The most virulent variant of HIV known to science was discovered in the Netherlands, according to researchers who said it provided valuable insight into how viruses such as the one behind Covid-19 can evolve.
People infected with the VB variant, as it is called, have an average viral load about four times higher than normal for HIV infection and their immune systems decline twice as fast, putting them at risk to develop AIDS more quickly.
Scientists from the University of Oxford’s Big Data Institute, who announced the discovery with Dutch colleagues in the journal Science, said the VB variant was not a threat to public health because the antiretroviral therapy used regularly to treat people living with HIV works effectively against the new variant.
“The worst-case scenario would be the emergence of a variant that combines high virulence, high transmissibility and resistance to treatment,” said Chris Wymant, the study’s lead author. “The variant we discovered has only the first two of these properties.”
But the researchers said the finding was a timely warning in light of the current debate about how Sars-Cov-2, the virus causing Covid-19, was likely to evolve.
“A lot of people are saying that Sars-Cov-2 is going to evolve to be milder because that’s exactly what viruses do and it’s not in the virus’ interest to kill us,” Wymant said. “What we really need is more examples of what viruses do in the real world – and we’re seeing it go both ways, getting more virulent and less virulent. So definitely not take it for granted that Sars-Cov-2 will just get milder.”
The VB variant was first identified in 17 people in late 2018 during an international project called Beehive, which monitors HIV samples from across Europe and Uganda. Since 15 of the people were from the Netherlands, the team then analyzed data from 6,700 HIV-positive people and found another 92 cases of BV infection across the country, bringing the national total to 109.
“There are probably at least a few other people out there who haven’t been detected yet,” Wymant said. “By making the VB genetic sequence openly available, we allow other researchers in other countries to verify their own private data.”
Analysis does not show origin of VB variant, but researchers believe it likely evolved in an individual who suffered an unusually long HIV infection, as genetic analysis revealed no intermediate steps in viral evolution. The same mechanism has been proposed for the origin of Sars-Cov-2 variants, including Omicron.
Although BV spread faster than other variants during the 2000s, it is now in decline along with HIV as a whole in the Netherlands. The researchers said the variant emerged despite widespread HIV treatment, not because of it, because antiretroviral therapy suppresses transmission.
Joel Wertheim, an evolutionary virologist at the University of California, San Diego, who was not involved in the study, said HIV tended to become less virulent in Uganda and more virulent in the United States. The biological reasons for these changes are unknown.
“The HIV and Sars-Cov-2 pandemics show how viruses can and will develop higher virulence when favored by natural selection,” he added.