AIDS stands for ‘acquired immunodeficiency syndrome’ and describes the collection of symptoms and infections associated with acquired deficiency of the immune system. Infection with HIV has been established as the underlying cause of AIDS. The level of HIV in the body and the appearance of certain infections are used as indicators that HIV infection has progressed to AIDS.

While no one ever dies directly from AIDS, this disease leaves the body susceptible to attack by millions of antigens and other diseases, hungry for indefensible prey.

HIV infects and destroys T-cells, the basic building blocks of the immune system, by binding to special receptors on T-cells called CD-4. The virus cannot survive very long out of a cell and therefore can only pass from one person to another through direct contact of liquids. The virus most commonly spreads between partners during intercourse and from sharing needle tips.

How do you destroy a virus? Simply put: you can’t. Unlike bacteria, viruses hide within host cells and therefore cannot be targeted with conventional antibiotics. For the common cold virus, most people simply stay in bed and relax in order to help their immune system do its job. For stronger viruses, like rabies, the flu, and Hepatitis, vaccines are prescribed ahead of time in order to prepare the immune system for the virus.

To understand how vaccines work, it’s important to take a moment and learn the basics of the immune response. When a person gets infected with a virus, special types of cells called T-cells migrate towards the invaders and try binding to them. In order to bind to the invaders, however, a T-cell must have a specific receptor that matches the surface of the virus. It takes the body about two to three days to generate enough random T-cells of which one will be able to bind to the enemy. When a specific T-cell binds to the virus, it eats it up and deposits various parts of the virus on its surface. This triggers a rapid production of antibodies, which work with the T-cells to help destroy any last vestiges of the virus.

So why doesn’t the body destroy rabies, Hepatitis, and other viruses on its own? Why must we vaccinate? The answer lies in the 2-3 lagging period which it takes the body to develop its T-cell repertoire to do battle. During these days, the virus has the opportunity to grow and spread unchecked throughout the body causing widespread carnage and destruction. By the time the body knows what it has been infected with, it’s too late and the virus has already grown out of control. The theory of vaccination is that if the body were exposed to a weakened form of the virus ahead of time, then it would have ample warning to build up its T-cell “army’s” in order to battle the potential virus.

So what’s taking scientists so long to develop an AIDS vaccine? Why not take some HIV virus, weaken it until it’s practically dead and then inject it into people? This way, their bodies will be able to make T-cells against the virus before they ever get infected by the real thing?!

HIV, unlike other viruses, mutates at an alarming rate. For example, in any one individual infected with the virus there may be over twenty different versions of the virus. While each version maintains the ability to destroy the immune system, they differ slightly in their structure. Therefore, the body must make a different T-cell to combat each variant. Thus, in order for scientists to vaccinate people against AIDS they would have to make hundreds of different vaccines, each one using a different strain of the virus!

(from UNAIDS, & The Commentator – Science & Technology, Issue: 10/11/05)

1984: AIDS vaccine “in two years”
A vaccine for HIV, the virus that causes AIDS, will be available for clinical trials within two years, says Dr. Robert Gallo of the National Cancer Institute, and one of the scientists who first identified the HI virus.

1994: “Defiant microbe” baffles scientists
Despite dozens of clinical trials and plenty of false starts, scientists are unable to pin down a vaccine for HIV. The time line is so long and tedious because the virus is tricky and very good at out-smarting the human body’s defense mechanisms. It mutates at an alarming rate, which weakens the immune system’s response. By the time the body has produced an antibody against the virus’ proteins, the virus has already changed and the antibodies can no longer recognise them.
The virus can also induce the host to produce ineffective antibodies as well as make it difficult for the body to decipher between itself and the virus, which uses a sugar coating similar to self-proteins of the host.
“We are dealing with the nastiest possible virus that is scientifically incredibly smart. We are continually challenged. And it also challenges us on every political, social and cultural level in terms of the way the epidemic is spread,” says AIDS Vaccine Advocacy Coalition (AVAC) Executive Director Mitchell Warren.

