Antiretroviral Drugs

Subject – Science and Tech

Context – People with past exposure to antiretroviral drugs thrice as likely to resist them: WHO

Concept –

It is a combination of daily medications that stop the virus from reproducing.
The therapy helps in protecting CD4 cells thus keeping the immune system strong enough to fight off the disease.
It, besides reducing the risk of transmission of HIV, also helps in stopping its progression to AIDS (a spectrum of conditions caused by infection due to HIV).
Nevirapine (NVP) or efavirenz (EFV)-based regimens were the most frequent ART regimens initiated in 16 of 20 countries reporting survey findings to WHO (2014-2020).

To know about Human Immunodeficiency Virus (HIV), please refer August 2021 DPN.

HIV Strains and Types

HIV-1 and HIV-2

HIV-1 and HIV-2 are two distinct viruses.
Worldwide, the predominant virus is HIV-1. HIV-1 accounts for around 95% of all infections worldwide.
HIV-2 is estimated to be more than 55% genetically distinct from HIV-1.
The relatively uncommon HIV-2 virus is concentrated in West Africa but has been seen in other countries with links to West Africa. It is less infectious and progresses more slowly than HIV-1, resulting in fewer deaths.
However, without treatment, most people living with HIV-2 will eventually progress to AIDS and die from the disease.
While many commonly used antiretroviral drugs are active against HIV-2, non-nucleoside reverse transcriptase inhibitors (NNRTIs) like nevirapine and efavirenz do not work against it.
The best way to treat HIV-2 has been less clearly defined than HIV-1.

Groups within HIV-1

Of these, M is the ‘major’ group and is responsible for the majority of the global HIV epidemic.
Within group M there are known to be at least nine genetically distinct subtypes of HIV-1. These are subtypes A, B, C, D, F, G, H, J and K.