Why the most virulent HIV mutation ever discovered shouldn’t alarm us
A new variant of the HIV virus, described as “highly virulent”, was revealed this Thursday in an article in the scientific journal Science.
Named “VB variant”, short for “virulent subtype B variant”, has been shown to lead to a higher viral load in the blood compared to other virus types; be more transmissible; and decrease the body’s T-CD4 defense cells more quickly.
The authors of the research, led by a team from the University of Oxford in England, estimate that the variant emerged in the Netherlands in the late 1980s and 1990s, spread in the 2000s and began to lose strength from 2010.
But this is the first time that the variant has been described and mapped in individuals: BV infection was confirmed in 109 people analyzed in the study, the vast majority in the Netherlands (the researchers also detected one case in Switzerland and one in Belgium).
One of the authors, researcher Chris Wymant, explained by email to BBC News Brazil that the results should not concern the population, because the ideal answer for this and other variants of HIV already exists: testing and treatment.
The study contains good news. Compared to other types of HIV, the VB variant proved to be more virulent, transmissible and aggressive in people who had not yet undergone treatment. However, after treatment, people with the VB variant began to show indicators of mortality and CD4 cell recovery similar to those with other types of HIV.
“The discovery of this variant reinforces the importance of guidelines that already exist: that people at risk of contracting HIV have access to regular testing, allowing early diagnosis, followed by prompt treatment”, wrote Wymant, a principal investigator at the University of Oxford and a specialist in the evolution of viruses.
HIV is the virus that causes Acquired Immune Deficiency Syndrome (AIDS).
UNAIDS (Joint United Nations Program on HIV/AIDS) estimates that 37.7 million people were living with HIV worldwide in 2020, year in which 1.5 million new infections occurred.
That year, some 680,000 people died from AIDS-related health problems (compared to 1.9 million in 2004 and 1.3 million in 2010).
In 2020, 73% of people with HIV had access to treatment, which is now drug-based (often just one pill a day) and considered highly effective.
Viral load 3 to 5 times higher
HIV has some subtypes, strongly related to locality.
For example, in Africa, the most common subtypes are A, C, and D; in Europe, subtype B. According to a study published last year, in Brazil, subtype B is also the most frequent.
Wymant explains that within the subtypes, there are branches into variants.
“Finding a new variant is normal, but finding a new variant with unusual properties is not. Especially one with greater virulence”, says the researcher.
“The worst case would be the appearance of a variant that combines high virulence, high transmissibility and resistance to treatment. The variant we discovered has only the first two of these features”.
At the time of diagnosis, before treatment, people with the VB variant had a viral load 3.5 to 5.5 times higher than that seen in other types of HIV; the rate of CD4 cell decline was twice as fast, putting them at much faster risk of developing AIDS.
The researchers say the variant was possibly the result of mutations that occurred over time and was only revealed now for a few reasons, including the fact that genetic sequencing of samples from people with HIV is relatively recent.
The investigation of the variant began because the scientists involved in the project BEEHIVE detected 17 individuals with an unusually high viral load.
BEEHIVE was created in 2014 with the goal of monitoring the influence of genetics on HIV infections, and it does that by tracking the health of patients in European countries and Uganda.
As the researchers genetically analyzed samples from these and more patients, they detected a new variant.
“We consider that the virus (in the form of the VB variant) emerged despite a strong treatment program in the Netherlands, and not because of treatment. The other side of the coin is that the excellent following in the Netherlands has led to a variant like this being detected”, says Wymant.