help protect against TB, giving them a selective advantage – that is, making the variants more likely to be passed down from generation to generation.

In 2021, an estimated 10.6 million people worldwide fell ill with TB and 1.6 million people died from the disease. Most people manage to clear the infection themselves, however – only around one in 10 to 20 people will go on to develop the disease.

Professor Lalita Ramakrishnan and colleagues from the ̽��ֱ�� of Cambridge and the Medical Research Council Laboratory of Molecular Biology, Cambridge, are interested in what makes some people susceptible to TB while others appear to be protected. She uses zebrafish to model human disease as it is relatively easy to manipulate zebrafish’s genetics, and their immune systems share many similarities with those of humans.

During their research, her team had previously found that zebrafish with mutations that impaired the digestion of proteins by lysosomes became more susceptible to TB. Lysosomes are components of our cells that break down unwanted materials, including proteins and fats, using enzymes. When a mutation affects the production of these enzymes, it can lead to a build-up of toxic materials.

One type of cell that is vulnerable to this build-up is the macrophage, a type of immune cell that ‘eats’ toxic material, including bacteria and waste products. In lysosomal disorders, the macrophages become enlarged because of accumulation of undigested material in their lysosomes and move slowly, hampering their ability to fight infection.

Professor Ramakrishnan said: “Macrophages need to move quickly to attack invading bacteria and viruses. Their name means ‘big eater’, and this is exactly what they do. But with lysosomal disorders, they’re unable to break down the food they eat, which makes them bloated and sluggish, unable to perform their duties.”

However, when Ramakrishnan and colleagues modelled a lysosomal storage disease known as Gaucher disease, they found something very unexpected: TB resistance rather than susceptibility.

Gaucher disease is a rare disease, affecting around one in 40,000 to 60,000 births in the general population, but rates are significantly higher among Ashkenazi Jews – around one in 800 births. In most cases, the disease can be relatively mild – with symptoms including enlarged spleen and liver, and anaemia – and around two-thirds of people carrying two copies of the most common genetic variant are unaware they are carriers.

When the researchers genetically engineered zebrafish with genetic variants causing Gaucher disease that are common among Ashkenazi Jews, as anticipated their macrophages became enlarged and unable to break down the toxic materials, in this case an unusual type of fat (called sphingolipids) rather than protein. But when the team exposed the fish to TB, they discovered unexpectedly that the fish were resistant to infection, not susceptible.

̽��ֱ��reason for this resistance to infection was because of the fatty chemical that accumulates within the macrophages in Gaucher disease, called glucosylsphingosine. Glucosylsphingosine was found to act as a detergent-like microbicide that kills TB mycobacteria within minutes by disrupting their cell walls.

Professor Ramakrishnan added: “We’d unknowingly landed in a debate that’s been going on in human genetics for decades: are Ashkenazi Jews – who we know are at a much greater risk of Gaucher disease – somehow less likely to get TB infection? ̽��ֱ��answer appears to be yes.”

̽��ֱ��Ashkenazi Jewish diaspora has experienced centuries of persecution, often forced to live in ghettos and migrate from country to country. They would almost certainly have been exposed to TB, which spreads more widely among poorer living conditions and densely-populated urban areas.

Although this genetic mutation is associated with Gaucher disease, the fact that it makes people more resistant to TB would likely have outweighed the potential fitness cost of Gaucher disease. This would have increased the likelihood of affected individuals passing on their genes to future generations and therefore spread the mutation within the population. A similar phenomenon is seen among some individuals who carry genetic variants that protect them from malaria but, when more than one copy is present, cause harmful anaemia or even sickle cell disease.

Unlike the example of sickle cell anaemia, however, only individuals who carry two copies of the Gaucher genetic variant – one from each parent – are likely to be protected against TB. That’s because the one ‘healthy’ gene generates enough of the enzyme to clear the macrophages of their accumulating material – and hence gets rid of the antimicrobial substrate.

Professor Timothy Cox from the ̽��ֱ�� of Cambridge, a co-author on the paper, added: “Our discovery may provide clues to possible new treatments for TB. Drugs that mimic the effects of Gaucher disease – specifically the build-up of glucosylsphingosine – might offer antimicrobial effects against TB.”

Several such drugs have already been designed by Professor Hans Aerts from Leiden ̽��ֱ��, another co-author on the paper. Because these drugs would only need to be administered for a relatively short amount of time, any side-effects should be limited and temporary.

̽��ֱ��research was funded by Wellcome, Gates Cambridge and the National Institute for Health and Care Research Cambridge Biomedical Research Centre.

Reference
Fan, J et al. Gaucher Disease Protects Against Tuberculosis. PNAS; 6 Feb 2023; DOI: 10.1073/pnas.2217673120

Scientists may have solved the question of why Ashkenazi Jews are significantly more susceptible to a rare genetic disorder known as Gaucher disease – and the answer may help settle the debate about whether they are less susceptible to tuberculosis (TB).

We’d unknowingly landed in a debate that’s been going on in human genetics for decades: are Ashkenazi Jews somehow less likely to get TB infection? ̽��ֱ��answer appears to be yes.

