HIV and AIDS pandemic
By GELINDE NAREKINE
THERE is little argument that science has contributed greatly to our understanding of the external world. And so great that knowledge acquired by scientific means is considered more likely to be true than other forms of knowledge. Subsequently, medical science has contributed immensely to our recognition of microorganisms and their roles in a large number of infectious diseases, and in the discovery of antibiotics and vaccines for the treatment and prevention of infections, respectively.
In spite of the success of the last two centuries, we have carried into the 21st century, a challenge that has so far defeated the best that medical science has to offer. Acquired Immune Deficiency Syndrome (AIDS), has no definitive treatment, neither a vaccine, nor a cure, and not even an agreement as to how the Human Immunodeficiency Virus (HIV), slowly but progressively destroys the very essence of our survival, our immune system. Consequently, AIDS has emerged as one of the most extraordinary medical conditions in human history.
The Acquired Immune Deficiency Syndrome was first described in 1981. Its causative agent was then isolated and identified in 1983 through a collaborative effort by scientists in the US and France, naming it the Human Immunodeficiency Virus. There are so far two types, designated HIV-type 1 (HIV-1), which is responsible for most cases world-wide, and the related HIV-type 2 (HIV-2), producing an almost identical but milder illness, perhaps with a longer timeframe from initial infection to onset of AIDS.
Based on three independent transmission events that occurred early in the 20th century, HIV-1 was divided into three groups and named Group M, Group O, and Group N. Group M comprises most of the HIV-1 strains (variants) responsible for the worldwide AIDS pandemic, and further divided into nine subtypes. Transformational changes (mutation) in their genetic makeup and recombination events between these subtypes have resulted in numerous circulating recombinant forms (CRFs) and a number of unique recombinant forms (URFs). Unlike other human viruses, with HIV, we are dealing with a whole household of viruses, and all these different strains play a role in the global HIV/AIDS burden.
In 1986, the World Health Organisation estimated that there were 100,000 AIDS cases and 5-10 million HIV-infected people worldwide. It was projected that the annual number of deaths due to AIDS would peak in 2006 at 1.7 million. Instead, by end of 2001, over 24.8 million people were reported to have died from AIDS. By then, AIDS was already recognized as a global crisis. In 2020, it was revealed that more than 32 million people have died from AIDS-related illnesses since 1981. Today, there are about 38 million people living with HIV in the world.
The first case of HIV infection in Papua New Guinea was reported in 1986. Out of ten people whose blood samples were initially positive when tested by our national reference laboratory, a male expatriate was confirmed positive after his blood sample was retested in Australia. By the end of 1987, six people were confirmed HIV positive. The early infections were recognized in expatriate men, or in PNG citizens, male and female who had had sexual contact with infected expatriates. However, it soon became clear that transmission was also occurring between Papua New Guineans.
During the first ten years, the total number of HIV positive cases reached 1,330. By the end of September 2001, Papua New Guinea registered 4,415 confirmed HIV positive cases and 1,336 cases of AIDS. In 2020 it was reported that an estimated 45,000 to 51,000 people were living with HIV infection since detection of the first case in 1986. Of this, about 32,000 are currently on antiretroviral therapy (ART).
The Acquired Immune Deficiency Syndrome has become one of the top four causes of death globally, and to a certain extent, remains the world’s biggest healthcare problem. In areas of high HIV/AIDS prevalence, there is recurring burden on limited health and other resources, individual lives devastated, and family units disintegrated. With these, HIV continues to mock at us in every infected individual it irreversibly claims, with AIDS and death as end-results.
The Human Immunodeficiency Virus is surprisingly a small and simple virus. And so researchers know a great deal about the way it is contracted, makes its way through the body destroying the immune cells, and eventually cause AIDS. In spite of that, HIV has a complexity that still baffles the scientific community.
Mysteriously, HIV is implicated with nothing less than the two most important areas that are very central to human life and survival, our sexuality and the immune system. The virus is predominantly transmitted through sexual activities, and when in the body, it attaches to, attacks, and destroys the most important cell of the immune system called the CD4 T-cell. And so, it is not a surprise that governments and private individuals have spent trillions of dollars on efforts to find effective treatments, vaccines, and a cure for HIV/AIDS for the last 40 years. Unfortunately, the hope of an end to infection by bringing the virus fully under control remains elusive.
The discovery of a cure for HIV/AIDS is notoriously difﬁcult for reasons related to both science and approach. The mechanism of the virus in the body makes it difﬁcult to cure. HIV invades and then takes absolute control of the most important immune cell, the CD4 T-cell, which is responsible for defeating it. In the process, these immune cells are broken up and destroyed, and this reduces the number of functional CD4 T-cells. Without the protection of the CD4 T-cells, the infected person is vulnerable and will likely contract an opportunistic infection or an unchecked form of cancer that results in AIDS and, death.
