Experimental HIV vaccines have been found to induce broadly neutralizing antibody precursors among a small group of volunteers in phase 1 trials. The findings suggest that the vaccine given to her twice, eight weeks apart, could induce an immune response to the human immunodeficiency virus.
Clinical Trial Results Announced on World AIDS Day Thursday journal scienceto support the development of booster immunotherapies to induce an immune response against HIV infection, which has no cure and can lead to the acquired immunodeficiency syndrome known as AIDS. establish.
Called the eOD-GT8 60mer, the vaccine has a “good safety profile,” according to researchers at Scripps Research, Fred Hutchinson Cancer Center, with broad spectrum efficacy in 97% of 36 recipients, or all but one. induced neutralizing antibody precursors. National Institutes of Health and other agencies in the United States and Sweden.
Antibodies are proteins made by the immune system to help fight infections broadly neutralizing antibody It is known to neutralize many genetic variants of HIV, but has been difficult to induce by vaccination.
“Learning how to induce broadly neutralizing antibodies against pathogens with high antigenic diversity, such as HIV, influenza, hepatitis C virus, or the betacoronavirus family, is a major challenge for rational vaccine design.” writes the researcher. “The design of vaccines that target germ cells offers one potential strategy for her to meet this challenge.”
The eOD-GT8 60mer vaccine candidate is germ cell targetThat is, they are designed to induce the production of broadly neutralizing antibodies by targeting and stimulating the appropriate antibody-producing cells.
The International AIDS Vaccine Initiative Start of this Phase 1 clinical trial In 2018, we evaluated the safety of the eOD-GT8 60mer and the immune responses it can induce.
The trial included a total of 48 healthy adults between the ages of 18 and 50 enrolled at two institutions: George Washington University in Washington State and Fred Hutchinson Cancer Center in Seattle.
Of the participants, 18 received 20 micrograms of the vaccine, and 8 weeks later received the same dose of vaccine and adjuvant. 18 he was vaccinated with 100 micrograms of vaccine and 8 weeks later with the same dose of vaccine and adjuvant. Twelve were given saline placebo twice at his 8-week interval. The adjuvant is called AS01B, developed by the pharmaceutical company GSK. Vaccine and placebo were administered into the arm muscle.
Researchers collected and analyzed immune cells from the participants’ blood and lymph nodes during the study. They specifically looked at how B cells, a type of white blood cell that makes antibodies in the immune system, respond to vaccines.
The researchers found no serious adverse events reported among study participants, and no participants acquired HIV infection during the study. About 97% of the 48 study participants, OR All but one reported local or systemic adverse events that were generally mild or moderate, including injection site pain, fatigue, and headache. In most cases, these events were resolved within a day or two.
After the first vaccination, all vaccinees were found to produce antibodies induced by the eOD-GT8 60mer vaccine, but no placebo recipients were found. These vaccine-induced responses increased after the second vaccination, the researchers wrote.
Another phase 1 study of this vaccine candidate is underway, said study author Julie McElrath, Ph.D., senior vice president and director of the Vaccines and Infectious Diseases Division at Fred Hutchinson Cancer Center.
What makes this HIV vaccine candidate unique is that it’s designed to directly target the production of broadly neutralizing antibodies, says Associate Dean and Program Director for Research in HIV Medicine at the University of Minnesota School of Medicine. Dr. Timothy Schucker said. he is engaged in research.
“With HIV, when we’ve designed and tested vaccines in the past, they for some reason didn’t elicit these broadly neutralizing antibodies,” he said. “Call them super-antibodies if you like. Broad-neutralizing antibodies work more efficiently. They’re good at keeping things under control.”
By showing that broadly neutralizing antibodies can be induced by vaccines, the new study could help develop other types of vaccinations, not just HIV vaccines, Schacker said.
“If we can induce this kind of immunity in people, it’s hoped that we can protect people from some of these viruses that we’ve had such a hard time designing effective vaccines for,” he said. This is an important step forward.”
This is “exciting science,” but more work needs to be done before this vaccine can be considered for general use, said Dean, co-director and executive associate of Emory University’s Center for AIDS Research. Dr. Carlos del Rio said: His Emory School of Medicine at Grady Health System was not involved in the new study.
“We know that broadly neutralizing antibodies are a potentially effective strategy for preventing HIV,” said del Rio. “We are far from using this as a vaccine, but this is very exciting science. If so, it can be used for other vaccines.”
HIV vaccines probably need to induce these broadly neutralizing antibodies, or bnAbs, that can recognize globally diverse HIV strains and prevent HIV infection. However, induction of bnAbs by vaccination has so far proven impossible. A key challenge is that bnAbs rarely occur during infection,” said his Penny Moore of the University of the Witwatersrand and the National Institute of Infectious Diseases in South Africa. wrote in an editorial Published with new research.
A “key question” that still needs to be answered is how long the antibodies induced from the initial immunization can persist.
And if the booster shot is too different from the previous vaccine, “antibodies induced by the first vaccination may not recognize the booster and may not mature further,” Moore wrote. “As such, it is not attractive to incorporate many different shots into HIV vaccine therapy. Striking the right balance between the need for antibody maturation to bnAb and its real-world feasibility is essential.”
Last year, more than 38 million people were living with HIV or AIDS worldwide. More than 20 HIV vaccine clinical trials are underway worldwide. According to the International AIDS Vaccine Initiative.
Many people in the United States rely on daily HIV prophylaxis and frequent injections. known as PrEPreduce the risk of infection.
“It’s either a daily pill or a painful injection. It’s an uncomfortable injection at best that you have to get a few times a year,” Schucker says of PrEP.
But protection against the virus would be more accessible once an HIV vaccine was available, he said. We can provide more and better coverage to reduce the chance of infection.”