While in the 80’s and early 90’s, an HIV infection meant a death sentence for many infected people, today HIV-infected individuals can live a normal life thanks to antiretroviral therapy . The combination of three different drugs (which might be all in one pill) blocks the replication of the virus to such a low level, that it becomes undetectable in the blood. The easiest explanation of the term “undetectable” is that the amount of virus (viral load) in the blood cannot be determined by a commonly used test methods like PCR . However, none of these detection techniques are perfect, therefore individual tests have different limits of detection. When looking into the past in the year 1995, when the virus testing began, it had a limit of detection of 10,000 virus particles per 1 ml of blood. Testing of the viral load has improved over time and the limit has dropped to 50 viral particles per 1 ml of blood. Standard tests today have an even lower limit with 20-50 particles per 1 ml .
There is a broad scale of antiretroviral drugs which can be used to treat HIV-infected individuals. Based on their mode of action, they can be split into 5 categories. The first drug class approved were Nucleoside Reverse Transcriptase Inhibitors (NRTIs). They effectively block the reverse transcriptase by acting as an alternative substrate and thereby terminates the viral replication. Older drugs from this class were proven to cause a certain level of mitochondrial toxicity and therefore they are not used anymore. However, the later drugs NRTIs are still used in the treatment backbone. The second class are non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs) which inhibit the same enzyme by blocking its active site. The third class are protease Inhibitors (PIs) which work on the same principle as NNRTIs, but block another enzyme – the viral protease. Integrase Inhibitors are the most recent class. They inhibit a viral enzyme called integrase and this way they prevent incorporation of viral DNA into the host genome. The last class of drugs are Entry Inhibitors. They interfere with the receptors of the host cells and make them unavailable for the virus.
The current treatment strategy employs a 3-drug regiment against at least two molecular targets. That means that HIV-positive people are taking a cocktail of 3 different substances. The drug manufacturers are taking this in consideration and produce already premixed pills .
Benefits of the treatment
What benefits does an undetectable viral load bring to a HIV-infected person? First at all, elimination of the virus from the blood prevents depletion of CD4 T cells which are the primary host cells of HIV. The recovery of CD4 T cell numbers rapidly improves the overall health condition . The second – but not less important – benefit is that individuals with undetectable viral loads cannot transmit the infection to sexual partners and offspring. However, even with an undetectable viral load, the person is still HIV-positive. That is why it is important for people living with HIV to continue to take their medications even when viral particles are undetectable. Standard HIV tests usually detect anti-HIV antibodies. Thus, people living with undetectable viral load will still have antibodies against HIV, which means they will test positive .
Stigma and discrimination
Although AIDS-related illnesses are no longer a primary threat and people with HIV can live a normal life while representing no risk in HIV transmission, they still face discrimination and stigmatization . People with HIV very often become targets of judgment. Some connect the HIV infection to behavior they consider shameful, for example men having sex with men. They believe that the illness is a result of the moral weakness and could have been avoided. Others still wrongly believe that they can contract HIV through casual contact, such as sharing a drinking glass or touching a toilet seat. All these prejudices, lack of knowledge and fear have many negative outcomes. Due to discrimination and stigmatization of HIV-positive individuals, people who do not know their HIV status are scared to get tested, which might have serious long-term consequences on their health.
We all need to take action to reduce the stigma and discrimination by educating ourselves and others, speaking openly and fearlessly about HIV, pointing out the benefits of being undetectable, stand up and say “no” to any type of discrimination that HIV-positive individuals are facing.
Author: M. Korencak
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Editorial note: Editor’s Note: M. Korencak was supported with an ImmunoSensation Travel-and Workshop Grant.