Vox reader Burak Ova asks: What is HIV and what is AIDS? How is it transmitted? What are the prevention methods? Is there a cure?Human immunodeficiency virus (HIV) killed millions of people every year in the early 2000s during the height of the AIDS pandemic. Now, some two decades later, scientific advancements and public health interventions have transformed one of the deadliest diseases into something manageable, where a regular dose of medication nearly prevents its spread altogether.So youre right to wonder whether weve squashed AIDS, at least to the point where people dont have to worry about it. HIV is a particularly tricky virus. When it infects a person, the virus infects and kills a specific type of blood cell (called a T cell) that fights infections. This weakens the immune system and also prevents the immune system from killing HIV. If left untreated, an HIV infection develops into a severe disease called acquired immunodeficiency syndrome (AIDS). At that point, the virus has completely destroyed the immune system this makes people more susceptible to a wide range of infections with little protection.Sign up for the Explain It to Me newsletterThe newsletter is part of Voxs Explain It to Me. Each week, we tackle a question from our audience and deliver a digestible explainer from one of our journalists. Have a question you want us to answer? Ask us here.HIV spreads through contaminated bodily fluids, usually during sex or when people share needles. Scientists now believe that HIV first spread to humans from infected chimpanzees in Cameroon in Central Africa. The virus spread slowly and sporadically among humans, finding its way to modern-day Kinshasa, the Democratic Republic of Congos bustling capital city. From there, the virus went global, and in 1981, the Centers for Disease Control and Prevention first documented several cases of what would come to be known as HIV. Since those fateful days, almost 90 million people around the world have been infected with HIV, and more than 40 million have died from the disease. At one point, almost 5 million people became infected with HIV each year, and some 2 million people died annually from it.Today, the outcomes are much better. In 2023, some 600,000 people died from HIV, while just over 1 million people were newly infected with the disease. Scientists and public health officials have developed a slew of medications and interventions to prevent infection or keep the virus so in check that HIV-positive people have no symptoms and can live full, healthy lives. Ending AIDS actually seems feasible. But, despite such incredible progress, HIV remains strong in much of the world. These tools have not been enough and will not be enough to end the epidemic once and for all alone. While more medical interventions, such as a true cure for HIV or a vaccine for the disease (which is likely still years, if not decades, away), would help, this is no longer really a problem of science. Ending the HIV epidemic has been plagued by trying to solve the seemingly insurmountable problem of equity and discrimination.In some places, especially African countries, HIV and complications from it remains one of the leading causes of death. Certain populations gay men, adolescent girls and young women, sex workers, people who use IV drugs, and people in prisons are at a disproportionately high risk of not only becoming infected with HIV but also not receiving adequate treatment.If this were just about developing products, doing the research and development, this epidemic would be over, said Mitchell Warren, the executive director of the international nonprofit AVAC. Its not unique to HIV, but HIV is probably the most glaring example. HIV is an epidemic that is obviously about a virus, but its spread because of inequity, because of stigma, because of discrimination, because of criminalizing behaviors. However, American and European support for the fight against HIV is waning. Governments are slashing critical funding and even considering eliminating key HIV programs such as PEPFAR, or the US Presidents Emergency Plan for AIDS Relief. But relenting now risks a resurgence of the disease that could threaten not only human lives but economic and political stability as it did when the epidemic first emerged.How far have or havent we come in ending HIV?Warren started his career in HIV in 1993. He was stationed in South Africa as the country was rapidly becoming the epicenter of the HIV epidemic. Patients with HIV wasted away in front of his eyes, he recalled. Roadsides were lined with coffin makers. Every weekend, Warrens colleagues occupied their time traveling from one funeral to the next. At the time, HIV was a death sentence, and the only preventative tool physicians and public health officials had at their disposal was the male condom, which prevents the virus from spreading during intercourse but does nothing to protect drug users or homosexual couples who often dont use condoms because they arent trying to prevent pregnancy. Condoms, of course, also do not prevent pregnant people from passing on the virus to their fetus, another way that HIV can be spread.In the first decade of the epidemic, drug companies created an antiretroviral therapy treatment that keeps the amount of virus in the body known as the viral load at such low levels that the virus couldnt be spread from person to person. While these treatments did help reduce the massive number of HIV deaths, they werent enough to end the epidemic because these early treatments required patients to take dozens of pills a day. (And they were given after someone already had HIV, so they werent preventative.) Even setting aside the sheer cost and numerous side effects of taking that many drugs so frequently, getting patients to take all those pills was a major challenge even in wealthy countries. In places like South Africa and other developing