Lalita Ramkrishnan

halbergman (Getty Images)

Grandfather Helping Little Boy to Wash His Hands at Passover Seder with Family - stock photo

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Racial discrimination linked to increased risk of premature babies

Anonymous — Fri, 05 Aug 2022 08:16:17 +0000

̽��ֱ��findings add to growing evidence that racial discrimination is a risk factor for poor health outcomes, say the researchers.

For several decades, race has been recognised as a social determinant of health and a risk factor for numerous diseases. ̽��ֱ��evidence increasingly suggests that social, environmental, economic and political factors are fundamental drivers of health inequities, and that it is often racial discrimination or racism, rather than race, that is the root cause of racial disparities in health outcomes.

For example, maternal death rates among Black and Indigenous women in the USA are two to three times higher than those of white women. Similarly, in the UK, maternal death rates are two to four times higher among Black and Asian women compared to death rates among white women.

To explore the existing patterns of racial discrimination and adverse pregnancy outcomes, the researchers carried out a systematic review and meta-analysis, pooling and analysing data from the available evidence. This approach allowed them to bring together existing and sometimes contradictory or under-powered studies to provide more robust conclusions. Their results are published in the open access journal BMJ Global Health.

̽��ֱ��team searched eight electronic databases, looking for relevant studies on self-reported racial discrimination and premature birth (that is, before 37 weeks), low and very low birthweight, small-for-gestational age, and high blood pressure associated with pregnancy.

In all, the results of 24 studies were included in the final analysis. ̽��ֱ��majority of studies (20) were carried out in the USA. Study participants were of different racial and ethnic backgrounds, including Black or African American, Hispanic, non-Hispanic white, Mãori, Pacific, Asian, Aboriginal Australian, Romani, indigenous German and Turkish.

̽��ֱ��pooled analysis showed that the experience of racial discrimination was significantly associated with increased risk of premature birth. Women who experienced racial discrimination were 40% more likely to give birth prematurely. When low quality studies were excluded, the odds of a premature birth were reduced, but still 31% higher in those experiencing racial discrimination.

While not statistically significant, the results also suggest that the experience of racial discrimination may increase the chance of giving birth to a small-for-gestational age baby by 23%.

Co-first-author Jeenan Kaiser, who did her MPhil in Public Health at the ̽��ֱ�� of Cambridge and is currently a medical student at the ̽��ֱ�� of Alberta, said: “Racial discrimination impacts the health of racialised communities not only in direct and intentional ways, but also in how it shapes an individual’s experiences, opportunities, and quality of life. These are fundamentally driven by structural and social determinants of health.

“While our study focused on its impact on pregnancy outcomes, it is becoming increasingly evident that it negatively impacts a myriad of health outcomes. Efforts to counter racial discrimination and promote health must focus on systemic policy changes to create sustainable change.”

Co-first author Kim van Daalen, a Gates Cambridge and PhD candidate at the Department of Public Health and Primary Care, ̽��ֱ�� of Cambridge, said: “Dismantling structures and policies that enable institutional and interpersonal racial discrimination, underlying racial and ethnic disparities in health and intersecting social inequalities, is essential to improve overall health in societies. Partnerships of health care professionals with community-based reproductive justice and women’s health organisations who work in this area can improve health for racialised women in a community-centred way.”

̽��ֱ��researchers point out that racial discrimination impacts what health services and resources are available, such as referral to specialist care, access to health insurance and access to public health services.

Co-author Dr Samuel Kebede, who did his MPhil in Epidemiology at the ̽��ֱ�� of Cambridge as a Gates Cambridge Scholar and is currently at Montefiore Health System/Albert Einstein College of Medicine in New York City said: “Historically there have been countless examples of where medicine and public health have been furthered by the subjugation and experimentation of Black and indigenous people. But the influence of structural racism is still present within the healthcare system today. From segregated healthcare for uninsured and under-insured people of colour in the United States, to the global disparity in COVID-19 vaccinations, structures continue to perpetuate inequities. Health professionals can play a vital role in dismantling these systems.”

Many of the studies were of limited quality and included few marginalised racial or ethnic groups other than African Americans; as such, their applicability to other ethnic groups and cultural settings may be limited. However, the researchers argue that when pooled, the data clearly demonstrate the negative impact of racial discrimination on pregnancy outcomes.

Reference
van Daalen, KR, & Kaiser, J et al. Racial discrimination and adverse pregnancy outcomes: a systematic review and meta-analysis. BMJ Global Health; 3 Aug 2022; DOI: 10.1136/bmjgh-2022-009227

Women who experience racial discrimination on the basis of their ethnicity, race or nationality are at increased risk of giving birth prematurely, according to a team led by researchers at the ̽��ֱ�� of Cambridge.

Racial discrimination impacts the health of racialised communities not only in direct and intentional ways, but also in how it shapes an individual’s experiences, opportunities, and quality of life

Jeenan Kaiser

Ariel Skelley (Getty Images)

Black woman holding newborn baby in hospital bed

Yes