Category: HIV

Vaccine Trial Will Determine Moderna Efficacy in People with HIV

Image by Sergey Mikheev on Unsplash

A highly anticipated clinical trial in eight sub-Saharan countries is the first to specifically evaluate the efficacy of a COVID vaccine in people living with HIV, including those with poorly controlled infections. It also is the first study to evaluate the efficacy of vaccines – in this case, Moderna mRNA-1273 – against the Omicron variant of SARS-CoV-2.

In addition to examining the efficacy of COVID mRNA vaccines in people living with HIV, the study investigators seek to identify the optimal regimen for this population and how it might vary based on whether an individual has previously had COVID-19 or not.

The trial will be conducted in East and Southern Africa – regions of the world that have been highly impacted by HIV. It is expected to enrol about 14,000 volunteers at 54 clinical research sites in South Africa, Botswana, Zimbabwe, Eswatini, Malawi, Zambia, Uganda and Kenya, where adult HIV prevalence ranges from 4.5% to 27%.

“Sub-Saharan Africa has been hit hard by the COVID pandemic, but access to effective vaccines, especially mRNA technology, has been very limited,” said Dr. Nigel Garrett, co-chair of the study and head of Vaccine and HIV Pathogenesis Research at the Center for the AIDS Program of Research in South Africa (CAPRISA). “The Ubuntu trial will provide safety data to regulators and assess correlates of protection from COVID-19, and it will answer important questions on mRNA vaccine dosage regimens among people living with HIV.”

About 12 600 people living with HIV and about 1400 who are HIV-negative are expected to be enrolled in the study. About 5000 will have previously had COVID, confirmed by an antibody blood test done at initial enrollment. All participants will receive the Moderna vaccine, but dosages and schedules will vary depending on previous SARS-CoV-2 infection. Participants living with HIV will get access to optimal HIV treatment throughout the trial.

“This region faces a huge HIV burden,” said Dr Glenda Gray, Ubuntu study protocol lead adviser and president of the South African Medical Research Council (SAMRC). “Although safe and effective vaccines have been developed for COVID-, HIV and COVID are on a collision course,” she added. “The impact of COVID-19 on people living with HIV is a concern for the continent, particularly in light of the recently-sequenced omicron variant set to drive South Africa’s fourth wave and further infections globally.”

Dr Philip Kotzé, one of the lead study investigators, said the Ubuntu study would not be possible without the crucial participation of rural communities across Southern and East Africa. “These communities have been disproportionately impacted by the twin pandemics of HIV and COVID-19, and they now have an unprecedented opportunity to help advance science and improve our understanding of the immune response to SARS-CoV-2 in the context of HIV.”

Dr Larry Corey, principal investigator of both the HIV Vaccine Trials Network (HVTN) and the COVID-19 Prevention Network (CoVPN), and co-leader of the network’s vaccine testing pipeline, said this study seeks to address the knowledge gap around HIV status and COVID vaccination.

“Vaccination and treatment are critical for those who face the dual threat of HIV and COVID, as they remain at high risk of acquisition and transmission and potentially can be the origin of future variants,” Dr Corey said. “It is imperative that we as scientists and as society double-down on global efforts to find and make available effective vaccines and treatments. This study represents an important step forward in our efforts to reduce the burden of COVID among HIV-infected persons and understand whether current dosage regimens are adequate.”

Source: HIV Vaccine Trials Network

HIV Prevalence Among Transgender People Remains High

HIV Infecting a T9 Cell. Credit: NIH

A new analysis published in PLOS ONE highlights the worldwide prevalence of HIV among transgender people, demonstrating the need for continued prevention efforts. 

Transgender individuals have an increased risk of HIV infection,  due to factors which are numerous, complex, and dynamic. Recent years have seen updates in HIV prevention measures and so it is important to update knowledge of HIV among transgender individuals in order to inform further prevention efforts.

Applying a statistical method called random-effects modeling, the researchers conducted a meta-analysis of all 98 peer-reviewed publications on HIV prevalence among transgender individuals that appeared between January 2000 and January 2019.

