The variant is not only more contagious, but also more harmful.

The new variant is referred to as the VB variant, researchers write in the magazine science. The variant was discovered in the Netherlands and probably originated somewhere in the late eighties or early nineties of the last century. Research shows that the variant is both more contagious and more dangerous. But the good news is that the immune systems of people infected with the new variant recover just as quickly after treatment as that of people who have other variants of the HIV-1 virus.

The research

The researchers discovered the new variant thanks to the BEEHIVE research project (Bridging the Epidemiology and Evolution of HIV in Europe). Within this project, scientists randomly examine HIV-1 viruses that occur in Uganda and Europe. The aim is to gain more insight into the evolution of the virus. And during this research project, the scientists came across a until recently unknown variant of the HIV-1 virus. This variant was found in the sample in 17 people, 15 of whom came from the Netherlands. Because the variant was mainly found among Dutch patients, the researchers checked whether they could also find the virus variant among a much larger group of Dutch people (6700 HIV-positive patients). The research shows that no fewer than 92 of these Dutch people were infected with the VB variant.

More contagious and more dangerous

And this variant has special properties, according to follow-up research. For example, individuals infected with this variant (prior to antiretroviral treatment) appear to have between 3.5 and 5.5 times more virus particles in their blood than individuals infected with other HIV variants. They are also more likely to transmit the virus to others. In addition, the VB variant also appears to be more harmful to the immune system. For example, the number of CD4 cells (which play an important role in our immune system) decreases 2 times faster in people with the VB variant before treatment than in people with another HIV variant. In concrete terms, it means that people with the ID variant – without treatment – ​​have a greater chance of developing AIDS. Fortunately, the research also shows that the VB variant can be treated just as well as other variants.

“The public need not worry,” said Chris Wymant, lead author of the new study. “The discovery of this variant only emphasizes once again how important the measures already taken (such as regular testing of people with an increased risk of HIV and the early diagnosis and treatment of patients) are. In this way we limit the damage that HIV can do to the immune system and we ensure that the virus is suppressed as quickly as possible and that infecting others is prevented. Those principles also apply equally strongly to the VB variant.”

Long run-up

This VB variant has also been around for a while, according to the research. Based on small genetic variations between the VB variants of the HIV-1 virus found in different individuals, the researchers think that the variant originated around thirty years ago. There are several reasons why it took so long to identify the new variant, Wymant explains. “HIV affects individuals in a variety of ways: some develop AIDS within months, others develop symptoms for decades, and some have viral loads thousands of times higher than others. Until recently, it was thought that all this could be traced back to the immune system: one immune system could fight the virus better than the other. But in 2007, Professor Christophe Fraser (also one of the authors of this new study, ed.) suggested that the virus itself also mattered and that not all viruses are equally likely to cause severe or mild HIV infection. It took years for that idea to be accepted and finally the BEEHIVE project was started in 2014 to find out which changes in the genome of the virus are relevant for the virulence (in other words: the infectiousness, ed.) of the virus.” It then took several years before there were methods for sequencing HIV-1 virus genomes on a large scale. “And it also took several years to complete this specific study, because we describe the VB variant from many different angles. In addition, it has of course also been two very busy years for us epidemiologists.”

special

It is remarkable that the research has now resulted in the discovery of a new HIV-1 variant that is more contagious and more dangerous. “HIV mutates very quickly,” says Wymant. “Every patient has a virus that is different and that virus also changes over time.” And so the HIV-1 virus already has different variants. And yet the discovery of the VB variant is unique. “Finding a new variant is normal,” says Wymant. “But finding a new variant with unusual properties is not that. Certainly not when it comes to a variant that is much more contagious.”

Originate
It is currently unclear how exactly the variant originated. “New forms of existing viruses can arise in different ways. For example through recombination.” This occurs when two different viruses simultaneously infect a cell and then exchange pieces of RNA during the replication process. However, the VB variant does not appear to have originated in this way. “It appears that the virus acquired the mutations one at a time over a longer period of time.” A more appropriate explanation, then, is that the virus acquired the mutations during a long transmission chain, passing from one person to another, gradually acquiring the many mutations that have now been discovered in one fell swoop. “A third possibility is that the virus has caused an unusually long infection in one individual, without this individual undergoing successful treatment aimed at stopping the virus from multiplying and evolving. Unfortunately, we don’t currently have the data needed to determine whether the virus evolved in multiple or one individual. That’s because that evolution largely took place before 1992, at which time most HIV patients had not yet identified the genetic sequence of the virus they were infected with.”

The Netherlands

At first sight it is remarkable that the new variant originated in the Netherlands. The good care that HIV patients in our country can rely on can seriously hinder the evolution of new variants, explains Wymant. “The Netherlands has been providing good care to HIV patients for years by offering antiretrovirals to as many people as possible as quickly as possible. Such successful treatment not only improves the health of the patient undergoing it, but also prevents the patient from transmitting the virus to others. And that also denies the virus the opportunity to evolve into a more contagious variant. Because: viruses cannot mutate if they cannot replicate. We therefore state in our study that the new variant arose despite and therefore not because of the strong Dutch treatment plan.” So it’s just a matter of bad luck. “On the other hand, it is true that the excellent monitoring of the virus in the Netherlands makes it more likely that we will notice such a new variant (if it does arise anyway).

Return

By far the most cases of the VB variant have been found in the Netherlands to date. “In our data, we found one more individual in Switzerland with this variant. And in Belgium, one individual is also known with this variant,” says Wymant, who suspects that more cases are waiting to be discovered elsewhere. “By making the genetic sequence of the variant public, we now enable researchers in different countries to look up their own data.” It should show how widespread the VB variant really is. In the Netherlands, the variant has been on the decline since 2010. “This is probably the result of Dutch efforts to reduce the transmission of all HIV viruses – regardless of which variant it is.”

The discovery of the new variant naturally raises the question of whether more variants are waiting to be discovered. Wymant is clear: “Absolutely, both for HIV and for other pathogens that cause infectious diseases. And that is why it is so important to routinely collect genetic data from pathogens.”