Human immunodeficiency virus (HIV) is a lentivirus (slowly replicating retrovirus) that causes the acquired immunodeficiency syndrome. Since it’s identification in 1981, it has come to be identified as one of the most potent infectious diseases in the world.

 

HIV continues to be a serious problem for people all over the world. 2.1 million new cases of HIV in 2015 were reported worldwide. An estimated 36.7 million people are living with HIV around the world, and, as of June 2016, 17 million people diagnosed with HIV were on medication to treat HIV, called antiretroviral therapy. In 2015 alone it has been reported that around 1.1 million people lost their lives to AIDS or illnesses attributed to AIDS. Sub-Saharan Africa and accounts for more than 60% of all new HIV infections. High rates are also found in Asia and the Pacific, Latin America and the Caribbean, and Eastern Europe and Central Asia.

 

The HIV virus was identified in 1981, and yet after 3 decades there is still no cure for it. What makes the disease so complex? And how much do we know about the virus?

 

There are two main strains of HIV that are responsible for the infection and associated diseases. These are: HIV-1 and HIV-2. HIV-1 is distributed all over the world while HIV-2 is primarily found to be responsible for infections in West Africa and in Southern/Western India and Korea. HIV-1 further has 3 more strains, which genetic make up is different.

 

Spread and Lifecycle of HIV:

 

HIV-1 spreads through unprotected sexual intercourse, blood-blood contact, or from mother to child during pregnancy, childbirth and breastfeeding. Once the virus binds to the cell membrane of immune cells it proceeds to release its RNA. Being a virus HIV is composed mostly of RNA, which post the binding of the HIV to the human cell needs to be converted to DNA in order to be assimilated into the host cell as DNA is responsible for replication in humans. The viral RNA is then converted to DNA, the basis of the host cell (Human cell). The virus DNA gets then integrated into the host cell DNA. Having become part of the host cell, the virus proceeds to use the host cell to replicate itself, hoodwinking the body into not being able to differentiate between the virus and the immune cells. Making it susceptible to attacks from microorganisms like bacteria and other viruses.

Current available treatments:

 

ART remains the gold standard for the control of the disease. However, the major problem with ART remains that the circulating virus are controlled but it is not able to affect the genetic material incorporated into the host cell. ART controls the disease but does not eliminate it completely.

 

Vaccination could potentially hold the key to dealing with the threat of AIDS. Vaccination would not only ensure the eradication of the disease but could also circumvent some of the present day prevention options.

 

Until recently one of the major reasons for not focusing on vaccines was the instability of RNA based vaccines.RNA (messenger) based vaccines have exhibited great therapeutic potential.

 

In a first of its kind study done on non-human primates (genetically closest to humans) it was reported that a relatively low dose (50 µg) of and RNA (messenger) vaccine, was safe and produced encouraging results. This is a big improvement on DNA based vaccines reported in earlier studies which required milligram doses (1000 fold higher) and were not as effective .

 

Another study found an oral drug it is reported to work by preventing the replication of the HIV virus thus potentially eliminating the disease. It also does not inhibit any other RNA processes. It is the only RNA based oral therapeutic to reach phase II.

 

The Bill and Melinda Gates will be investing $140 million in implantable devices that are the size of a matchstick in an effort to prevent the spread of HIV in Sub-Saharan Africa. The instrument is designed to aid in the preventive stage of HIV and will be able to hold between 6 to 12 months of therapeutic payload. It will be able to deliver just the right amount of medicine to patients to ensure they are up to date with their treatments.

 

Given the complex nature of the disease and its associated complications, the eventual cure (which will come) will probably be a combination of ART, RNA vaccines, RNA based drugs and/or stem cell and gene therapy.