The researchers found that, during the study period, 19.9% (confidence interval [CI] 14.7–25.1%) of trans feminine individuals were HIV positive, as were 2.56% (CI 0.0–5.9%) of trans masculine individuals. Compared with other individuals aged 15 and over, trans feminine people were 66 times more likely (51.4– 84.4) to have HIV, and trans masculine people were 6.8 times more likely (3.6–13.1).

The authors note that their findings counter presumptions that trans masculine individuals are not at risk for HIV. Meanwhile, they found, prevalence varied in different geographic regions, with Africa and Latin America appearing to be more impacted.

Overall, these findings reaffirm that transgender individuals face a disproportionate burden of HIV. The researchers call for increased efforts to meet the unique HIV prevention and care needs of this population.

Continued monitoring will require more data and research, especially to determine how prevalence is influenced by pre-exposure prophylaxis (PrEP)—medications that prevent HIV infection. Such research will be especially important considering that the new study only included data up to 2019, and PrEP treatment has expanded since then.

Source: MedicalXpress

Too Few Children with HIV are Virally Suppressed

Photo by sergey mikheev on Unsplash

Globally, less than two thirds of children and adolescents living with HIV who are receiving treatment are virally suppressed, according to new research published in The Lancet HIV.

Viral suppression [PDF] for HIV means that treatments are protecting health and preventing the transmission of HIV to others. UNAIDS has set a target of achieving 95% viral suppression among all people living with HIV on treatment by 2030.

“We estimate viral suppression one, two and three years after people start taking antiviral treatment, so that we can understand how well the treatments are working over time,” said Professor Matthew Law from the Kirby Institute.

“The data among adults on treatment in our studies show that viral suppression was achieved in an estimated 79% of adults at one year, and 65% at three years. However, viral suppression is poorer among children, at an estimated 64% at one year and 59% at three years.”

Senior study author, Dr Azar Kariminia from the Kirby Institute, said there are unique barriers to achieving viral suppression for children and adolescents. “It can be challenging for them to take treatment regularly, and children rely on caregivers who are often having to manage their own medical needs. There are also a range of factors that stem from stigma and discrimination, including a fear of disclosing the child’s HIV status.”

For this study, the researchers analysed data from 21 594 children/adolescents and 255 662 adults from 148 sites in 31 countries who initiated treatment between 2010 and 2019.

Dr Annette Sohn, from amfAR’s TREAT Asia program, is Co Principal Investigator for IeDEA Asia-Pacific (along with Prof. Law). She says that “while there has been substantial progress in the global response to HIV, the needs of children and adolescents often fall behind those of adults. Our efforts must extend beyond ensuring access to paediatric medicines to address the social and developmental challenges they face in growing up with HIV if we are to achieve the WHO targets by 2030.”

Viral load testing is essential to find out whether HIV treatments are working effectively. It is recommended by WHO at six and 12 months following the initiation of treatment, and then every 12 months thereafter. While viral load testing is common in high-income countries, scaling up accessible viral load testing in resource-limited settings remains a challenge.

With Australian government funding, the Kirby Institute and the Papua New Guinea Institute of Medical Research (PNGIMR) are partnering with the PNG government and a consortium of partners are implementing a program called ‘ACT-UP PNG’ which will scale up HIV viral load testing in two provinces with high HIV rates.

“Our work is ensuring that infants and children are afforded the same access to testing and treatment as other people with HIV,” says Dr Janet Gare from the PNGIMR and a Co-Principal Investigator on ACT-UP-PNG.

Instead of doing viral load testing in distant laboratories, ACT-UP PNG provides same-day molecular point-of-care testing in HIV clinics.

“This brings HIV viral load testing closer to patients, which currently includes children aged 10 and older, and adolescents,” says Dr Gare. “However, we are also pioneering the implementation of a diagnostic platform that will allow the same access to timely HIV viral load testing and results for infants six to eight weeks of age, and children up to nine years, who are currently unable to be included in point-of-care methods.”

