Virus hunters are always on the lookout, not just for new variants of SarsCoV2. This is demonstrated by the discovery of a new, more aggressive and transmissible variant of the HIV virus, responsible for AIDS. First described in Science, it was named VB (virulent subtype B) by researchers at the University of Oxford who identified it in around 100 people in the Netherlands, where it may have appeared 30 years ago. Fortunately, it is therapy sensitive and does not represent a public health emergency, but it demonstrates once again that viruses don’t always evolve into better ones.
The VB variant was initially identified in 17 HIV positive who had shown unusually rapid progression to the disease. Since 15 of them came from the Netherlands, the researchers led by Chris Wymant decided to extend the survey on 6,700 HIV-positive people of the same nationality, thus identifying another 92 people affected by the new variant.
“It is not uncommon to find new variants of the HIV virus: like all RNA viruses, it mutates easily, and we see it from its great ability to adapt to antiretroviral drugs, becoming resistant”, comments Stefano Vella, professor of Global Health at the Catholic University of Rome. and new president of the new National AIDS Commission of the Ministry of Health. “The Oxford researchers have done an extraordinary job in molecular biology by sequencing the viral genomes isolated from HIV-positive patients who had been shown to get sick with AIDS faster than others. Until now – explains the expert – it was assumed that progression faster depended on the individual variability of the individual patient, and instead this study shows that it may be due to a new, more aggressive viral variant “.
Data shows that VB determines a viral load from 3.5 to 5.5 times higher than that of the HIV-1 virus (the most widespread) and is twice as fast in weakening the immune system, paving the way for AIDS . Infected people react to therapy and have the same survival as other patients, but the aggressiveness of the variant makes early intervention even more important.
From the analysis of the viral genome it is deduced that the VB variant appeared in the Netherlands between the end of the 1980s and the 1990s. After an acceleration in the early 2000s, its spread would then slow down over the last decade. The researchers say the variant appeared ‘despite’ widespread therapies in the Netherlands, and not ‘because’ of the therapies, since effective treatment can block transmission of the virus.
The VB variant “does not represent a public health emergency – reassures Vella – but it gives us an important lesson: it dispels the myth that viruses become better over time. In reality, their evolution occurs randomly and it cannot be excluded that a virus can become even worse “. SarsCoV2 also gave us a clear demonstration. “After the Alpha variant, the Delta appeared, even more virulent and transmissible. Omicron in turn became even more transmissible, although less virulent. This – concludes the expert – shows us that the evolution of viruses is unpredictable and it should not be taken for granted “.