The sequence of stages that HIV undergoes within a human body.
In 1987, the world witnessed a significant breakthrough in the fight against HIV with the approval of zidovudine (AZT), a treatment that targets the virus in its third stage of replication – the conversion of viral RNA into DNA [1]. Today, the World Health Organization estimates that around 38 million people are living with HIV, underscoring the ongoing need for effective treatments [2].
HIV, a virus that primarily attacks the immune system, follows a complex life cycle consisting of seven key stages: viral entry into host CD4+ T cells, reverse transcription of viral RNA into DNA, integration of viral DNA into the host genome, transcription and translation of viral proteins, assembly of new viral particles, and budding/release from the host cell to infect others [3].
Current treatments, known as antiretroviral therapy (ART), aim to disrupt the HIV life cycle at various points to prevent viral replication and disease progression. These treatments include entry inhibitors, reverse transcriptase inhibitors, integrase strand transfer inhibitors, and protease inhibitors [4].
Entry inhibitors block HIV from binding and fusing with CD4 cells, preventing entry. Reverse transcriptase inhibitors (NRTIs and NNRTIs) hinder the conversion of RNA to DNA, halting replication early. Integrase strand transfer inhibitors prevent the integration of viral DNA into host DNA, while protease inhibitors block the maturation of new viruses, keeping them noninfectious [4].
By combining drugs acting at these multiple stages, ART decreases HIV viral load, preserves immune function (CD4 cells), and prevents progression to AIDS [5]. It is crucial to maintain continuous adherence to ART to maintain viral suppression and reduce drug resistance [2]. Modern regimens often include two or three drugs targeting these different stages for effective lifelong treatment [2].
Prompt testing and care after exposure are essential, as HIV treatments can slow the progression of the virus to AIDS but do not halt it entirely. The virus progresses through three stages: Acute infection, Chronic infection (or the asymptomatic or latent HIV stage), and AIDS [6]. During the acute infection stage, HIV is infiltrating the body and invading CD4 cells, with high levels of the virus in the blood, posing a high risk of transmission [7].
The chronic infection stage can last for years without any symptoms, while AIDS is the final stage, characterized by a weakened immune system and susceptibility to opportunistic infections. People with AIDS have high levels of the virus in their blood and bodily fluids, making it extremely transmissible [6].
Medical advances and a better understanding of the life cycle of HIV have led to the availability of medications that can inhibit viral replication, significantly reducing the risk of transmission with effective treatment. With HAART therapy, a person's viral load can be reduced to undetectable levels [8].
However, it is possible to pass HIV on to others if a person is not receiving or correctly taking this medication. HIV is an enveloped virus with an outer lipid membrane, glycoproteins, a matrix protein layer, and an internal capsule called the capsid, containing two strands of ribonucleic acid (RNA) and enzymes such as reverse transcriptase, integrase, and protease [9].
In conclusion, the HIV life cycle involves entry, reverse transcription, integration, transcription/translation, assembly, and release, with current treatments primarily disrupting the cycle at entry, reverse transcription, integration, and protease-mediated maturation stages to stop viral replication and disease progression. With continued research and advancements in HIV treatment, we can hope for a future where HIV is no longer a life-long illness.
References: [1] https://www.ncbi.nlm.nih.gov/books/NBK234882/ [2] https://www.who.int/news-room/fact-sheets/detail/hiv-disease-epidemic [3] https://www.aidsmap.com/hiv-basics/hiv-replication [4] https://www.aidsmap.com/hiv-basics/antiretroviral-treatment [5] https://www.who.int/publications/i/item/9789240023925 [6] https://www.cdc.gov/hiv/basics/livingwithhiv/stages.html [7] https://www.cdc.gov/hiv/basics/livingwithhiv/acute-hiv-infection.html [8] https://www.cdc.gov/hiv/basics/livingwithhiv/managing-hiv-disease/understanding-undetectable-viral-load.html [9] https://www.ncbi.nlm.nih.gov/books/NBK234882/
HIV primarily attacks the immune system, making it a significant medical-condition in health-and-wellness. The virus follows a complex life cycle, involving seven stages, one of which is reverse transcription of viral RNA into DNA, a stage that current treatments, such as reverse transcriptase inhibitors, aim to disrupt [3, 4]. Regular treatment and maintained adherence to these medications can help preserve health by reducing viral load and preventing progression to health-related conditions like AIDS [5]. Thanks to advancements in HIV science, effective treatments have been developed to target various stages of the virus' life cycle, reducing the risk of transmission [8].