Scientia Associate Professor Angela Kelly-Hanku says that these technologies will make testing for viral suppression in infants and children easier.

“We cannot end AIDS without addressing the inequalities that exist between paediatric and adult HIV programs. Projects like ACT-UP make a real difference and bring us closer to achieving the UNAIDS targets.”

Source: University of New South Wales

Differences in Drug Onset Explain Development of Resistance

HIV invading a human cell
HIV invading a human cell: Credit NIH

Researchers examining the development of resistance to HIV drugs have uncovered a mechanism of drug resistance development in combination therapy, where ‘windows’ open up for resistance to develop.

In the late 1980s, when HIV treatments were first introduced, patients would often develop resistance to those treatments within six months. The introduction of triple-drug treatment regimens in the 1990s was intended to rectify that. Even if the virus developed resistance to one drug, two others would still knock it out – in theory. Unfortunately, some patients still develop resistance, leaving scientists with a critical question to answer: Why?

“There’s all these things that we still don’t understand, like why do we even get resistance when treating with three drugs,” said San Francisco State University Associate Professor of Biology Pleuni Pennings. “We understand why it is becoming less common, but it should have been zero all along.”

Prof Pennings and her colleagues offer explanations for this phenomenon in a study published in eLife.

Several interesting observations were noted from analysis of HIV patient records. Drug resistance can evolve years after successful therapy, often the result of sequential mutations that occur in a predictable order. Current models could not explain these observations, and while some studies identify mutations that confer drug resistance, they don’t address how and where they arise.

Drawing on two computational models, the researchers suggest that these observations may result from drug heterogeneity over time and throughout the body. While patients receive three HIV therapies simultaneously, drugs have different half-lives and patients do not always adhere to therapy regimens. This could create opportunities for drug resistance evolution, during a window when only one drug is active. Drugs also don’t uniformly penetrate the entire body, meaning that in some locations in a patient’s body, only one of the drugs might be active, creating another evolution and escape opportunity.

“I think one main reason why we should care is actually not because of HIV but because of drug resistance in other situations,” Prof Pennings explained.

Although drug resistance among patients with HIV is fairly low, drug resistance to multidrug therapies is a big problem for diseases such as malaria and tuberculosis. In addition, the COVID pandemic and the rise of variants show how our understanding of evolving pathogens is still lacking.

“In a way, HIV is the poster child of how we solved drug resistance. … [But] if we don’t understand how we did it, then it’s really hard to take these lessons to other situations,” Prof Pennings said.

Source: San Francisco State University

Scientists Find Second HIV Patient Achieved a ‘Sterilising Cure’

HIV infecting a human T9 cell. Credit: NIH

In a study published in the Annals of Internal Medicinescientists have reported the identification of a second HIV patient who appears to have completely eliminated HIV from their systems in a ‘sterilising cure’. 

During infection, HIV creates a viral reservoir by inserting copies of its genome into a cell’s DNA. This allows the virus to escape from anti-HIV drugs and the body’s immune response. In most people, new viral particles are constantly made from this reservoir. Antiretroviral therapy (ART) can prevent new viruses from being made but cannot eliminate the reservoir, necessitating daily treatment to suppress the virus.

Some, known as ‘elite controllers’, have immune systems that are able to suppress HIV without the need for medication. Though they still have viral reservoirs that can produce more HIV virus, a type of immune cell called a killer T cell keeps the virus suppressed without the need for medication.

Xu Yu, MD, a physician investigator at Massachusetts General Hospital, led a research group that identified one patient with no intact HIV viral sequence in her genome, indicating that her immune system may have eliminated the HIV reservoir: a sterilising cure. When they sequenced billions of cells from this patient, known as the San Francisco Patient, searching for any HIV sequence that could be used to create new virus, they found no sign. This extraordinary finding, the first known incidence of a sterilising cure without a stem cell transplant, was reported in Nature in 2020.  

