A human white blood cell infected with HIV virus -- 40 years after the first cases of what would come to be known as AIDS were documented, there is still no vaccine Photo: National Institutes of Health/AFP
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Four decades on, where's the HIV vaccine?

12 Comments
By Issam AHMED

In the four decades since the first cases of what would come to be known as AIDS were documented, scientists have made huge strides in HIV treatment, transforming what was once a death sentence to a manageable condition.

What we still don't have is a vaccine that would train human immune systems to ward off the infection before it ever takes root.

Here's the state of play on some of these efforts, which experts see as the "holy grail" in the fight to eliminate a virus that 38 million people live with globally.

Why do we need a vaccine?

More people than ever now have access to medications called antiretroviral therapy or ART, which when taken as prescribed, keeps down the amount of virus in their body.

This keeps them healthy and unable to transmit HIV to their partners.

Beyond ART, people at high risk for infection can now get pre-exposure prophylaxis, or PrEP, a pill taken every day that reduces the risk of infection by 99 percent.

"But access to medication is not organized in every part of the world," Hanneke Schuitemaker, global head of viral vaccine discovery at Johnson & Johnson's Janssen Vaccines, told AFP.

Even within wealthy countries, wide socio-economic and racial disparities exist in accessing these medicines, and vaccines have historically been the most effective tools to eradicate infectious diseases.

J&J is currently carrying out two human efficacy trials for its HIV vaccine candidate, and initial results from one of them may come as early as "the end of this year," Schuitemaker said.

Why is it so challenging?

Vaccines against COVID-19 were developed in record time and have shown remarkable levels of safety and efficacy, helping drive down caseloads in the countries fortunate enough to have wide access.

Many of these shots were developed using technologies that were previously being tried out on HIV -- so why haven't we had breakthroughs yet?

"The human immune system doesn't self cure HIV, whereas what was very clear was the human immune system was quite capable of self curing COVID-19," Larry Corey, principal investigator of HVTN, a global organization funding HIV vaccine development, told AFP.

COVID vaccines work by eliciting antibodies that bind to the virus' spike protein and stop it from infecting human cells.

HIV also has spike-shaped proteins on its surface, which are the target of HIV vaccine development.

But while COVID has tens of well known variants circulating worldwide, HIV has hundreds or thousands of variants inside each infected person, William Schief, an immunologist leading development of an mRNA HIV vaccine at Scripps Research Institute told AFP.

Because it's a "retrovirus" it quickly incorporates itself into its host's DNA. An effective vaccine will need to stop the infection dead in its tracks, not just reduce the amount of virus and leave the remainder to stay with the person forever.

Where do things stand now?

Efforts to develop a vaccine have been going on for decades but have so far all ended in failure.

Last year, a study called Uhambo that was taking place in South Africa and involved the only vaccine candidate ever shown to provide some protection against the virus frustratingly ended in failure.

J&J's vaccine candidate is currently being trialed in 2,600 women in sub-Saharan Africa in the Imbokodo trial, which is expected to report results in the coming months.

It's also being tested in around 3,800 men who have sex with men and transgender individuals across the US, South America and Europe in the Mosaico trial.

The J&J vaccine uses similar adenovirus technology to its COVID-19 vaccine, in other words a genetically modified cold virus delivers genetic cargo carrying instructions for the host to develop "mosaic immunogens" -- molecules capable of inducing an immune response to a wide variety of HIV strains.

This is followed up by directly injecting synthetic proteins in later doses.

Another promising approach is to try to generate "broadly neutralizing antibodies" (bnAbs) which bind to areas of the HIV virus that are common across its many variants.

The International AIDS Vaccine Initiative and Scripps Research recently announced results from an early stage trial showing their mRNA vaccine candidate, developed with Moderna, stimulated the production of rare immune cells that create bnAbs.

Their strategy, explained Schief, is to use a sequence of shots to try to gradually educate antibody producing B-cells. They also hope to train up another kind of white cell, known as T-cells, to kill any cells that still get infected despite the antibodies.

Efficacy trials are still a long way off, but he's hopeful the mRNA technology, which turn the body's cells into vaccine factories and has proven its worth against COVID-19, can make the difference.

