The two-year-long COVID-19 outbreak has demonstrated globally that new mutations in the genetic sequence of the virus can have a significant impact on the transmissibility of the virus and the damage it causes. For years, scientists have feared that this could happen to the human condition of the virus (HIV), which has so far affected 38 million people worldwide and killed 33 million people.
Successful treatment limits the rate at which HIV destroys an individual's immune system and endangers their health
A study published Feb. 3 in Science, a top international academic journal, confirmed this concern, with researchers from the Oxford University's Big Data Institute and the Dutch AIDS Surveillance Foundation discovering a more toxic and destructive strain of HIV, the virulent subtype B. Studies have shown that the VB variant damages the body's immune system twice as fast as other HIV variants, and the viral load is 3.5 to 5.5 times higher than the latter. This means that the VB variant makes it faster for infected people to develop AIDS and a higher risk of spreading the virus to others.
The researchers estimate that the VB variant first appeared in the Netherlands in the late 1980s and 1990s. The results of the study showed that the VB variant had infected 109 people, most of them in the Netherlands. However, experts note that currently available HIV treatments are just as effective for the VB variant, and that "the public need not worry." After receiving antiretroviral therapy, patients infected with this variant were similar in immune system recovery and survival rates to those infected with other HIV variants.
The researchers say the variant carries many mutations, and these mutations are scattered throughout the genome
This variant appeared as early as the last century
"Going downhill" since 2010
The researchers initially discovered the presence of the VB variant in BEEHIVE, a project that brings together a multi-country database of HIV populations, which aims to better understand the biology, evolution and epidemiology of HIV, collecting HIV-positive samples from 7 countries in Europe and across Uganda. The lead authors of the study, who are also key members of the project, identified for the first time that 17 HIV-positive patients were infected with this "unique" variant of HIV, and that these patients carried "surprisingly high" concentrations of the virus in their blood early in the infection.
Since 15 of these patients were from the Netherlands, the researchers then analyzed data from more than 6,700 HIV-positive people in the Netherlands to identify another 92 people infected with the same variant, bringing the total number of infections to 109. According to available clinical data, these 109 people carried a viral load 3.5 to 5.5 times higher than those infected with other B-type virus strains, and the human immune system was damaged twice as fast as other HIV variants. In addition, the variant carries many mutations that are scattered throughout the genome, so they are currently unable to determine a single, isolated genetic cause of the virus's increased toxicity.
"Prior to this study, it was known that the HIV virus's genes were linked to toxicity, which means that the evolution of a new variant may alter its impact on human health." Lead author of the study, Dr Chris Wiymant from the University of Oxford's Institute for Big Data, said: "The discovery of the VB variant proves this and provides a rare example of the risks posed by the evolution of viral toxicity. ”
By analyzing patterns of genetic variation in the samples, the team estimated that the VB variant first appeared in the Netherlands in the late 1980s and 1990s, and that in the 2000s it spread faster than other HIV variants, but its rate of spread has been declining since around 2010. Wiymant noted that during this period, both the VB variant and the absolute number of case infections other than the VB variant declined, "probably because the Netherlands was vigorously reducing any HIV transmission at that time."
Before receiving treatment, the number of CD4 cells in patients infected with the VB variant dropped sharply, and the immune system was destroyed more quickly
Existing HIV therapies are effective for this variant
Experts say the public need not panic
The researchers note that it is unclear how the VB variant appeared, and one possible reason is that an individual has been infected with HIV for an unusually long time, but has not received treatment to stop the virus from replicating and evolving. If an infected person is not treated, the VB variant is likely to cause an infected person to develop AIDS within two to three years of initially being diagnosed with HIV, Wiymant said. For other HIV strains, which on average occur within six to seven years of initial diagnosis, a similar degree of exacerbation occurs, and "the progression of the disease is faster in older adults."
"Thankfully, studies have found that antiretroviral drugs (the standard treatment for HIV) treat the VB variant as well as other versions of the HIV virus." "For a person who receives successful treatment, the immune system stops the hive from getting worse, while stopping the spread of the virus to other individuals," Wiymant said. The researchers emphasized that after receiving existing HIV treatment, the immune system recovery and survival rates of patients with the VB variant were similar to those of other HIV variants. However, since the VB variant causes the immune system to be compromised more quickly, it makes it crucial for infected people to be diagnosed as early as possible and start treatment as soon as possible.
Professor Christopher Fraser of the University of Oxford's Big Data Institute, senior author of the study, added: "Our findings underscore the importance of WHO guidance that people at risk of HIV infection can be regularly tested for early diagnosis and then immediate treatment. This limits the rate at which HIV destroys an individual's immune system and endangers their health, and it also ensures that HIV is suppressed as soon as possible, thus preventing transmission to other individuals. "In addition, further research into the mechanisms that lead to the more transmissibility of the VB variant and the destruction of the immune system could uncover new targets for the next generation of antiretroviral drugs."
Red Star News reporter Hu Yiling
Edited by Pan Li
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