countries with too few medical centers and doctors, distributing and stocking enough drugs and getting them into patients hands was insurmountable. It wasnt until 2006 that pharmaceutical companies developed the one pill, once a day regimen to treat HIV-positive patients, which helped ease logistical and adherence challenges. Then, in 2012, the Food and Drug Administration approved pre-exposure prophylaxis, or PrEP, therapy, which allowed people without HIV to take medicines to prevent infection. Though PrEP is not a cheap option it can cost up to $2,000 per patient per month in the US HIV advocates hailed PrEP as a critical tool in the fight against HIV. Along the way, massive HIV programs like PEPFAR rolled out other campaigns and interventions such as promoting safe sex practices, encouraging male circumcision, and rolling out rapid HIV testing services to prevent the spread of HIV. But despite these amazing scientific achievements, HIV remains an enduring challenge not because of science but largely because of stigma, discrimination, and marginalization. While some 20 million people around the world today take HIV medication, about 20 percent of people with HIV cannot access treatment. Gay men, sex workers, and people who use IV drugs are all at higher risk of contracting HIV, but they are often hesitant to seek out testing or treatment because they fear doctors and nurses will treat them poorly, or worse, report them to authorities. Sex work is illegal in at least 100 countries, and IV drug use is illegal in all but about 30 countries. Even homosexuality remains criminalized in 64 countries, including about 30 of 54 African countries, where the HIV burden is highest. The legal challenges have made it difficult for public health officials to implement certain interventions even when we know they work. Giving clean needles to IV drug users, for example, reduces the spread of HIV among drug users and yet is rarely, and even then controversially, implemented in very few countries.Then there is the challenge of gender equality. Adolescent girls and young women are also at a particularly high risk of contracting HIV, especially in certain parts of the world. In 2023, 62 percent of all new HIV infections in sub-Saharan Africa were among girls and young women. In some parts of these countries, young girls, who lack the agency to insist on safe sex practices, are married to older men who have multiple sexual partners, which increases the risk of HIV transmission. Rape is unfortunately common in regions afflicted by conflict. In other situations, especially in refugee camps or places with limited economic opportunities, girls and women are forced to turn to sex work to survive.We tend to see HIV finding the fault lines in society, Warren explained. This is a virus that is spread by sex and by drug use. Those are two behaviors that have been stigmatized and criminalized not just during 40 years of HIV, but for hundreds and thousands of years.RelatedHow likely is it that we can make more progress against HIV/AIDS?Bridging cultural and logistical divides is what makes public health so challenging. Ive worked in global health for almost 10 years, and I know that achieving public health goals, such as eliminating HIV, isnt simply about inventing and rolling out medicines and interventions but about changing societal practices and cultural beliefs. But short of solving the persistent global challenges of inequality and discrimination, we can do more to ensure people around the world continue to have access to preventative care, testing services, and treatment. To do that, we need money a lot of it. For the past decade, the US government has donated more than $5 billion a year to the global fight against HIV; about half of those funds are routed through PEPFAR. Historically, PEPFAR has enjoyed bipartisan support, but in recent years, politicians particularly from the right have threatened to end or dramatically reduce global health funding to focus on bolstering domestic spending and improving the lives of Americans. Other politicians want to end PEPFAR because some funds are spent to improve and expand access to sexual and reproductive care. HIV is, after all, spread through sex. But the proximity of HIV care to abortion services is too close for many Republican politicians, meaning that, in this rising tide of anti-abortion views, the US government should also end funding for HIV. The fight against HIV is losing momentum around the world. Globally, funding for HIV dropped by about 8 percent from $21.5 billion in 2020 to $19.8 billion in 2023, according to the Joint United Nations Programme on HIV/AIDS, or UNAIDS. Between 2022 and 2023, the US and other major donor countries, including the European Commission, reduced their global funding for HIV and seem poised to further cut funding for global health more broadly. The future may be even more bleak: President Donald Trump announced on Tuesday that the US was cutting ties with the World Health Organization, the UNs health agency that plays a key role in providing HIV treatment and care to millions of people, particularly those in low- and middle-income countries.The simple fact is that if global funds for HIV are reduced, we will see a rise in HIV cases and deaths. The global community has accomplished so much, but the fight is not over.This story was featured in the Explain It to Me newsletter. Sign up here. For more from Explain It to Me, check out the podcast.Youve read 1 article in the last monthHere at Vox, we're unwavering in our commitment to covering the issues that matter most to you threats to democracy, immigration, reproductive rights, the environment, and the rising polarization across this country.Our mission is to provide clear, accessible journalism that empowers you to stay informed and engaged in shaping our world. 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