A trial of a candidate HIV preventive vaccine has begun recruiting participants in the United States and South Africa. The first phase of the trial will evaluate the safety and ability of a new vaccine called VIR-1388 to induce an HIV-specific immune response in humans. The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, has provided scientific and financial support throughout the life of this HIV vaccine concept and funded this research.
Color transmission electron micrograph of HIV-1 virions (yellow/gold) germinating from the plasma membrane of infected H9T cells (purple/green). Image source: NIAID/NIH
Learn about VIR-1388
VIR-1388 is designed to instruct the immune system to produce T cells that can recognize HIV and signal an immune response to prevent the virus from forming a chronic infection. VIR-1388 uses a cytomegalovirus (CMV) vector, meaning a weakened version of CMV can deliver HIV vaccine materials to the immune system without causing illness in study participants. CMV has been present in much of the world's population for centuries. Most people infected with CMV have no symptoms and do not know they have the virus. CMV can be detected throughout the human body throughout life, suggesting that it has the potential to deliver and safely help humans preserve HIV vaccine materials for long periods of time, potentially overcoming the reduced immunity observed with shorter-lived vaccine vectors.
Funding and cooperation
The National Institutes of Health (NIAID) has been funding the discovery and development of CMV vaccine vectors since 2004 and is co-funding the trial with the Bill & Melinda Gates Foundation and San Francisco-based Vir Biotechnology. The trial is sponsored by Vir and conducted through the NIAID-funded HIV Vaccine Trials Network (HVTN) as study HVTN142.
Test details
The HVTN142 trial is being conducted at six sites in the United States and four sites in South Africa and will enroll 95 HIV-negative participants. Participants will be randomly assigned to one of four study groups: three will receive different doses of the vaccine, and one will receive a placebo. To ensure participant safety, this study will only enroll patients who already have asymptomatic CMV. Preliminary study results are expected by the end of 2024, and an optional long-term sub-study will continue to follow volunteers for up to three years after they receive their first vaccination.
For more information about the trial, visit ClinicalTrials.gov, study identifier NCT05854381.
HIV-infected immune cells. Image source: National Institute of Allergy and Infectious Diseases (NIAID)
More information about HIV
HIV/AIDS remains a major global health problem, with major implications for public health and the global economy. According to 2019 data from the World Health Organization (WHO), an estimated 38 million people are infected with HIV globally. In the same year, there were approximately 1.7 million new HIV infections, 95,000 of which were among children under 15 years old. Sadly, the number of HIV-related deaths in 2019 was approximately 690,000.
In terms of access to treatment, at the end of 2019, 81% of HIV-positive people knew their status. Among this informed group, 82% had access to antiretroviral therapy (ART). Impressively, 88% of those receiving antiretroviral therapy successfully suppressed their viral load, demonstrating the effectiveness of the treatment.
The U.S. Centers for Disease Control and Prevention (CDC) reported that there were more than 34,800 new HIV diagnoses in 2019. As of the end of 2018, there were an estimated 1.2 million people aged 13 and older living with HIV in the United States. Shockingly, 14% of these people did not know they were infected with HIV. It is worth noting that gay and bisexual men accounted for 69% of newly diagnosed infections in 2019.
Prevention and mitigation strategies have evolved over the years, with condom use, needle exchange programs and strong HIV awareness campaigns at the forefront of the fight against the spread of HIV. In addition, pre-exposure prophylaxis (PrEP) has also shown significant results, reducing the risk of HIV infection through sexual contact by nearly 99%. To improve global health, leaders have set an ambitious goal for 2030: 95% of HIV-positive people should know their infection status, 95% of those diagnosed should receive antiretroviral therapy, and 95% of those on treatment should have a suppressed viral load.
However, challenges remain. Stigma and discrimination remain huge barriers to effective prevention, treatment and wider support. Furthermore, while significant progress has been made in some areas, gaps remain in access to critical services. For example, in 2019, sub-Saharan Africa accounted for a staggering 67% of the global HIV-positive population, highlighting regional disparities in the epidemic. As the world grapples with these challenges, continued vigilance, funding and innovative approaches remain critical to stemming the HIV epidemic.