Four things you should know about the HIV "cure" before you get too excited

The baby might not even have been infected in the first place.

The story everyone is talking about today is the HIV "cure" - the Mississippi baby who, after being blasted with a cocktail of anti-viral drugs at birth, is now, at two years old, apparently virus-free. But when reading the euphoric news stories about it here, here and here, you should bear the following in mind:

1. The baby may not even have been infected in the first place

Here's a weird section in the NYT version of the story. Have a read of the following two paragraphs - are the doctors certain or uncertain that the baby was infected?

“The one uncertainty is really definitive evidence that the child was indeed infected,” said Dr. Daniel R. Kuritzkes, chief of infectious diseases at Brigham and Women’s Hospital in Boston.

Dr. Persaud and some other outside scientists said they were certain the baby — whose name and gender were not disclosed — had been infected. There were five positive tests in the baby’s first month of life — four for viral RNA and one for DNA. And once the treatment started, the virus levels in the baby’s blood declined in the pattern characteristic of infected patients.

The tests are pretty good, but are not usually trusted as a basis for confirmed diagnosis at that early stage. It is normal practice to confirm positive tests at 6 weeks. But as this baby had already been treated by then, lowering its viral load (negative tests came back at 29 days), it would have been difficult to do this. There is a very small chance the baby was not infected.

The virus may not have yet taken a hold on the baby's cells in a permanent way. Here's the WSJ:

Cells in the baby "may have been infected—there was virus around," said Steven Deeks, an AIDS researcher at University of California at San Francisco. "But the cells being infected weren't the type that become long-lived reservoirs."

There is also a small chance the baby was immune to HIV anyway. Around 1 per cent of Caucasians in the US are naturally immune.

Now, these are small chances, but then this baby is an outlier. It was not part of a large study where such anomalies are ruled out. The scientists have said it is unlikely to be replicable. Any way you put it, the baby itself is an anomaly.

2. This "cure" has already been found, and has been used on newly-infected people since 1987. Even if the baby was infected, today's news would simply extend it to newborns.

Today's news applies only to babies. Newborns at that. And it's not really a new method - rather, it's the same idea as PEP: if you have only just been infected, you might avoid HIV if you are immediately given a large amount of anti-HIV drugs. What the scientists confirmed today is that, in terms of emergency treatment, newborns are the same as newly-infected people. 

Here's the NYT again:

“That goes along with the concept that, if you treat before the virus has had an opportunity to establish a large reservoir and before it can destroy the immune system, there’s a chance you can withdraw therapy and have no virus,” said Dr. Anthony S. Fauci, the director of the National Institute for Allergy and Infectious Diseases.

(Oh, and if you were wondering, someone has actually been cured of AIDs before. This was a man called Timothy Brown, a leukemia sufferer who received a bone-marrow transplant from a donor genetically resistant to HIV.)

3. This would not be breaking much ground in preventing HIV in newborns anyway, because we have a solution for that

In countries with access to top-notch medical care (ie western countries), the transference of HIV from mother to child is extremely rare. This is because mothers are treated with antiretroviral therapy during pregnancy - a very effective way of preventing HIV in newborns.

4. Newborns in countries without a solution for that probably wouldn't get this treatment anyway

In countries without access to top-notch medical care, there is no reason that this treatment would be available where antiretroviral pregnancy treatment isn't.

So what does the news mean? Well it means that a few babies in countries with access to this sort of care but whose mothers have somehow slipped through the net of normal practice can be saved. Joyous news. But not quite as joyous as everyone seems to be making out.

UPDATE: This blog originally said that HIV tests at birth couldn't be accurate, but this applies only to antibody tests. The tests on DNA/RNA, which were done in this case, have a greater (although not 100 per cent) degree of accuracy.

HIV cure: not necessarily.. Photograph: Getty Images

Martha Gill writes the weekly Irrational Animals column. You can follow her on Twitter here: @Martha_Gill.

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The anti-chemical weapons technology that could help rebuild Syria

A new compact chemical agent clean-up system offers hope to formerly deadly conflict zones.

The US “Defense Advanced Research Projects Agency” (Darpa) is an elite organisation tasked with developing secretive military technologies. True to form, its logo is oddly reminiscent of a supervillain’s – imposing and stark. Some of its projects, too, are futuristic weapons with darkly amusingly self-aware names, such as Mahem - a kind of self-forging molten metal spear that can penetrate armour. But not all of Darpa’s programmes add to the chaos of conflict. They have recently developed prototypes of a self-contained treatment system to neutralise chemical weapons and “scrub” the chemical-tainted earth clean.

 

Recently it has been impossible to avoid seeing the effects of chemical weapons. Clips of Syrian children simultaneously suffocating and crying uncontrollably as a result of the nerve gas sarin have become disturbingly ubiquitous, even despite chemical agents in warfare being banned. Less well-known, however, is the fact that chemical weapons are so toxic that the ground that they touch becomes unsafe.

