Category Archives: Health

Health, Medical, Research, Science

Could a new ‘universal vaccine’ stop all strains of flu virus?

MEDICAL RESEARCH

A NEW universal long-lasting vaccine could prevent the need for yearly flu jabs.

Currently, scientists have to predict every year what the new strain of flu will look like, but by the time the vaccine has been made, the strain of virus may already have mutated and changed.

Recently released figures reveal the vaccine given to ten million over-65s, children and at-risk adults last year offered little protection against the killer H3N2 strain, known as Aussie flu, which put unprecedented pressure on the NHS during the winter months.

Public Health officials have admitted the jab had “no significant effectiveness” in preventing people from being struck down – and was deemed only 15 per cent effective overall.

UK researchers are now working on a “universal” vaccine to protect against a number of strains.

The cells of the flu virus are like spherical cushions with lots of pins sticking out. Flu vaccines currently work by triggering an immune response to antigens – the heads of the pins – on the cell’s surface.

The immune system creates antibodies, which are then primed to attack and block the real flu virus when it comes along: the antibodies recognise the virus by its antigens.

The new vaccine, developed at the University of Oxford, protects the body against flu in a way that makes it more universal.

 

SCIENTISTS have found that while flu strains vary, all flu viruses contain epitopes (parts of the antigen to which antibodies attach), which vary much less than previously thought. Targeting these epitopes through vaccination would protect against all strains of the virus.

The new vaccine is designed to home in on these common epitopes and help the immune system create antibodies to fight them.

So far they’ve identified specific epitopes for two main types of flu – influenza A virus (subtypes H1 and H3) and influenza B. Researchers say a vaccine using this new approach could provide immunity without the need for yearly vaccinations, and could work against many types of flu even if the virus mutates.

Two or three injections would give long-term protection against different strains, they say.

Sunetra Gupta, a professor of theoretical epidemiology who led the research, says: “We believe our methods can be applied to produce vaccines against all subtypes of influenza, thereby providing the opportunity to develop not only a more effective vaccine against endemic influenza, with lower healthcare costs, but also better protection against potential influenza pandemics.

“The same strategy can also be used to produce vaccines for swine and avian influenza, which will have significant economic consequences, and the control of which will reduce the probability of new lineages emerging with pandemic potential.”

Vaccination is the most effective way to protect against the virus and is given annually in the UK to people at risk, including the over-65s, children aged two to nine, pregnant women, and people in long-stay residential care homes.

But the problem with existing vaccines is that the flu virus frequently mutates in two ways.

The first, known as antigenic drift, involves small changes in the genes of influenza viruses as the virus replicates.

These small genetic changes usually produce viruses that are closely related to one another, and share the same antigenic properties, so an immune system exposed to a similar virus will usually recognise it and respond.

But these small changes can accumulate over time and eventually the immune system may not recognise them and respond.

The less common route is antigenic shift – an abrupt, major change in the influenza A virus, and most people have little or no protection against the new virus.

 

TO ENSURE vaccines are available when needed, six months before the flu season, scientists try to predict the new strain. However, as the latest figures show, they don’t always get it right.

Commenting on the research, Professor Wendy Barclay, the Action Medical Research Chair in Virology at Imperial College London, says: “There are lots of different ideas about to make a universal flu vaccine and how universal it would actually be.

“This work from the Oxford group would mean we don’t have to update the flu vaccine yearly, but if a new pandemic came along, chances are this type of vaccine wouldn’t work against that.

“But it would mean we don’t have to chase after the virus as it constantly drifts and we try to keep up.”

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Health, Medical, Research, Science

Blood pressure study linked to dementia

MEDICAL RESEARCH

A major study suggests that hundreds of thousands of people could be saved from dementia if blood pressure tablets were used more widely.

Researchers have shown for the first time that aggressively treating high blood pressure – particularly in middle age – could also significantly reduce the risk of dementia later on.

NHS officials are under growing pressure to lower the threshold at which people can be given the drugs, a policy that could make 14million eligible for treatment.

Patients are currently considered to have hypertension – or high blood pressure – only if they have a reading of more than 140/90 mm Hg.

But a study of 9,400 people in the US found cutting the systolic threshold – the higher reading – to 120 instead of 140 slowed cognitive decline.