In addition, HIV evolves at one of the highest recorded biological mutation rate known to science. Since it changes its genetic makeup so fast, it is impossible to treat with a single drug. These rapid changes in the viral genetic makeup is a major contributing factor in the failure of the immune system to eradicate the virus. Developing a single vaccine able to eradicate over 60 dominant strains, as well as a multitude of recombinant strains, becomes all the more challenging. Thus, conventional vaccines can only protect against a limited number of viral strains. The combination of the infection process and its rate of mutation make finding cure for HIV exceedingly difﬁcult.
Moreover, not all HIV-infected cells are active simultaneously. During the very early stages of infection, some of the infected cells do not produce new copies of the virus. As a result, resting viral particles can hide in the lymph nodes and other locations for months or even years, where it escapes detection by the immune system. Current antiretroviral drugs are unable to eliminate these HIV-infected cells because they are not circulating in the blood. Since these cells can become active at any time, it is certainly a problem for the person infected with HIV.
There are also disagreement in approach relating to the questions of what constitutes a cure for HIV/AIDS. Is it a sterilized cure in which no trace of the disease remains is the best approach? Is it a functional cure in which the disease is present but not capable of being transmitted and/or progressing to AIDS? Is controlling infection through the use of ARTs a cure if it calls for the daily medication with a cocktail of toxic drugs? Because each of the conflicting definitions and options will certainly require funding and technical know-how, the pursuit of addressing several would be exhaustive before we get anywhere in our quest to find a cure for HIV.
While antiretroviral drugs are not a cure, this cocktail of drugs halts the progress of HIV infection to AIDS by targeting HIV at a different stages in its replication cycle. Essentially, antiretroviral drugs have changed what was formerly a ‘death sentence to a life sentence’. As a result, those with HIV continue to live near-normal lives, with the caution that they must take medication on a regular basis while living with uncertainty over reemergence or a flashover of viral situation. It is true that the use of antiretroviral drugs have slowed the spread of HIV infection and reduced the number of deaths, there are still millions of people living with the infection in the world today.
Over those many years, the global efforts against HIV/AIDS, especially, that of the development of HIV vaccine, has been marked by numerous setbacks and disappointments. Each apparent breakthrough is presented with even more challenges and obstacles to overcome. Oftentimes, it seems that for one step taken forward, an unforeseen obstacle sets researchers back by even two steps. In the process, it is a fair assessment that the scientific community has made enormous progress in gaining greater insight into the complex dynamics of HIV infection and the body’s response to such infection. And yet, despite all of that, our hope of seeing a viable vaccine candidate and therefore, a cure for HIV/AIDS, still hangs in the balance.
With the overwhelming impact of the current viral pandemic, it is just as important that the global community has its focus on addressing SARS-CoV-2 and COVID-19. As a result, it is also likely that HIV/AIDS pandemic has been given a backstage approach. But the reality stares boldly at all of us. That the Human Immunodeficiency Virus is an undeniable fact, and is still being transmitted wherever and whenever humans move and live. It is persistently being spread between and within people, not so visible but unforgiving in its wrath, more or less, ‘a fire without smoke’. It continues to infect ten people, with six dying every minute – quite a number by any standard – making HIV/AIDS one of the greatest public health threats the world has known.
It took scientists less than a year to develop and deliver for use, not one, but several vaccines for SARS-CoV-2 and COVID-19. For about 40 years, scientists have been trying, but to date, they are not even any closer to finding a cure for HIV/AIDS. Or what about, at least, a vaccine? For the scientific community, this is still a complicated jigsaw puzzle, and for governments and individuals, both rich and poor, it is a dilemma with no easy answers – may be, for another 40 or more years.
Source of information:
1. American Gene Technologies 2016, Why is it so difficult to find an HIV cure?, viewed 05 December 2021, http://www.americangene.com
2. Global AIDS Monitoring 2020, Country Progress Report – Papua New Guinea, viewed 07 December 2021, http://www.unaids.org>files>documents
3. Myhre, J and Sifris, D 2021, Why is it so hard to make an HIV vaccine? Very Well Health, viewed 05 December 2021, http://www.verywellhealth.com
4. Narekine, G 2003, Seroepidemiology of HIV-2 in Papua New Guinea: a retro-prospective study, BMedSc Thesis (unpublished), School of Medicine & Health Sciences, UPNG
- Gelinde Narekine is a
technical officer in the discipline of Medical Laboratory Science, School of Medicine & Health Sciences, UPNG.
UNAIDS 2020 estimates of the total number of people now living with HIV infection
in the world, thus, a relatively true representation of the global HIV/AIDS pandemic.