Medical, Research, Science

Will we ever develop a vaccine for HIV?

MEDICAL SCIENCE

Intro: In 1983, HIV (human immunodeficiency virus) was found to be the cause of a range of conditions collectively known as AIDS (acquired immune deficiency syndrome). Over 35 million people have since died due to HIV, and the same number live with it.

THE high number of HIV cases and deaths worldwide is in part because the antiretroviral drugs that have been available since the mid-1990s, allowing infections to be managed, are not always widely available in certain parts of the world – namely in Africa, where HIV infection rates are the highest. But also, unlike many other viral diseases, attempts to develop a vaccine for HIV have so far been unsuccessful.

Vaccination against a variety of infectious diseases is now such a routine part of healthcare that it is easy to forget how important it has been in the history of medical science. Many millions of deaths have been prevented since the principles of vaccination were established by the English physician Edward Jenner in the late eighteenth century. Jenner had become aware of local knowledge near his home in Gloucestershire; milkmaids who had previously caught cowpox, a relatively mild disease, did not then suffer from the similar but much more serious, and potentially fatal, smallpox. Jenner conducted trials in which he exposed people to cowpox and some weeks later to smallpox, finding that the more serious and virulent form of the disease did not develop as predicted. It represented the beginning of a long process, which culminated in 1979 when, after a decades-long programme of vaccination, the World Health Organisation (WHO) was able to announce that smallpox had been completely eradicated.

The Success of Vaccines

Great advances in our understanding of how vaccines work was made in the late nineteenth and early twentieth centuries by, among many others, Louis Pasteur, Robert Koch and Paul Ehrlich (the German physician and not the American environmentalist of the same name associated with the study of global population growth). The way in which the immune system works – through the production of antibodies – was discovered, and methods of producing vaccines extended from Jenner’s use of a related mild disease to the use of killed or weakened forms of the original infectious agent, allowing vaccines for a greater range of diseases to be developed. Vaccines were developed for one infectious disease after another, perhaps most famously including the vaccine for polio, developed in 1955 by the American virologist Jonas Salk.

The Trouble With HIV

In among the remarkable successes, vaccines for a few infectious diseases remain frustratingly out of reach. HIV has the ability to evolve quickly, making it difficult to produce a vaccine that will be – and will remain – effective against all the different strains. A further complication arises because it initially evolved to attack the immune system, which has given the virus a complicated surface structure that enables it to evade detection. Vaccines work by stimulating what is known as the adaptive immune system, the part of the system that can remember the structure of pathogens, so that when these are encountered again the immune response will be enhanced. In the case of HIV, the usual ways of producing a vaccine do not work because it is not detected in the first place, so the immune system is not stimulated.

As if the problem of producing a vaccine was not already complicated enough, further difficulties arise because the two usual methods for producing active agents for vaccines have not worked for HIV. Most vaccines have been developed using either a killed or deactivated (attenuated) version of the pathogen, so that it stimulates the immune system without causing harm. HIV that has been killed does not stimulate an immune response, while the complex structure of the virus means that attempting to deactivate it is difficult. Using an attenuated version would run the risk of infecting the patient.

A formidable range of obstacles still exists, but over 30 years of research have provided medical researchers with a huge body of knowledge on HIV, leading many scientists to be optimistic about a future cure. In the meantime, advances in the management of the disease mean that those with HIV, with access to the relevant drugs, can expect to lead an almost normal life. Until a vaccine is found, the challenge remains to extend these treatments to as many people as possible.

Alternative Theories

HIV suppresses the immune system by invading and attacking T cells, which play a crucial role in what is known as cell-mediated immunity. It was thought that, once the virus had invaded a T cell, it replicated and then spread to other T cells through the blood. Recent research has found that it can actually spread much more quickly, by utilising short-lived connections between T cells in order to transfer directly from one cell to another. This may help to explain why those vaccines developed so far have not been very effective, because these have only worked against HIV in the blood, and it may also open up the possibility of new forms of treatment that in some way block this cell-to-cell transmission.

Recommended/Supplementary Reading:

. National Geographic: Ancient “Giant Virus” Revived From Siberian Permafrost

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Health, Medical, Science

Mindfulness

WELL-BEING & MENTAL HEALTH

Mindfulness

I ran a series of tweets on mindfulness over the past 10 days on the social media networking site Twitter. I have listed here in consolidated form, from the earliest to the most recent.

Attached below is a link that will display the content in PDF format.

Extracts:

‘The experience of people who practise mindfulness is now being backed up by science. Within the past few years, neuroscientists have been using MRI technology to look at the brains of people who meditate. The results have been fascinating.’

‘Mindfulness training draws on the ancient traditions of meditation and yoga, often incorporating insights from modern medicine and psychotherapy.’

‘Buddhist thinkers have taken great interest over the centuries in the way the human mind works.’

‘In the 1990s, mindfulness took a quantum leap into the world of mental health and psychotherapy when three leading psychologists from the UK and Canada developed Mindfulness-Based Cognitive Therapy (MBCT) as a treatment for people with a history of recurrent depression.’

‘Mindfulness can help us to cope better with a range of conditions including chronic pain and heart disease. It has been shown to strengthen the immune system, improving our responses to illnesses ranging from flu to psoriasis and even to HIV.’

The range of content shared can be viewed here (PDF format) > MINDFULNESS

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Arts, Books, Medical, Society, Syria

Book Review – War Doctor: Surgery On The Front Line

MEMOIR

Syria, 2012 – Location: Atmeh. A woman was rushed to the operating theatre with severe bomb damage to her leg.

Dr David Nott, a trauma surgeon, clamped the artery to prevent her from bleeding to death and gently pressed a finger into the gaping hole above her knee joint. He felt an object. It was probably some kind of shrapnel, but it was strangely smooth and cylindrical.

