The new variant has been found mainly in the Netherlands and it is more infectious, but it can be detected with existing tests and responds to treatment
3 February 2022
A more transmissible and potentially dangerous variant of HIV has been found in Europe. The discovery means it is more important than ever for people at higher risk to test for the virus regularly and to start treatment immediately, say doctors.
The number of new HIV infections – all known variants combined – has fallen globally over the past decade, thanks to widespread use of medicines that suppress the virus. The new variant, called VB, is just as treatable as ordinary HIV and can be detected using the same diagnostic tests used for other HIV variants.
There are only 109 people known to be carrying VB, all but two of whom live in the Netherlands. But there could be more people infected who don’t know it. Researchers who sequence HIV should check their databases for more cases of the variant, says Chris Wymant at the University of Oxford.
People with HIV – whether the VB kind or not – who take treatments now have near-normal lifespans and if they don’t miss doses, the virus becomes undetectable in their blood and body fluids, so they cannot pass it on even during sex without a condom. People without HIV can also take the same drugs to avoid catching it.
The new variant was discovered through a project called Beehive. This is aimed at understanding the links between HIV genetics and disease severity, and is based on databases of HIV sequences from people in Uganda and eight countries in Europe.
Wymant’s team initially found VB in 16 people in the Netherlands, one in Switzerland and one in Belgium. Further digging revealed the others, who are all in the Netherlands.
Genetic analysis suggests the variant arose in that country in the 1990s. The number of new VB cases rose quickly from about 2000 and then fell from about 2008. Most of those infected didn’t go on to immediate treatment as this wasn’t recommended at the time.
If untreated, HIV gradually infects more and more immune cells, and a particular type, called CD4 cells, falls over time, until people cannot fight off infections at all and they develop AIDS. People with VB progressed faster to a stage called advanced HIV, when CD4 levels are below 350 cells per millilitre of blood, which shows that the variant is more virulent.
By tracking how much the virus causing each new infection mutated over time, the team worked out that, on average, it took just nine months before newly diagnosed people in their 30s reached the advanced HIV stage. For other variants, it took three years.
“The [VB] virus is going from person to person without evolving much, which is indicative that that process is happening faster than usual,” says Wymant. “So they’re more infectious.”
The analysis doesn’t reveal why this variant is more infectious, though.
“The findings provide further support for frequent testing for those at risk and rapid treatment initiation when diagnosed,” says Caroline Sabin at University College London. “We would have been in a very different situation if we had not had those treatments.”
Journal reference: Science, DOI: 10.1126/science.abk1688
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