New, more virulent and transmissible variant of HIV discovered

Researchers have identified a highly contagious variant of the Human Immunodeficiency Virus (HIV), which began to circulate in the Netherlands in the 1990s. A rare scientific finding that, however, should not cause panic, they clarify.

The variant responds to existing treatments and has been in decline since 2010. “There is no reason to be alarmed”, assured Chris Wymant, a researcher in epidemiology at the University of Oxford and lead author of the study, published in the journal Science.

However, the discovery may help to better understand how HIV, which causes the disease AIDS, attacks cells.

The research also proves that a virus can evolve to become more virulent, a widely studied scientific hypothesis in theory, but with few examples so far.

In total, the researchers found 109 people infected with this variant, only four of them outside the Netherlands (in Belgium and Switzerland). Most were men who have sex with men and of a similar age to people infected with the virus in general.

The variant developed in the late 1980s and 1990s, and spread more rapidly in the 2000s. Probably thanks to the efforts of the Netherlands in fighting the disease, it has been on the decline since 2021.

She was baptizedV-B variant” for “virulent variant of subtype B”, the most common in Europe.

500 mutations

The HIV virus is constantly changing, and the variant discovered has more than 500 mutations. “Finding a new variant is normal, but finding a new variant with unusual properties is not. Especially with increased virulenceWymant explains.

The first person in the study to be identified with this variant was diagnosed in 1992 (with an incomplete version) and the last in 2014. Once treated, patients are no more at risk of complications than others.

So what does increased virulence mean?

Disease progression is usually measured by the number of CD4 T cells in the blood, which are part of the immune system and are targeted by the virus. People infected with the variant had a lower CD4 count than the rest at diagnosis, with an estimated decline twice as fast.

The researchers calculated that, without treatment, the dangerous threshold of 350 CD4-T cells per microliter of blood would be reached in 9 months for patients with this variant, compared to three years for the other patients.

In addition, the viral load (amount of virus in the blood) of those infected with this variant was also significantly higher, and apart from its virulence, the researchers also showed that it is highly transmissible.

Importance of projections

“Our results highlight the importance of regular access to testing for people at risk of contracting HIV, to enable early diagnosis and start treatment immediately thereafter.”, highlighted the epidemiologist Christophe Fraser, co-author of the study.

Fraser is behind the Beehive project, which collects data from patients in eight countries and was created in 2014 to analyze the extent to which mutations in the virus could have an impact on the disease when it develops.

The researchers were unable to explain which specific mutations of the VB variant caused its high virulence, or through what mechanism.

“This is a warning, we should never be too presumptuous and assume that a virus will evolve to become more benign.Wymant stressed.

It is a conclusion that is of interest in the context of learning more about viruses in the midst of the C0VID-19 pandemic.