Dr Nott grabbed it with his fingers – “very carefully”, he recalls – and pulled it out. Once extracted he held it up to examine it. His Syrian helper took one look and went visibly pale; he obviously knew what was being presented and blurted out, “Mufajir!” before turning tail and leaving the room.

Nott and the anaesthetist locked eyes in panic. Was this some kind of bomb? The room fell silent, bar the hiss of the patient’s ventilator. The anaesthetist backed away and Nott felt his hand begin to shake so vigorously, he was in danger of dropping the thing.

Then the Syrian helper rushed back in with a bucket of water and motioned for Nott to place the metal object carefully into the bottom of it. He later learned that “mufajir” means “detonator” and it could have blown off his hand.

The woman was injured when a bomb her husband had been making in their kitchen had prematurely detonated, killing him instantly.

You can sense Dr Nott’s frustration and anger at the speed with which the Syrian civil war escalated. It had begun in March 2011, when a peaceful protest against the oppressive regime of Bashar al-Assad was met with shocking brutality.

By chance, Nott had met al-Assad in the early 1990s, when the dictator-in-waiting was working as an ophthalmic senior house officer at the Western Eye Hospital, London.

“He seemed very pleasant and respectful,” recalls the surgeon who would later treat Assad’s victims, including a heavily pregnant woman whose unborn child had been shot through the head by a sniper.

In his devastating memoir of more than two decades volunteering his services in some of the world’s most dangerous places, Nott doesn’t speculate on what changed al-Assad’s attitude to his fellow human beings.

He does, however, pinpoint the precise moment that a shy boy from rural Wales realised he wanted to become a “war doctor”, his epiphany occurring in 1985 when he first qualified as a surgeon. His parents took him to the cinema to see The Killing Fields (Roland Joffe’s 1984 drama about the civil war in Cambodia).

Nott’s father, also a doctor, was born in Burma and Nott had endured racist bullying as a child.

“The film lit a torch in me,” he says. “I could relate to its themes of innocent people being bullied, pushed around or dismissed. It gave a vivid depiction of the horrors of war. But, more than that, the film depicted the incredible power of human love in the face of unimaginable adversity.”

Some eight years later, Nott was standing over an operating table in Sarajevo. He had taken a month’s unpaid leave from the NHS to volunteer for the French aid organisation Médecins Sans Frontieres. The Bosnian civil war opened his eyes to a new medicine, in which decisions had to be made quickly, without the diagnostic tests and specialist equipment on which he had come to depend.

“I had never seen injuries like the ones that were coming in every hour.”

 

THE damage inflicted by bombs and high-velocity bullets was of an entirely different order from those received in even the most catastrophic trauma car accidents.

Multiple limbs were often missing. Many patients were dead on arrival, accompanied by relatives begging for help that Nott could not provide.

When he could attempt surgery, the hospital generators would often fail, and the team would have to wait until a porter brought in a wheelbarrow full of car batteries to get the theatre functioning again.

When bombs fell on the hospital itself, Nott’s team fled, leaving him alone in the dark, his hands around the failing heart of a teenage boy.

Stumbling from the room, soaked in his patient’s blood, Nott felt angry and betrayed. But he soon learned that, as an aid worker, his first duty was to keep himself alive so that he could help more people.

It was the first of many difficult moral choices he would have to make in Afghanistan, Sierra Leone, Chad, the Ivory Coast, Libya, Gaza, the Democratic Republic of Congo, Iraq and Pakistan.

In his scrubs, would you defy the Taliban policeman forbidding you to treat a woman bleeding to death in childbirth? Would you save the life of an ISIS fundamentalist likely to kidnap you on recovery? Would you give money to the children of dead patients?

Dr Nott had to make all these calls under extraordinary pressure.

He describes numerous near-death experiences and there was some terrible emotional fallout.

After returning from one mission, Nott found himself unable to bear the complaints of a British patient fretting about her “unsightly” thread veins and began a screaming, feigned sciatic attack until she left his consulting room.

He also had a panic attack when invited to a private lunch with the Queen. Overwhelmed by the contrast between the luxury of Buckingham Palace and the desolation he had seen in Syria, Nott found himself unable to answer Her Majesty’s questions.

As visions of limbless children filled his head, she placed her hand gently on his and encouraged him to pet her dogs. “There,” she said. “That’s so much better than talking, isn’t it.”

These days, the 63-year-old medic still travels the world to help victims of disaster. But his priorities changed after meeting his wife, Elly, at a charity event for Syria Relief in 2013.

The relationship came as a “bolt from the blue” to the man with a “monastic existence”. But, before they could arrange a first date, Nott made a trip to Gaza, where he elected to stay in the operating theatre to save the life of a little girl called Aysha, even though he had been ordered to evacuate the hospital because an airstrike was expected in minutes.

It was a story that Dr Nott told on Radio 4’s Desert Island Discs in 2017, reducing listeners to tears as he described how he still treasures the photograph he has of her, smiling as she recovered.

David married Elly in 2015 and welcomed daughter Molly the same year. Elly – an Oxford graduate with an MA in international relations – was the chief executive of the David Nott Foundation (a charity training surgeons to work in conflict zones) until the beginning of 2019.

Although as a husband and father, Nott tries harder to avoid danger, he finds it hard to be optimistic about the situation in Syria.

But he remains committed in continuing to train doctors working there.

On the final page of his book, Nott quotes the Koran: “Whoever saves a life, it shall be as though he had saved the lives of all mankind.”

– (Memoir) War Doctor: Surgery On The Front Line by David Nott is published by Picador for £18.99, 304pp

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