2004: More than 40 million infected
AIDS has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics in recorded history, says the latest report from UNAIDS, the joint United Nations programme on HIV/AIDS.
Despite recent, improved access to antiretroviral treatment and care in many regions of the world, the AIDS epidemic claimed nearly three million lives in 2004; more than half a million were children.
The total number of people living with HIV reached its highest level of an estimated 40-million people, said UNAIDS. More than four million people were newly infected with the virus in 2004.
The harsh reality is that, despite all global efforts, the number of infections is continuing to rise around the world. While more than 70% of all people living with HIV are in sub-Saharan Africa, the biggest increases were recorded in East Asia, Eastern Europe and Central Asia. This was driven particularly by China’s growing epidemic.
Increasingly, women are become the victims of AIDS. More than half the global sufferers are now women – and in Africa, 76% of young people living with HIV are female.
One third of all AIDS deaths happen in Southern Africa. South Africa holds the dubious record of having the highest number of HIV positive people of any country in the world, with 6-million South Africans carrying the disease. Frighteningly, at least half do not know they are infected.
Asked about prospects for a cure, Professor Luc Perrin, head of Clinical Virology at Geneva University Hospital, replied: “Nothing is working and what is clear is that no vaccine is effective.”

2005: Early signs of hope
Scientists report cautious optimism in the 25-year struggle to identify a vaccine for AIDS.
“We certainly find reasons to be optimistic both because we are understanding more and more about what’s happening within the body and how this virus works,” says Mitchell Warren, Executive Director of the AIDS Vaccine Advocacy Coalition.
“And I think we ought to remind ourselves that although we don’t have a vaccine yet, every single trial – and there have been dozens and dozens of vaccine trials over the last decade – is advancing our scientific knowledge.”
Warren said annual funding for AIDS vaccine research has risen from $350 million to about $700 million. Nevertheless, many researchers say at least one billion dollars needs to be spent annually.
Importantly, a number of major drug firms have now committed themselves to the search for a vaccine. These include Merck, GlaxoSmithKline and Wyeth. “The fact that these massive companies are putting big resources behind the quest bodes well,” said Dr Ravi Sathay of the International AIDS Vaccine Initiative (IAVI).
AIDS activists also report a greater sense of collaboration and cooperation among the world’s scientists and researchers. One of the ways this is being done is through the Global HIV Vaccine Enterprise, a two year old effort to create a collaborative umbrella organization to share knowledge, and through the IAVI, which is concentrating on research in developing economies where AIDS prevalence is at its highest.
Dr. Larry Corey, head of the infectious disease program at Fred Hutchinson Cancer Research Center in Seattle, reports particular scientific interest in two of the approximately 30 trials currently taking place.
“The two leading candidates include one that’s manufactured by Merck that is in an efficacy trial now that will enroll 3,000 people in the United States, the Caribbean and South America. About 750 or 800 have been enrolled so far. We probably won’t have the results until the end of 2007,” says Dr Corey.
“There’s also another vaccine made by the Dale and Betty Bumpers Vaccine Research Center at the NIH and that has two components: it’s a DNA vaccine that’s then followed by an adenovirus vaccine [which uses a virus to deliver HIV genes directly to white blood cells to elicit a response]. That is in phase 2 trials, being tested in the United States, the Caribbean, East Africa and South Africa.”

2007: Breakthrough in South Africa, India
South African and Indian scientists working together on finding an AIDS cure today reported a critical breakthrough which they say will lead to the rapid development of one or more vaccines against the killer virus.
The team announced Phase III Efficacy Trials of two different forms of vaccines developed from the combination of four genes from the main HIV sub-types; one containing “naked” gene fragments of the HI virus (free, not incorporated into any DNA strands) that are incapable of becoming infectious; and the other a weakened adenovirus (a respiratory virus that often causes the common cold) to carry the gene fragments. The adenovirus can not replicate and therefore cannot cause a respiratory infection nor can it infect the patient with HIV.
These vaccines will introduce the viral proteins to the body, thus giving it a chance to induce an immune response when it recognizes them as foreign invaders. From this response, the body will develop what is called “immunologic memory” so that if the body were to be exposed to the virus again it would recognize and destroy it rapidly.
The concept is much like teaching a child the alphabet by showing them the letters until they learn how to pronounce each one. In this case, the vaccine is teaching the immune system to recognize the virus by exposing it to non-infectious components so that the body can identify it later and know to destroy the virus.
AIDS bodies are watching the developments with enormous interest. A vaccine for AIDS will result in savings worth billions of dollars for governments, and particularly for business, which in many parts of the world carries the main burden of providing antiretroviral treatment for staff and often their families and dependents as well.
Said a spokesman for Anglo American, one of the world’s largest mining groups and a massive employer of staff in developing countries: “The cost of treating AIDS is a huge burden on companies. A vaccine would release many billions of dollars for investment in other areas of business and society.”
But health authorities warn that while a vaccine will prevent new infections, it will still leave the world with more than 50 million HIV-positive people who will still need antiretroviral and other treatment.
“AIDS remains the most destructive pandemic the human race has ever witnessed,” said Dr Ravi Sathay of the International AIDS Vaccine Initiative (IAVI).