© 2021 AFP

©2021 GPlusMedia Inc.

12 Comments
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Since the late 90's, according to multiple sources such as the NYTimes, AP, Forbes, and other reputable sites, one of the biggest profits on the books for many pharmaceutical companies are AIDS and HIV treatment drugs. That is one of the primary reasons why there isn't that much of a rush to create a vaccine. It would be reducing one of their biggest profit channels.

2 ( +7 / -5 )

Why cure a virus when you can treat it?

3 ( +5 / -2 )

That is one of the primary reasons why there isn't that much of a rush to create a vaccine. It would be reducing one of their biggest profit channels.

Except that the efforts to create a vaccine consume a lot of time, money and human resources in every country that has research capabilities for infectious diseases. Antiviral drugs are not a good source of profit since more than a decade ago when political pressure made companies release the patents for more than a dozen antiviral drugs that can be produced now as generics.

Also, if you think the main producers of studies are the pharmaceutical companies themselves you would be mistaken, hospitals, universities, research institutes are the driving force for most of the developments in antiviral therapies in the last few years, obviously governments benefit much more from cures than from treatments and many companies that hold no patents for antivirals are extremely happy to make consortiums with researchers on public institutions to test and refine better drugs, one cure, even if it is extra cheap would not reduce their profits (since they don't make any from the treatments) and may even pull them to the first class of pharmaceutical companies.

The reality is that the disease is not susceptible of control by the immune system as explained in the article, so anything that relies on it to finish the infection is bound to have only minor success, vaccines being the prototypical treatment that does that.

-2 ( +4 / -6 )

Because when you cure someone you stop any chance of transmission. It's like saying why cure polio?

I read somewhere (Sorry, I cannot recall) that being circumcised reduced the risk of becoming infected by about 70% which is a far greater efficacy rate than any of the vaccines so far tried.

0 ( +3 / -3 )

Because a HIV vaccine isn’t part of the narrative. Now, something like Covid-19, now that’s a different story

-3 ( +4 / -7 )

one of the biggest profits on the books for many pharmaceutical companies are AIDS and HIV treatment drugs. 

A number of HIV patients have realized that they didn't even need to take those drugs. They simply quite, and have been fine for years.

-5 ( +3 / -8 )

I read somewhere (Sorry, I cannot recall) that being circumcised reduced the risk of becoming infected by about 70%

The article below suggest there may be some benefit, but the overall risk reduction is put at 23%. Also, it seems the benefit applies mainly in low and middle income countries, which makes it a little difficult to interpret any cause and effect.

https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(18)30567-9/fulltext

4 ( +4 / -0 )

A number of HIV patients have realized that they didn't even need to take those drugs. They simply quite, and have been fine for years.

Um, no. No they have not. Even when the virus is suppressed to un-detectable levels, it is still in the body somewhere. If you stop taking the ARV meds, it begins to reproduce again and the patient will eventually develop AIDS and die.

This is a well known fact and it is what killed boxer Tommy Morrison.

4 ( +6 / -2 )

I don't remember the details, but I had the impression it had something to do with a PCR positive result not equaling infection.

-3 ( +2 / -5 )

Thank you for the informative article.

How do these companies know the success rate of their vaccine tests? Do they really have 2600 women in a poor place in Africa engage in risky behaviors in order to see how many of them do not become HIV positive? Or worse, have them engage in sexual relations with known infected persons? After all, an effective test would be to compare against real world conditions. Hopefully the vaccine works wonderfully. But if it doesn't, will Johnson & Johnson provide these now-HIV positive women free antiretroviral therapy the rest of their lives?

0 ( +1 / -1 )

I don't remember the details, but I had the impression it had something to do with a PCR positive result not equaling infection.

Then you need to remember better, because that is not true nor it is related to the reality of HIV integration into the genome. Why don't you search for the reference for your claim? reading it again can dispel your misunderstandings.

2 ( +4 / -2 )

This is a well known fact and it is what killed boxer Tommy Morrison.

There are claims that Morrison faked his blood tests, so I would take this with a very large pinch of salt. He may not even have been taking his meds.

0 ( +0 / -0 )

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