“World AIDS Day is an opportunity for every community and each individual to honor the [tens of millions of] people who have died worldwide from AIDS-related illness.”
- Centers for Disease Control and Prevention
“It is possible to end AIDS by 2030 if countries demonstrate the political will to invest in prevention and treatment and adopt non-discriminatory laws.”
- Joint United Nations Program on HIV/AIDS
On June 5, 1981, the Centers for Disease Control, now the Centers for Disease Control and Prevention (CDC), reported an unusual form of pneumonia, Pneumocystis carinii (PCP), in five young men, “all active homosexuals.” This was the outset of the HIV/AIDS pandemic. At that time, no one could have predicted that within a little over four decades (by the end of 2022) 85.6 million people would become infected with HIV, 40.4 million of whom would die from AIDS.
On December 1, 1988, the World Health Organization (WHO) initiated World AIDS Day in an effort to unite people in the fight against HIV, the virus that causes AIDS. Since then, World AIDS Day is commemorated on the first of December every year. As we just observed another World AIDS Day, I thought it a good time to briefly review the history of this devastating pandemic and to discuss the WHO’s and the CDC’s aspirational goal of ending HIV/AIDS by 2030.
History of HIV/AIDS. As I began my infectious diseases career in 1977, I witnessed the many ups and downs in the fight against HIV/AIDS. Obviously, it’s impossible within the confines of a Germ Gems post to do justice to all the salient aspects of this incredibly cruel disease or to cover all of the truly remarkable scientific breakthroughs. Nonetheless, here are what I consider to be just a select few of the most memorable developments.
Recognition of the HIV/AIDS high risk groups. Within the first year of the pandemic, it was already clear that sexual activity, especially men having sex with men, and injection drug use were high risk behaviors. And it was speculated that a virus, transmitted via either sexual activity or blood, was the cause of AIDS.
In 1984, researchers made the monumental discovery (Nobel Prize-worthy) establishing that HIV, a newly recognized retrovirus, was the cause of AIDS. By that time, Africa had become the epicenter of the pandemic, and women were at as great a risk as men. During these early years of the pandemic, stigma was (and still is) a horrific issue faced by HIV/AIDS patients.
Target of HIV. Early on, researchers discovered that CD4 lymphocytes (CD4 cells) are the primary target of HIV. (CD4 cells play a pivotal role in cell-mediated immunity by activating other immune cells called macrophages.) When a patient’s CD4 lymphocyte count falls below 500, the patient is at risk of a long list of opportunistic infections (PCP for example) and certain types of cancer. This discovery explained the pathophysiology of AIDS. Once this became established, strategies were developed to protect patients against these intracellular opportunistic microbes.
Treatment of HIV infection. By the end of the 1980s, assays for the level of HIV in the blood (“the viral load”) and of CD4 lymphocyte counts became major tools to assess the efficacy of antiviral drug treatment. In 1988, zidovudine (AZT) –a reverse transcriptase inhibitor—became the first drug shown to be effective in treatment of HIV infection. It was also shown to prevent pregnant mothers from passing HIV to their unborn fetuses.
Scientists and clinicians heralded the treatment of HIV with AZT. Yet, virtually all HIV-infected people still died of their infection. This was because of the wily nature of HIV. As an RNA virus, HIV quickly developed drug resistance. To counter this maneuver by the virus, researchers introduced combinations of antiretroviral drugs that targeted different components of HIV. “Highly active antiretroviral therapy” or HAART was the first of these drug combinations to be used.
In 1996, researchers showed that HAART greatly expanded the life span of people with AIDS. The advent of HAART represented a tremendous turning point in the HIV/AIDS pandemic. When put on this regimen, patients who were close to dying literally got up from their death beds and resumed a relatively normal life expectancy.
To date, the U.S. Food and Drug Administration has approved 32 different antiretroviral drugs. Physicians who specialize in HIV/AIDS management select which of these drugs to prescribe for individual patients. Their decision is based on assessment of viral resistance, the viral load, and CD4 lymphocyte count.