An ideal blood pressure reading is between 90/60 millimetres of mercury (mm Hg) and 120/80. The first figure is the systolic pressure, the “surge” that occurs with each heartbeat. The second is the diastolic reading, which measures the pressure in the “rest” between heartbeats.

Using the new threshold over eight years reduced rates of dementia and mild cognitive impairment by 15 per cent, according to results presented at the Alzheimer’s Association International Conference in Chicago.

Similar trials have shown cutting the threshold for treatment would reduce the risk of heart disease by a fifth, and strokes by about a quarter.

Health watchdogs are already reviewing blood pressure guidelines with a view to cutting rates of heart disease and a decision is expected next year.

But they will now face greater pressure to change the rules after the new research, the first to look in detail at the impact of such a policy on dementia.

Study leader Professor Jeff Williamson, of the Wake Forest School of Medicine in North Carolina, said: “These results support the need to maintain well-controlled blood pressure, especially for persons over 50.”

A second study of 670 patients by the University of Pennsylvania found that the lower threshold also showed shrinkage of white brain matter, strengthening the link between blood pressure and dementia.

The US has led the way on blood pressure policy, lowering the treatment threshold in November from a systolic score of 140 to 130.

If the UK followed suit, it would mean an estimated 14million people – a third of all adults – would be eligible. Currently seven million are eligible.

A policy to increase this, however, would be controversial as it would affect many people who until now have been considered healthy. A similar change that lowered the threshold for cholesterol-busting statin drugs in 2014 led to a huge backlash, fueling accusations that health professionals were “over-medicalising” the middle aged.

A spokesperson for Alzheimer’s Research UK, said: “This study suggests treating high blood pressure intensively . . . may help to reduce the risk of memory and thinking problems.

“There is robust evidence that what’s good for the heart is also good for the brain and maintaining good vascular health is one of the key things people can do to reduce their risk of dementia.”

But Professor Clive Ballard, of Exeter University, warned: “All anti-hypertensives come with some risk of adverse effects, most seriously for kidney function.”

 

THOSE who feel light-headed when standing up after a long time sitting may be at a greater risk of dementia and stroke, according to a US study of more than 11,000 people.

Scientists at John Hopkins University found those whose blood pressure dropped when they stood up – a problem known as orthostatic hypotension – had twice the risk of suffering a stroke in later life. Their risk of dementia was 54 per cent higher.

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Arts, Environment, Government, Health, Science, Society, United Nations

How Can We Deal With Global Population Growth?

POPULATION GROWTH

Intro: With population numbers projected to continue to swell over the course of the twenty-first century, there are some pressing questions that remain unresolved. We should turn to science in search of solutions to Earth’s depleting space and resources.

THE subject of global population growth can be an emotive one, and many accounts of rising populations are accompanied by dire warnings of impending catastrophe. Concern about population growth is by no means a modern phenomenon, though. In 1798, the British cleric Thomas Malthus published An Essay on the Principles of Population, in which he addressed the potential problems that could develop due to the rapidly rising population in Britain at that time, a consequence of the Industrial Revolution. He argued that populations had the capacity to grow more quickly than food production, writing, “The power of population is so superior to the power of the earth to produce subsistence for man, that premature death must in some shape or other visit the human race.” It would become a highly influential concept and one that would reach beyond demography alone – acknowledged, for instance, by Charles Darwin as having been one of the key ideas that led to his theory of evolution by natural selection, which described competition for resources as being one of the driving forces behind evolution.

The Population Bomb

In 1968, the American entomologist and environmentalist Paul Ehrlich wrote in Malthusian terms in The Population Bomb of an upcoming catastrophe, in which many millions of people would die of starvation. Though not the first publication to examine the so-called “population problem”, its popularity introduced the issue to a much wider audience. It was followed in 1972 by the even more widely read The Limits to Growth, a collaborative report commissioned by the political think tank the Club of Rome. Both works were relatively sober, informed assessments, but were followed by a range of sensationalist books and articles, containing various prophecies of doom – which remain a feature of environmental discussion today.

Paul Ehrlich

Paul Ehrlich, whose book brought the population problem to the attention of a much wider audience.

