On-Demand Preexposure Prophylaxis in Men at High Risk for HIV-1 Infection

Factors driving decisions in the use of HIV pre-exposure prophylaxis: a real-world study in the United States

Background: Uptake of pre-exposure prophylaxis (PrEP) in the United States (US) remains below target, despite reported high efficacy in prevention of HIV infection and being considered as a strategy for ending new HIV transmissions. Here, we sought to investigate drivers for PrEP use and barriers to increased uptake using real-world data. Methods: Data were drawn from the Adelphi PrEP Disease Specific Programme™, a cross-sectional survey of PrEP users and PrEP non-users at risk for HIV and their physicians in the US between August 2021 and March 2022. Physicians reported demographic data, clinical characteristics, and motivations for prescribing PrEP. PrEP users and non-users reported reasons for or against PrEP use, respectively. Bivariate analyses were performed to compare characteris tics of users and non-users. Results: In total, 61 physicians reported data on 480 PrEP users and 121 non-users. Mean ± standard deviation of age of users and non-users was 35.3 ± 10.8 and 32.5 ± 10.8 years, respectively. Majority were male and men who have sex with men. Overall, 90.0% of users were taking PrEP daily and reported fear of contracting HIV (79.0%) and having at-risk behaviors as the main drivers of PrEP usage. About half of non-users (49.0%) were reported by physicians as choosing not to start PrEP due to not wanting long-term medication. PrEP stigma was a concern for both users (50.0%) and non-users (65.0%). More than half felt that remembering to take PrEP (57.0%) and the required level of monitoring (63.0%) were burdensome. Conclusions: Almost half of people at risk for HIV were not taking PrEP due to not wanting long-term daily medication and about half of current PrEP users were not completely adherent. The most common reason for suboptimal adherence was forgetting to take medication. This study highlighted drivers for PrEP uptake from physician, PrEP user, and non-user perspectives as well as the attributes needed in PrEP products to aid increased PrEP uptake.

Associations of HIV pre-exposure prophylaxis (PrEP) indication, HIV risk perception and unwillingness to use PrEP among people who inject drugs in Baltimore, MD

Background

Perceived HIV risk may impact willingness to initiate PrEP among people who inject drugs (PWID).

Methods

We analyzed baseline data from PrEP eligible PWID in Baltimore, MD. Risk perception was assessed by PWID relative to the average risk of their age group categorized as: higher-than, lower-than, or about average. Participants were informed of PrEP for HIV prevention and asked about their willingness to use daily PrEP. Associations of PrEP indication (categorized as injection risk only vs any sexual risk), perceived HIV risk and non-willingness to use PrEP was assessed using generalized linear models.

Results

Among 489 participants, 61 % were male, 66 % were Black and mean age was 46 years. One-third (35 %) of the participants were aware of PrEP and <1 % had used PrEP in the prior 30 days. Overall, 30 % of PWID reported lower-than-average perceived HIV risk and 18 % reported non-willingness to use PrEP. Participants with injection risk only were more likely (aOR: 2.75; 95 %CI: 1.60 - 4.73) to report having lower-than-average perceived HIV risk compared to those with any sexual risk. Participants with lower-than-average perceived risk were more likely to report non-willingness to use PrEP compared to those with higher perceived risk (adjusted PR: 1.91; 95 %CI: 1.18 - 3.10).

Conclusion

A considerable proportion of PWID eligible for PrEP reported having low risk of HIV acquisition despite being eligible for PrEP. Consistent and tailored PrEP messaging that addresses drug use HIV risk perception may be critical to increasing PrEP uptake among PWID.

Preferences for Starting Daily, On-Demand, and Long-Acting Injectable HIV Preexposure Prophylaxis Among Men Who Have Sex With Men in the United States (2021-2022): Nationwide Online Cross-Sectional Study

BACKGROUND

Long-acting (LA) injectable preexposure prophylaxis (PrEP) and on-demand PrEP may improve overall PrEP uptake among men who have sex with men (MSM), but little is understood about the PrEP option preferences of MSM in practical scenarios where they may choose between various PrEP options.

OBJECTIVE

This study aims to examine the preferences for starting various PrEP options among a US nationwide online convenience sample of MSM from September 2021 to February 2022.

METHODS

Participants reporting no prior HIV diagnosis were provided brief descriptions of each PrEP option and were asked, "If [PrEP option] were available from your local doctor and you could access it for free, would you go to your doctor in the next month to start [PrEP option]?" Those who said "yes" to multiple options were asked to rank them in order of preference. MSM currently taking daily oral (DO) PrEP were asked whether they would switch to on-demand or LA PrEP options. Log binomial models were created to examine the association between willingness to start or switch to on-demand and LA PrEP with various sociodemographic and behavioral factors.