U.S. President’s Emergency Plan for AIDS Relief (PEPFAR). In 2003, President George W. Bush implemented PEPFAR—a U.S. governmental program to address the HIV/AIDS pandemic globally and help save the lives of those suffering from AIDS. This was an extraordinary development in HIV treatment. It is the largest commitment in history by any nation to address a single disease. To date, PEPFAR has saved more than 25 million lives and prevented millions of HIV infections. (This game-changing HIV/AIDS program is now in jeopardy of losing its funding due, in large part, to U.S. abortion politics.)
Prevention. To date, three HIV patients have been cured. All three received stem cell transplants from donors who carried a mutation that conferred resistance to HIV. This is, however, an impractical solution. Therefore, at present, the goal of HIV treatment is not to cure the infection, but to reduce the viral load in a patient to prevent transmission of the virus.
Researchers have shown that people living with HIV who maintain low levels of the virus in their blood have almost zero risk of transmitting it through sexual activity. Recognition that sustained undetectable levels of virus equals untransmissible virus led to the development of successful “Undetectable=Untransmittable HIV campaigns,” commonly referred to as “U=U” campaigns.
Antiretroviral therapy allows a patient with HIV to reach and maintain an undetectable viral load if the patient takes their HIV medication exactly as prescribed. Long-acting injectable antiretroviral drugs are also now available that can improve medication adherence in patients who struggle with regularly taking daily pills. One such drug, cabotegravir (Cabenuva), received FDA approval in 2020. It’s administered intramuscularly in the buttocks monthly or every two months.
Pre-exposure prophylaxis (PrEP) is another successful strategy for preventing sexually acquired HIV in the first place. (Like condoms, PrEP protects against picking up HIV, but unlike a condom, PrEP does not protect against other sexually transmitted infections. So practicing safe sex remains essential.)
Many people who practice PrEP prefer long-acting injectable drugs such as cabotegravir over daily pills such as Truvada and Descovy, the most commonly used drugs.
Unfortunately, a vaccine to prevent HIV—the ultimate goal— has yet to materialize. This isn’t for lack of trying. Almost every scientist (immunologist, microbiologist, virologist, etc.) working on HIV has thought hard about this challenge, and, in many cases, launched randomized control trials. There have been more than 250 HIV vaccine trials, most of them early stage, looking at safety. But there have been few vaccine trials—10 or so— that have advanced to the point of looking at efficacy.
The fundamental challenge of developing a vaccine against HIV is related to the biology of this retrovirus; it resides within the very type of cell that is pivotal for vaccine-induced memory (CD4 lymphocytes). Plus, HIV is an astonishing master at developing mutations that subvert the immune response.
Despite the dismal track record of HIV vaccine development to date, some researchers are cautiously optimistic that an ongoing trial, called PrEPVacc, will offer protection to prevent the spread of HIV (See the August 27, 2023 CNN report,“A trial is underway that could be the ‘last roll of the dice’ for an HIV vaccine this decade.”)
Can the HIV/AIDS pandemic be stopped by 2030? On December 1, 2022, the Journal of American Medical Association published the viewpoint article, “Ending the HIV Epidemic: We Have the Tools, Do We Have the Will?” In it, Dr. Marwan Haddad and his public health colleagues make the case that “evidence-based tools and interventions that can end the HIV epidemic are available, but success is incumbent on navigating an environment that has become increasingly hostile and politicized.”
Concerns about the social and political determinants of health also weigh heavily in the minds of leaders at the United Nations AIDS program. On November 29, 2023, they reported that the global response to AIDS is under threat because of an unprecedented backlash against human rights that is stigmatizing the groups at highest risk of HIV infection.
Based on the absolutely astonishing scientific and clinical breakthroughs in the past 42 years, it is my personal opinion that if an effective HIV vaccine is developed, we would certainly have a good “shot” at ending the HIV/AIDS pandemic by 2030. But it’s essential that politics, prejudice and personal opinion don’t get in the way of achieving that goal.
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