According to a study published in Science and as first reported by CNN, researchers discovered that some participants who got an experimental HIV vaccine developed antibodies capable of neutralizing the virus in Phase 1 tests. A vaccination regimen consisting of two doses eight weeks apart can induce immune responses against the human immunodeficiency virus.
On World AIDS Day, the findings of a clinical experiment published in Science provided “clinical proof of concept” for research into designing boosting regimens to activate immune responses against HIV infection, which currently has no cure and can proceed to AIDS.
Researchers from Scripps Research, the Fred Hutchinson Cancer Research Center, the National Institutes of Health, and other institutions in the United States and Sweden participated in a study in which 35 of 36 patients received the eOD-GT8 60mer vaccine produced broadly neutralizing antibody precursors.
Antibodies are proteins the immune system produces to combat infections; broad-spectrum antibodies kill multiple HIV genetic variations, but producing them by vaccination has proven problematic.
The scientists said that inducing broadly neutralizing antibodies against disorders with substantial antigenic diversity is a “huge problem” for rational vaccine design. To address this issue, the researchers recommend a “germline-targeting vaccine design.”
The eOD-GT8 60mer vaccine candidate was developed to target particular germline antigenic regions to stimulate the generation of broadly neutralizing antibodies. The International AIDS Vaccine Initiative announced a phase 1 clinical trial using eOD-GT8 60mer in 2018 to assess its safety and any potential immune responses.
The study recruited 48 healthy volunteers aged 18 to 50 from two Washington, DC, institutions: George Washington University and the Fred Hutchinson Cancer Research Center.
Eighteen participants received the vaccine in a 20-microgram dose and then again eight weeks later in the same dose with an adjuvant; eighteen received the vaccine in a 100-microgram dose and then again in the same dose with an adjuvant, and twelve people received two doses of a saline placebo. The AS01B adjuvant was created by the pharmaceutical firm GSK. Muscle injections were used to deliver both the vaccination and the placebo.
Immune cells were examined in this study using blood and lymph node samples obtained from study participants. B cells, the white blood cells responsible for antibody production, were studied closely to discover how immunization impacted them.
Participants in the research reported no significant adverse effects, and no new HIV infections were discovered. Almost all (97%) of the 48 participants in the trial had at least one adverse event, such as injection-site soreness, weariness, or a headache. It took fewer than two days on average to address such concerns.
All vaccination recipients and none of the placebo receivers developed antibodies against the eOD-GT8 60mer vaccine after the initial immunization. According to the study’s authors, the incidence of these side effects rose after a second vaccination.
Dr. Julie McElrath, the paper’s co-author, is the vice president and director of the vaccination and infectious disease division at the Fred Hutchinson Cancer Research Center. According to her, a second Phase 1 investigation of this vaccine candidate is ongoing.
According to Dr. Timothy Schacker, vice dean for research and program director in HIV medicine at the University of Minnesota Medical School, who was not involved in the study, this HIV vaccine candidate is novel because it was designed to stimulate the development of broadly neutralizing antibodies.
When asked why previous HIV vaccinations “didn’t create these widely neutralizing antibodies,” he said, “we’ve made and tested them.” These antibodies are so potent that they may be dubbed “super.” Antibodies that can neutralize a broad range of antigens are more effective. They have significantly more power over everything than anybody else.
According to Paul Schacker, a researcher, new data shows that vaccination can create broadly neutralizing antibodies, which may have implications beyond developing HIV vaccines. It has proven challenging to generate vaccines for some viruses, but “the hope is that if you can build this type of immunity in people, you can protect them from some of these viruses,” he added. As a result, this is a significant advancement.
While this is “exciting science,” according to Dr. Carlos del Rio, co-director of Emory University’s Center for AIDS Research and executive associate dean of Emory School of Medicine at Grady Health System, who was not involved in the new study, “much more work needs to be done” before this vaccine can be considered for public use.
Del Rio proposed deploying widely neutralizing antibodies to halt the spread of HIV. Although positive findings have been discovered, it will take some time before this can be utilized as a vaccine. Without financing for such studies, an HIV vaccine and, if successful, further vaccines cannot be created.
