Summary
This article provides an overview of HIV, including its symptoms, transmission, treatment, and prevention. It also discusses the challenges of developing a vaccine for HIV, including the virus's ability to mutate and evade the immune response. HIV is spread through body fluids and can be transmitted through sexual intercourse, blood transfusions, sharing needles, and from mother to child during childbirth and breastfeeding. Antiretroviral medication is the main treatment for HIV, and prevention includes safe sex practices and proper needle hygiene. There are currently no available vaccines for HIV due to the virus's ability to mutate and evade the immune response.
Background
On June 5, 1981, (PCP). Opportunistic infections don’t happen in otherwise healthy people, so this report stood out because the five young men struck with PCP had been healthy up until the infection. This was the beginning of the recognition of a condition that would eventually be named Acquired Immune Deficiency Syndrome (AIDS). After several years of epidemiological investigations drawing from many branches of science, the Human Immunodeficiency Virus (HIV) was recognized as the cause of AIDS. The race for a vaccine started then, and has been going for more than four decades without a breakthrough. This article covers HIV infection and why it has been difficult to develop a vaccine against it.
Symptoms and Causative Agent
Initial symptoms of HIV infection are similar to symptoms from influenza: fever, sore throat, muscle aches, chills, fatigue. These happen 2 to 4 weeks after infection, and may last days to weeks. These initial symptoms then resolve, and the infection lays dormant in terms of symptoms for months to years. All the while, the virus is working to destroy the immune system.
The Human Immunodeficiency Virus is a “.” Non-retroviruses enter the host cell and use the cell’s protein-making machinery to multiply. Those viruses can be DNA viruses, where their DNA is integrated into the host cell’s DNA. Or they can be RNA viruses, where the cell reads the RNA itself to create viral proteins. HIV is different. It is an RNA virus that , and the DNA is then integrated into the host cell.
After months or years of HIV destroying the immune cells it infects, infections — opportunistic or otherwise — begin to become common. Several infections and the diseases they trigger are known as “.” A person with any of those illnesses, along with a positive test for HIV infection, is said to have AIDS. For those with access to antiretroviral medication, AIDS is no longer a terminal condition. For them, it is considered a chronic condition, something they can and will live with for an extended period. Unfortunately, access to such medications is not universal, and HIV/AIDS remains .
Transmission
, “HIV is spread from the body fluids of an infected person, including blood, breast milk, semen and vaginal fluids.” However, casual contact with these is not the biggest risk. The biggest risk comes from contact during sexual intercourse, blood transfusions, sharing needles for drug use, accidental exposures in healthcare or caring for people infected with HIV, and from mother to child during childbirth and breastfeeding. Everyone is at risk of infection, while some groups have a higher risk of infection due to their work or interactions with people infected with HIV. Use of pre-exposure prophylaxis with antiretroviral medication by those at high risk of infection, and proper treatment with antiretroviral infection, lowers the level of virus in the blood. .
Treatment, Care, and Prevention
The main treatment for HIV infection is . This medication stops the virus from infecting healthy cells, and/or prevents the virus from multiplying within the host cells. Proper use of antiretrovirals maintains the immune system healthy, preventing opportunistic infections. Misuse of antiretrovirals may lead to resistance, .
For individuals without access to antiretroviral medication, treatment involves the prevention and management of opportunistic infections. , since contracting a disease like measles could be deadly to a person with AIDS.
of HIV infection includes safe sex practices, screening of the blood supply, proper disinfection of needles re-used, proper disposal of needles and other sharps, and screening pregnant people for infection to mitigate risk to the fetus before, during, and after birth.
Complications
As stated above, the most serious complications from HIV infection come from the opportunistic infections a person may develop if the virus is allowed to multiply uncontrollably. These infections include fungal and parasitic infections that could be difficult to treat if the immune system is not functioning. Also, treatment for some opportunistic infections is costly or difficult to access, making AIDS a significant burden on the cost of healthcare in developing nations or in marginalized groups with low access to care within developed nations.
Available Vaccines and Vaccination Campaigns
As of June 2023, there are no available vaccines against HIV/AIDS. The reasons for this are many. First, the virus multiplies at a rate that makes mutations common. These mutations allow the virus to evade the immune response. The virus also encapsulates itself with some of the host cell’s membrane, making the virus “look” like it is part of the host instead of an invasive virus.
Much research has gone into an HIV vaccine, however. A search of in August 2023 shows 35 human clinical trials actively recruiting or about to recruit participants, along with 161 completed trials. On World AIDS Day in 2023, we interviewed on why it is so difficult to develop a vaccine. You can see that interview here:
Resources and Additional Readings
- CDC. Pneumocystis pneumonia --- Los Angeles. MMWR 1981;30:250--2.
- Get tested for HIV (CDC): https://www.cdc.gov/hiv/basics/hiv-testing/finding-tests.html
- World Health Organization, HIV and AIDS: https://www.who.int/news-room/fact-sheets/detail/hiv-aids