Now, Dr Yu’s group reports a second untreated HIV-infected patient, known as the Esperanza Patient who also has no intact HIV genomes found in more than 1.19 billion blood cells and 500 million tissue cells sequenced. This may represent a second instance of a sterilising cure.

“These findings, especially with the identification of a second case, indicate there may be an actionable path to a sterilizing cure for people who are not able to do this on their own,” said Dr Yu.

She further explains that these findings may suggest a specific killer T cell response common to both patients driving this response, with the possibility that other people with HIV have also achieved a sterilising cure. If researchers can figure out the immune mechanisms behind this response, they could develop treatments that teach others’ immune systems to mimic these responses in cases of HIV infection.  

Yu adds: “We are now looking toward the possibility of inducing this kind of immunity in persons on ART through vaccination, with the goal of educating their immune systems to be able to control the virus without ART.”

Source: EurekAlert!

HIV-infected Cells Use Sugars to Avoid Immune Destruction

HIV invading a human cell
HIV invading a human cell: Credit NIH

A new study shows how key features on the surface of HIV-infected cells such as certain sugar molecules help the disease evade detection by the immune system, and how they can be disabled. The findings, published in PLOS Pathogens, represent a first step to eradicating this persistent virus in patients.

“We identified a glyco-immune checkpoint interaction as a novel mechanism that allows HIV-infected cells to evade immune surveillance,” said Mohamed Abdel-Mohsen, PhD, assistant professor in the Vaccine & Immunotherapy Center at The Wistar Institute and coauthor on the paper. “And we developed a novel approach that selectively targets these interactions on the surface of these infected cells.”

Existing treatments can reduce HIV to undetectable levels, but eradication remains elusive, with the disease typically returning quickly when treatment stops. And even when controlled, HIV increases risk for other health problems, including neurological disorders, cardiovascular disease, and cancer.

For the new study, researchers looked at a type of sugar molecule called sialic acid on the surface of HIV-infected cells. These sugars bind with receptors called siglecs on the surface of disease-fighting ‘natural killer’ immune cells. When activated, these receptors act as inhibitors, restraining the killer cells and causing them to stop killing. “We thought, ‘is it possible that these HIV-infected cells are using this interaction – covering themselves with these sugars to evade the natural killer immune surveillance?’” said Prof Abdel-Mohsen.

The researchers found that these infected cells can actually exploit this inhibitory connection to evade immune surveillance. They then investigated whether they could manipulate this connection to make the killer cells more effective at killing HIV-infected cells. Disabling the inhibitors from the killer cells was found to cause the immune cells to attack indiscriminately. The researchers turned to the HIV cells, using the enzyme sialidase to remove the sialic acid sugars that were activating the immune inhibitors but this affected all cells, again causing the killer cells to attack indiscriminately. Finally, they developed a sialidase conjugate linked to HIV antibodies, which only targeted sialic acid on HIV cells. With the sialic acid removed from these cells, the killer immune cells attacked and killed the HIV-infected cells, leaving healthy cells alone.

“The killer cells become a super killer for the HIV-infected cells and they now attack them in a selective manner,” said Prof Abdel-Mohsen. “The discovery could be a missing link in the “shock and kill” approach to HIV treatment that has been a focus of research for the past several years,” he added. This two-step process involves first “shocking” the HIV out of latency so it can be detected, and then stimulating the immune system to “kill” the virus once and for all. However, while effective methods have been discovered to reverse latency, scientists haven’t yet found a way to make HIV-infected cells more killable once reactivated. “We may have the shock, but we don’t yet have the kill,” Prof Abdel-Mohsen said. “Our method actually increases the susceptibility of HIV-infected cells to killing, which is one of the top unmet needs in the HIV field.”

First author Samson Adeniji, Ph.D., a postdoctoral fellow at Wistar, noted that the team’s approach could be tested in combination with broadly neutralizing antibody therapies currently being studied in clinical trials. “By combining approaches, we could turn these immune cells from a cop into a kind of Robocop,” he said.