In The Population Bomb, Ehrlich wrote that the Earth could support two billion people before disaster ensued – a figure that had already been exceeded by more than a billion at the time the book was published. Now, almost 50 years later, the predicted catastrophic collapse has not occurred (at least not yet anyway). In July 2015, the Population Division of the United Nations Department of Economics and Social Affairs in New York released the annual revision to its 2010 population census, providing estimates of the global population over the course of this century. According to this, the global population was 7.3 billion in 2015, and was expected to continue growing, reaching 10 billion by the middle of the century and 11.2 billion by 2100, by which time the rate of growth is expected to have slowed – before stabilising and perhaps beginning to fall.

By no means do all demographers agree with the UN figures. The wide variation between experts’ population predictions is a consequence of the number of unknown factors involved, and because in reality people rarely behave exactly as expected. But, if we take the UN figures as a reasonable estimate, over the next three to four decades an additional 3 billion people will inhabit the world, and the total figure will be five times higher than Paul Ehrlich’s estimated carrying capacity of the Earth.

The Impact of Science

One of the ways science has helped to avert potential disasters is through agricultural research aimed at increasing food produce. One of the best-known examples of this is the Green Revolution on the Indian subcontinent, which began in the 1960s – a period when India and Pakistan were experiencing population booms that appeared to be outstripping the capacity of the region’s agriculture to produce enough food for everyone. New varieties of high-yielding wheat, developed by the American agronomist Norman Borlaug at a research station in Mexico, were transferred to the subcontinent, greatly increasing agricultural productivity and averting the potential for widespread famine.

Subsequent research produced new varieties of other staple crops, including rice, and these, together with the use of new technologies in the shape of farm machinery, fertilisers and pesticides, have had a dramatic impact on the amount of food produced – even if these technical advancements can come with social and environmental costs. It has become clear that new technology on its own is not a complete solution, though, and extreme poverty can lead to people remaining malnourished despite there being no local food shortages, through not having land to grow crops themselves or the means to buy enough food.

Science can also help in the field of healthcare, through the development of medical technology and drugs that address the particular problems causing high levels of child mortality, which are often encountered in those parts of the world where high rates of population growth occur. When such technologies are combined with more widely available healthcare services, the resulting reduction in child mortality often leads to lower rates of population growth. Put simply, women have fewer children in places where those children are more likely to survive into adulthood, and so population numbers gradually begin to stabilise.

Hope For The Future

The UN figures show that growth rates have already slowed down in many parts of the world. Europe, North and South America and Oceania now show no growth at all, and nor does much of Asia, with the notable exceptions of India and Pakistan. About three-quarters of the population growth set to occur over the course of this century is projected to be on the African continent, and this rise will almost all be as a consequence of people living longer, rather than an increase in the number of children being born. This statistic is key to gaining an understanding of how population growth should slow down and eventually stabilise in the future; improvements in healthcare initially lead to a rapid rise in life expectancy, so, rather than a rising population being caused by more children being born, it is actually a consequence of there being an increased number of older people. Over time, the initial rapid increase in life expectancy will tend to level off and, at this point, the population will stop rising as well.

 

IN the future, then, there will be many more people in the world, and it does appear that population growth is set to continue in the long term. The challenges ahead are to grow enough food, to alleviate extreme poverty and to provide adequate healthcare for the entire global population.

Alternative Theories

UNLIKE the doom merchants who have until recently dominated the public debate on population growth, the Swedish doctor and statistician Hans Rosling describes himself as a possibilist, believing not only that the Earth can support 11 billion people, but that all of them can enjoy a good quality of life. He appears to be on a mission to make population statistics entertaining as well as informative, making use of dynamic graphics to illustrate his lectures and enlivening proceedings with plenty of comical jokes, mostly at his own expense.

To take just one example of many, Rosling describes the washing machine as being one of the great inventions of the twentieth century because of the impact it has had on freezing women from domestic drudgery, allowing them the time to do other things, like going to university or by seeking an alternative career. As he points out, the statistics show that as women become better educated, they gain more control over their lives – over the age at which they start a family and the number of children they have. Where they have the choice, many women opt to have children later in life than their mothers and grandmothers did, and often prefer to have two or three children rather than five or six. This phenomenon has been seen around the world and has often occurred over the course of a single generation. Rosling is not trying to say that this is entirely caused by the washing machine, rather using it to illustrate the point that the empowerment of women has been one of the driving forces behind the observed reduction in population growth rates.

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