2008: Vaccine formula released
Formulae for two different AIDS vaccines are to be released for final health authority approval, and then for commercial development, following the completion of Phase III Efficacy Trials by a consortium of South African and Indian researchers.
This follows “unprecedented collaboration” between international AIDS bodies, spearheaded by the International AIDS Vaccine Initiative (IAVI).
IAVI spokesman Dr Ravi Sathay said that while South African and Indian researchers had led the project, they had been “richly supported” by many organizations such as the National Institute of Allergy and Infections Disease (NIAID, the US Military HIV Research Program and the Vaccine Research Center (VCR).
“We have shown the world that different nations can work together for the common good of mankind.”
The breakthrough by the South African and Indian scientists has nonetheless caught the major pharmaceutical manufacturers on their back feet. Several – including Merck, Wyeth and GlaxoSmithKline have been deeply involved in the search for an AIDS vaccine, and will now watch other drug companies benefit from what has been estimated to be a US$15 billion market.
Dr Sathay said formulae for two different vaccines would be released initially in the Indian and African markets by several pharmaceutical manufacturers which had committed extensive support to the research programme. But he warned that drug approval of the vaccines would still take between one and two years. He thus anticipated the first vaccines would be on the market only in 24 – 36 months.
“But we are calling on world leaders to put pressure on the health authorities to speed up the approval process, while still ensuring proper standards are maintained. The world cannot be made to wait any longer for an AIDS vaccine.
Dr Sathay pointed out that extensive human trials had been carried out over the past two years in both India and several African countries. “The initial testing has already been done under the strictest health conditions and has proved a success,” he said.

2009: Rival drugs launched
Three rival AIDS vaccines are ready for release onto the market, once drug authority approval has been received. This follows breakthrough discoveries by a consortium of South African and Indian researchers.
“These vaccines have the potential to eradicate HIV/AIDS within the next ten years or so,” said Dr Ravi Sathay of the International AIDS Vaccine Initiative, the non-profit body which coordinated the ground-breaking research.
Sathay cautioned, however, that this was an optimistic time frame as it would take massive effort to get the vaccine to the majority of infected individuals around the world. In addition, drug approval is expected to take up to 24 months.
“The dreadful reality of the AIDS pandemic is that the people who need treatment the most are in the least-developed regions of the world – and the least able to pay for treatment.”
Nonetheless, the release of the vaccines was an “incredible feat”, as HIV/AIDS is currently the fifth largest cause of contagious deaths.
“Three quarters of those who carry the disease live in sub-Saharan Africa and in Botswana, for example, 50 percent of all adults have HIV and three quarters of all children currently 15 years old will die of AIDS before they reach fifty years of age. This has slashed the average life expectancy in Botswana to a mere 36 years,” said Dr Sathay.
“The release of the vaccines will at least start the process of ending new infections, although we still live with the grim prospect of 60 million people already carrying the HIV virus,” he said.
Governments, NGOs and business bodies around the world have lauded the scientific breakthrough s one of the most important social and medical developments of the century.
“AIDS has killed more than 40 million people since 1981,” said a spokesman for UNAIDS. “The ability to prevent further infections is a massive breakthrough, and will enable us to focus additional resources, which would have been utilized in prevention campaigns, in helping the more than 60 million people who are now living with HIV.”
A spokesman for the Global Mining Council, which is one of the largest employees of staff in developing countries, said the release of the vaccines would release “billions of dollars” for investment in other areas. “Business has largely borne the brunt of the cost of this pandemic. It is now critical we get the vaccine onto the market as quickly as possible, and out to the people.”
He said the Global Mining Council was committed to rolling out the vaccine to staff and their dependents around the world. “The cost will continue to be high, but this is both the right thing to do, as well as good business sense.”