The researchers also noted that, besides  HIV, the approach could be applied in infectious diseases that may evade the immune system, including hepatitis and COVID. In vivo tests with animals are the next step. They’re also investigating other sugar molecules on HIV that may play a similar role as sialic acid. “HIV-infected cells are likely evading immune surveillance through many potential glyco-immune checkpoints,” Abdel-Mohsen said. “We are investigating other mechanisms and how to break them.”

Source: Wistar Institute

Major Mechanism for Chronic Inflammation in HIV Uncovered

HIV invading a human cell
HIV invading a human cell: Credit NIH

In a groundbreaking study of people living with HIV, scientists found that neutrophils play a role in impaired T cell functions and counts, as well as the associated chronic inflammation that is common with the virus.

Neutrophils make up 60–80% of circulating immune cells in the blood. However, these white blood cells are extremely short-lived and cannot be frozen and thawed like other immune cells, making examining them extremely difficult, said study lead Shokrollah Elahi.

“Neutrophils live for hours to a day or two maximum,” Elahi said. “The body produces a lot of neutrophils, and they do their job and then they die and have to be regenerated in the bone marrow. But despite the fact that neutrophils are the most abundant white blood cells in the blood circulation, their role in the context of HIV has not been very well defined.”

In the study, published in the journal PLOS Biology, researchers examined fresh blood samples of 116 people living with HIV and 60 non-infected individuals. They ran comprehensive sequencing on all the genes expressed in the neutrophils from both groups to determine any differences between them.

“We found that not all HIV-infected individuals have similar types of neutrophils,” said Elahi. “As the HIV disease progresses, neutrophils become more activated and more potent, and in turn activate the body’s T cells, which likely causes some of the problems associated with HIV infection such as inflammation and rapid aging.”

Elahi said neutrophils act like an early alarm system: in response to pathogens, they release proteins to signal other immune cells to the danger. This activation can be high or low, or more or less potent, depending on the severity of the danger and the reaction of other immune cells.

One of these proteins is galectin-9, which Elahi previously linked to severe inflammation and cytokine storms in COVID patients. Elahi’s team reported that when neutrophils sense a danger such as an infection, they become stressed and release the galectin-9. As the protein begins to saturate the blood, it can interact with different immune cells. For example, the team found that galectin-9 reacted strongly with T cells and made them more susceptible to HIV infection, causing a cascading effect that leads to a hyper-immune response and inflammation.

Elahi’s prior work showed that patients with HIV and some forms of cancer had elevated levels of galectin-9 in their blood, but now he was able to identify the major source of the protein.

“We found for the very first time that the neutrophil membrane, through a complex mechanism, is covered like a blanket with galectin-9,” he said. “When neutrophils become highly activated, the secretion of galectin-9 can activate T cells through interaction with another molecule called CD44, which then promotes chronic inflammation in HIV patients.”

This ‘alarm’ reaction of shedding proteins such as galectin-9 was linked to oxidative stress, which is believed to play a role in the development of diseases including Parkinson’s, Alzheimer’s, cancer, heart failure and autism.

Based on his findings, Elahi said preventing galectin-9 shedding might be a powerful tool in reducing many of the negative effects of HIV infection. His team has already made some progress in reducing oxidative stress by using an organic antioxidant compound called phloretin and vitamin C.

“We have been looking at phloretin and vitamin C in the lab and our data are very promising,” Elahi said. “We know that both are good at reducing galectin-9 shedding, so we believe they can prevent the hyper-activation of neutrophils. We hope that our results will spark renewed investigation into the role of neutrophils in T cell activation in other acute and chronic conditions.”

Elahi noted the importance of immediate screening tests for HIV or at-risk people, saying: “If the virus is caught early and they can go on antiretroviral therapy, then it stops disease progression and reduces many of the complications associated with advanced HIV.”