The default methods for dealing with conventional munitions are usually open incineration or controlled detonation, also used for some chemical weapons – but the method, as well as the facility where neutralisation can occur, depends on the kind of chemical that has been weaponised. There are four types of chemical agent, which can be liquidised or in gas form. Each has a unique persistence (length of time it can remain dangerously concentrated in a given environment), and target: attacking the nervous system, the respiratory system, the blood, or cell tissues.

An ex-US Navy analyst once divulged to me that one of the reasons why chemical weapons are used in Syria is because they trigger an immediate halt to any plans for ground troops to be deployed in the affected area. Without knowledge of which agent was used, there is the risk that personnel do not have the relevant personal protective equipment, and they cannot be sent in unprepared. At the moment, troops are given masks and skin decontamination lotion kits, but scientists are also developing systems to protect soldiers against chemical attacks. The most hopeful potential is a caged “bioscavenger” – small enough to circulate (undetected by the immune system) throughout the bloodstream to counter the poisonous impact of certain chemical agents.

However, for civilians in the warzone, the effects are much longer lasting. Even after the agents have mostly dissipated in the air, and become dilute enough to breathe in, the ground retains some toxic qualities from the weapon’s decomposition. Darpa’s new machine – the “Agnostic Compact Demilitarization of Chemical Agents” (ACDC) – is significant because it is “agnostic”, i.e. unspecific to one kind of chemical weapon. The self-sufficient neutralisation units can also be used to safely dispose of bulk stockpiles of chemical agents alone and with any kind of contaminated soil. There are two distinct systems, a “dry pollution control process” that is suitable for arid soil, and a “wet” one that uses a slightly different procedure.

Darrel Johnston, senior programme manager for ACDC’s developer – Southwest Research Institute’s chemistry and chemical engineering division – said that “it is in [the US’s] national interest to have a field operable unit that can safely dispose of chemical warfare agents and other dangerous chemicals on the front lines in a timely manner."

The ACDC works similarly to a catalytic converter in a car, which makes polluting gases less toxic - it neutralises residual salts and acidic gases. Initial indoors tests demonstrated a probable 99.99 per cent success rate of eliminating all harmful by-products of chemical weapons usage. The resultant non-hazardous compounds can be left in the ground, without posing a risk to the environment or anyone’s health. This is a much “greener” course of action than conventional destruction techniques, which are typically very complex and require several stages due to inefficient treatment of waste.

Two of the most significant aspects of ACDC are its portability, as it is compact enough to fit into a shipping container, and its low cost. Doug Weir, manager of the Toxic Remnants of War Project, told me that there are many legacy cases, such as the WWII mustard shells abandoned on the Pacific Islands, “where infrastructure is limited and where the scale of the problem doesn't justify the price tag of a formal facility - where a mobile system would be really valuable”.

There are already attempts to neutralise the after effects of chemical weapons in Syria, but up until now, each weapon has required a different kind of method, which makes the process expensive and wasteful. According to Weir, regarding the logistical and security nightmare of processing roughly 1,300 tonnes of Syrian chemical weapons, the priority is likely to have been removing the weapons from the conflict zone “at all costs”. However, “there were a number of environmental groups who raised concerns about waste disposal from the [at-sea] process”. This is because each of the numerous methods used (one per chemical compound) yielded risky by-products that later had to be broken down further. Overall, the process has cost in the hundreds of millions of US dollars and generated 5.7 million litres of waste. In contrast, Darpa hopes that ACDC will cost just 1 per cent of the Syrian mission.

Although this all sounds optimistic, Gwyn Winfield, Editorial Director of CBRNe World, reminded me that “any system that attempts demilitarisation needs, by its nature, to be in a permissive environment”, meaning that Syria would have to be stable enough for ACDC’s arms control work to be meaningful.

Similarly, Dr. Michelle Bentley, author of Syria and the Chemical Weapons Taboo: Exploiting the Forbidden, told me that “this technology will not challenge the political problems behind chemical weapons use”. In particular, Assad has proven unwilling to part from his chemical stockpiles. She added that “we can’t just think about what we do about chemical weapons – we have to think more about how we do it”.

At the moment, the constraints on outside forces are such that the UN allowed the Syrian army to accompany inspectors to all of Assad’s chemical production and storage facilities, even those in rebel-held territory. The resulting tensions made it clear that – rather than technology being the limiting factor – the biggest task would be mitigating the political pitfalls of disarmament in such a polarised country. It is impossible to tell when Syrian air will be safe for civilians to breathe, or its soil will stop being too toxic to grow food.

However, those who have been forced from their homes by the noxious attacks may take some comfort in the knowledge that once the lab testing stages are over, Darpa plans to use ACDC in the field. If successful, ACDC will be rolled out as part of standard US military vehicles so that any chemical agent (combined with any kind of soil) could be neutralised, and former conflict zones might become slightly safer and healthier.

For now, at least ACDC can offer the hope of a clean start.

 

Anjuli R. K. Shere is a 2016/17 Wellcome Scholar and science intern at the New Statesman

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