Question
What is the difference between HIV-1 and HIV-2?
27 September 2006. Related: All topics, Other tests.
What is the difference between HIV1 and HIV2 with regards to structure, function, occurence and survival in the environment?
Answer
HIV-1 and HIV-2 are two different viruses. HIV-1 is the main family of HIV and accounts for 95% of all infections worldwide. HIV-2 is mainly seen in a few West African countries. The spread in the rest of the world is negligible.
Although HIV-2 generally progresses more slowly than HIV-1, some HIV drugs (NNRTIs like nevirapine and efavirenz) do not work against HIV-2.
On a structural level HIV-1 and HIV-2 have important genetic differences. A technical description of the difference is that the vpu gene found in HIV-1 is replaced by the vpx gene in HIV-2. In addition, the protease enzymes from the two viruses, which are aspartic acid proteases and have been found to be essential for maturation of the infectious particle, share about 50% sequence identity.
There are, however, differences in substrate and inhibitor binding between these enzymes. Most notably between the CGP 53820 inhibitory binding.
On functional level, there is a difference between the two viruses in terms of how easy it is for the virus to infect someone. HIV-1 enters the immune system by attaching onto the CD4+ receptor found on the surface of certain white blood cells. HIV-2 has a harder time gaining such a foothold.
So HIV-2 generally progresses much more slowly, with lower viral laod and slower risk of becoming sick. However, some HIV drugs (including NNRTIs) are not active against HIV-2.
Both viruses are fragile and highly susceptible to physical and chemical agents and therefore do not survive well outside the human body. HIV in blood or sexual fluid for example is not infectious after it has been outside the body for a few minutes.
Notes: this answer was updated in January 2018.
Hello can anyone tell me M 152 tablet is used for treating HIV or any other disease.. please reply
Hi Alen,
Its very common that a person who is positive won’t have seroconversion symptoms, this is one of the reasons why people are diagnosed with low CD4 counts.
Now that your friend is aware of their status, the most important thing is that they adhere to their medication. The medication will help their CD4 count to rise as well as to decrease their viral load. Please see here for more info: http://i-base.info/guides/starting
With regards to how long will it take for your CD4 count to rise, its not possible to say, it will however rise.
Being diagnosed can be a shock, and its common to feel devastated. These are all natural emotions. However, HIV is no longer the illness it used to be. HIV is now a very manageable health condition, like negative people we can live normal lives. We can marry, have kids, we can live and live well.
Being able to talk to someone might help. Most countries have some level support systems. Perhaps your friend may wish to think about this.
One of my friend was diagnosed with HIv positive last week. His CD4 count got 166 . He is literally devastated with the report as he didn’t have any classical symptoms of HIV ahead . For now he is started with Avonza (Its a combination of
Tenofovir disoproxil , fumarate lamivudine ,
Efavirenz ) What can he expect in future? How is my life going to be? How long would it take it for those CD4 cells to improve
Hi B Kayula,
There isn’t a cure for HIV, so I’m not sure that these drugs are that you’ve mentioned.
Hi people I hear this new drug called HOO-IMM DRUG can cure HIV.
And also the SONDASHI HERB in Zambia called SF2000 can cure HIV.
Hi Googleitseriously,
Stem cell transplants can help as treatment for people who have cancer. And they are used to treat seriously ill people who would otherwise die of cancer.
If HIV has been cured or gone into remission after stem cell transplant it’s as a side effect of the cancer treatment.
Please see this Q&A When will we get a cure for HIV. And here’s a link to the HIV cure puzzle.
There is a cure for HIV. It’s called a stem cell transfusion. Also cancer… Ask your doctor about immuno therapy or immunoglobulin transfusions.
yes, starting HIV treament immediately without waiting for CD4 test to be done is the best to avoid breakdown of the cell.
The problem is making the drug available
Hi Justin,
Thanks. Yes, starting HIV treatment (ART) as soon as possible is recommended in most guidelines around the world.
There are very interesting Questions and Answers, especially that they are upto date. However, i think for any client tested HIV either 1 or 2 positive on both screening test and confirmatory one, should start treatment as soon as possible to avoid a sudden drop of CD4 count and the manifestation of opportunistic infections (AIDS).