Source: University of Alberta Faculty of Medicine & Dentistry

AstraZeneca Vaccine Confers COVID Protection for People with HIV

Image by Ivan Diaz on Unsplash

Interim results from a phase 1B/2A clinical trial conducted by the Wits Vaccines and Infectious Diseases Analytical (VIDA) research unit showed that the AstraZeneca vaccine conferred COVID protection in people living with HIV.

The findings, published in Lancet HIV, show that the AstraZeneca COIVD vaccine is likely to work as well in people living with HIV compared with people who are HIV negative.

These interim findings are vital for informing the clinical management of people with HIV during the COVID pandemic.

In general, clinical trials which evaluate the safety and immunogenicity of COVID vaccines in people living with HIV are limited, and in Africa they are virtually non-existent. This is despite the overwhelming prevalence of HIV infection in Africa, especially South Africa .

“We searched PubMed for peer-reviewed articles published between 1 January 2019 and 29 June 2021, using the terms ‘safety’ and ‘Covid-19’ and ‘vaccine’, but we did not find any reports that evaluated safety and immunogenicity of COVID vaccines in this population,” said Shabir Madhi, Professor of Vaccinology and Director of Wits VIDA, which led the first South African trial for a COVID vaccine in June 2020.

Compared to the general population, people living with HIV have an increased risk of infectious diseases and have a greater mortality risk when hospitalised with severe COVID.

In addition, compared with HIV-negative individuals, people with HIV are at greater risk for infectious diseases, such as influenza, including during antiretroviral therapy (ART).

Risk factors for severe COVID in people with HIV include more advanced stage of HIV/AIDS, the HIV-1 infection not being virally suppressed, and CD4 counts below 500 cells per microlitre.

The study was an interim analysis of a randomised, double-blind, placebo-controlled, phase 1B/2A trial. In 2020, the trial enrolled 104 people living with HIV were enrolled in the trial, HIV-negative people. Eligibility criteria for people with HIV included being on ART for at least three months, with a plasma HIV viral load of less than 1000 copies per microlitre.

The HIV study was a unique addition to the AstraZeneca COVID vaccine clinical trial, and aimed to assess safety and immunogenicity of this vaccine in people with HIV and HIV-negative people in South Africa. The primary endpoint in all participants regardless of HIV status was the safety, tolerability, and reactogenicity profile of the AstraZeneca COVID vaccine.

Reactogenicity refers to a subset of reactions that occur soon after vaccination, and are a physical manifestation of the inflammatory response to vaccination. Such symptoms include pain, redness, swelling or induration for injected vaccines, and systemic symptoms, such as fever, myalgia, headache, or rash. In clinical trials, information on expected signs and symptoms after vaccination is actively sought.

The interim findings show that the AstraZeneca COVID vaccine was well tolerated and showed favourable safety and immunogenicity in people with HIV, including heightened immunogenicity in SARS-CoV-2 baseline-seropositive participants.

Source: University of the Witwatersrand

J&J HIV Vaccine Fails in Local Trials

HIV invading a human cell
HIV invading a human cell: Credit NIH

Johnson & Johnson and its partners announced preliminary results showing their HIV vaccine trial failed to provide sufficient protection against HIV infection in a population of young women in sub-Saharan Africa.

The vaccine had a favourable safety profile with no serious adverse events.
The Phase 2b HIV vaccine clinical trial was known as the Imbokodo study (also known as HVTN 705/HPX2008), which will now be discontinued. Further analysis of the Imbokodo study is ongoing, and the study has provided enough data to progress with key immunological correlates research.

“The high incidence of HIV among young women in sub-Saharan Africa reminds us that, despite great progress made in treatment and prevention, HIV remains a major health challenge for the region,” said Professor Glenda Gray, President and Chief Executive Officer, South African Medical Research Council (SAMRC) and Imbokodo’s Protocol Chair. “This underscores the need to apply the knowledge that will be gained from this trial to continue to advance the pursuit of a global HIV vaccine.”A parallel, ongoing Phase 3 Mosaico study (HVTN 706/HPX3002) with men who have sex with men and transgender individuals in Europe and Americas will continue due to the different HIV strains that are circulating in the trial areas and the different HIV vaccine regimen.
The HIV regimen consisted of an adenovirus vector containing four mosaic immunogens (Ad26.Mos4.HIV) at four vaccination visits over one year. The Imbokodo regimen contains a soluble protein component (Clade C gp140, adjuvanted with aluminum phosphate) which is administered at vaccination visits three and four. The ongoing Phase 3 Mosaico study is testing a different investigational vaccine regimen that involves the administration of a mosaic-based mixture of soluble proteins (Clade C/Mosaic gp140) at vaccination visits three and four.

Imbokodo participants had four vaccination visits over one year, with the primary endpoint based on new HIV infections through month 24. These data found that 63 of 1109 placebo arm participants compared to 51 of 1079 vaccine arm participants. This analysis demonstrated a vaccine efficacy point estimate of 25.2% (95% confidence interval of -10.5% to 49.3%).

HIV is prevalent in Sub-Saharan Africa, where women and girls accounted for 63 percent of all new HIV infections in 2020. The study enrolled roughly 2600 young women across Malawi, Mozambique, South Africa, Zambia and Zimbabwe. Researchers ensured that any HIV-infected participants in Imbokodo were referred to high-quality HIV treatment and care services. 

Source: PR Newswire

Inconsistent PrEP Use for HIV in High-risk Groups

HIV infecting a human cell. Credit: Seth Pincus, Elizabeth Fischer and Austin Athman, National Institute of Allergy and Infectious Diseases/NIH

A large, in-depth look at US patients taking HIV-prevention drug therapy found strong adherence soon after patients get the prescription, but less consistent use thereafter, particularly among groups considered to be high-priority.

The study, published in JAMA Network Open, examined data from 13 906 members of Kaiser Permanente referred for pre-exposure prophylaxis, or PrEP, therapy between 2012 and 2019. The study found certain groups were more likely to stop taking PrEP: young people, Black and Latino individuals, women, and people with substance use disorders.

The findings suggest targeted strategies are needed to support use of this effective prevention in high-risk groups, said lead author Carlo Hojilla, RN, PhD, a research fellow with the Kaiser Permanente Northern California Division of Research.

“The findings have important implications that suggest access to health care is a great way to get people in the door, but we need more effective strategies for making sure people who have an ongoing need for PrEP stay on the medication,” said Dr Hojilla. “These are groups we want to reach, and we need innovative approaches to keep them engaged in PrEP care.”

Some 88% of patients referred for HIV prevention care received a PrEP prescription, and most (98%) of them filled their initial prescriptions. “These findings were encouraging,” Dr Hojilla said. “Kaiser Permanente has managed to do really well increasing uptake of PrEP therapy.”
However, significant inconsistency in use was seen with about half of users discontinuing PrEP at least once; 60% of those filled a prescription again though the study did not explore the reasons for this. Some users may have discontinued PrEP because of a decrease in risk for HIV acquisition, the authors speculated. Medical mistrust, stigma, homophobia, and transphobia as barriers to PrEP uptake and persistence in some communities have been documented in prior studies. Cost was known to be a concern for some, and the study was done before PrEP was provided at no cost, Dr Hojilla said.

The study was also done before the introduction of a new dosing scheme known as 2-1-1, or on-demand, which allows the user to take PrEP only around the time of a potential exposure to HIV, with a similar level of effectiveness as daily dosing. It’s possible that some of the discontinuation reflected in the study was from patients who opted to not take the drug daily because they had only occasional risk exposure, even prior to 2-1-1 dosing being formally recommended, said senior author Jonathan Volk, MD, an infectious disease specialist with The Permanente Medical Group.

No new HIV infections were seen in those remaining on PrEP, the study found. “This shows how incredibly well PrEP works when taken,” Dr Volk said. “But there are important opportunities for us to maximise the population level impact of this vital therapy. To do this, we need to avoid attrition along the care continuum, especially by assisting patients to stay on PrEP throughout periods of risk for HIV acquisition.”

Source: Kaiser Permanente