RESULTS

In the analytic sample (N=7760), among the participants who did not use any PrEP in the past 12 months (n=5108, 66%), 54% (n=2445) reported willingness to start at least 1 PrEP option and 41% (n=1845) of participants showed interest in starting multiple PrEP options. Overall, the highest willingness was reported for on-demand PrEP (n=2235, 44%), followed by DO PrEP (n=2174, 43%) and LA PrEP (n=1482, 29%). LA PrEP was ranked first among those interested in multiple options. Characteristics associated with ranking LA PrEP as a first option to start PrEP versus DO or on-demand PrEP were region of residence (residing in the West vs Northeast), report of sexually transmitted infection diagnosis in the past year, report of illicit drug use other than marijuana in the past year, and prior awareness of LA PrEP. Among current DO PrEP users (n=2379, 31%), 58% (n=1386) were willing to switch to on-demand or LA PrEP, and LA PrEP was ranked first among participants who were open to switching to both options. Willingness to switch to LA PrEP was higher among those who used illicit drugs other than marijuana in the past year, who heard of LA PrEP prior to the survey, and those who took 15 or less doses of oral PrEP in the last 30 days.

CONCLUSIONS

LA PrEP was the highest-ranked option among most MSM who were willing to try multiple options or switch from DO PrEP. These findings highlight that LA PrEP might fill coverage gaps among MSM who use illicit drugs, have had a recent sexually transmitted infection diagnosis, and have less than optimal DO PrEP adherence.

Preexposure Prophylaxis (PrEP) for HIV

This JAMA Insights discusses the expanding PrEP options for preventing HIV, including the considerations for initiation and follow-up and implementation challenges of these medications.

Protocol for a randomized controlled trial with a stepped care approach, utilizing PrEP navigation with and without contingency management, for transgender women and sexual minority men with a substance use disorder: Assistance Services Knowledge-PrEP (A.S.K.-PrEP)

BACKGROUND

In the United States, most (~ 70%) annual newly diagnosed HIV infections are among substance-using sexual minority men (SMM) and gender minority transgender women (trans women). Trans women and SMM are more likely to report or be diagnosed with a substance use disorder (SUD) than their cisgender or heterosexual counterparts and the presence of an SUD substantially increases the risk of HIV infection in both groups. Although Pre-Exposure Prophylaxis (PrEP) is highly effective, initiation, adherence, and persistence are exclusively behavioral outcomes; thus, the biomedical benefits of PrEP are abrogated by substance use. SUD is also associated with reduced quality-of-life, and increased overdose deaths, utilization of high-cost healthcare services, engagement in a street economy, and cycles of incarceration.

OBJECTIVE

To determine the optimal (considering efficacy and cost-effectiveness) strategy for advancement along the PrEP Care Continuum among trans women and SMM with an SUD.

METHODS

This study will implement a randomized controlled trial, evaluating two Stepped Care approaches involving A.S.K.-PrEP vs. standard of care (SOC) to determine optimal intervention strategies for trans women and SMM with an SUD (N = 250; n = 83 trans women; n = 167 SMM) for advancement along the PrEP Care Continuum. Participants will be randomized (3:1) to Stepped Care (n = 187) or SOC (n = 63). Participants in the Stepped Care arm will be assessed at 3-months for intervention response; responders will be maintained in A.S.K.-PrEP, while non-responders will receive added attention to their SUD via Contingency Management (CM). Non-responders will be re-randomized (1:1) to either (a) receive A.S.K.-PrEP + CM, or (b) shift the primary focus to their SUD (CM alone).

RESULTS

Recruitment and enrollment began in May 2023. Recruitment will span approximately 36 months. Data collection, including all follow-up assessments, is expected to be completed in April 2027.

DISCUSSION

Trans women and SMM with an SUD have the two highest HIV prevalence rates in the United States, which underscores the urgent need for effective measures to develop scalable behavioral interventions that can encourage advancement along the PrEP Care Continuum. To improve public health, researchers must identify scalable and cost-effective behavioral interventions to promote PrEP initiation, adherence, and persistence among trans women and SMM who use substances.

TRIAL REGISTRATION

This trial has been registered at ClinicalTrials.gov under the number NCT05934877.

Lenacapavir to prevent HIV infection: current prices versus estimated costs of production

BACKGROUND

Despite improvements in treatment and oral pre-exposure prophylaxis (PrEP) access, 1.3 million people acquired HIV in 2022. Six-monthly lenacapavir PrEP could benefit tens of millions of people at high risk of infection. However, prices are currently up to $44 819 per person per year (pppy).

OBJECTIVES

We projected minimum lenacapavir pricing based on generic mass production and a Cost-Plus (Cost+) model.

METHODS

Current active pharmaceutical ingredient (API) and key starting materials (KSMs) costs were obtained from export databases. The routes of synthesis (ROS) were analysed to project a cost of goods (COGs). Formulation, vials and profit margin costs were included using standardized algorithms and Cost+ pricing. We estimated prices with scale-up to supply 1 million then 10 million treatment-years, comparing this with national list prices.

RESULTS

The lenacapavir API is currently exported from India for $64 480/kg on 1 kg scale. Based on the ROS and KSMs, API COGs of $25 000/kg and $10 000/kg are achievable for a committed demand of 1 million (2 million tonnes/annum of API) and 10 million treatment-years, respectively. Including formulation steps, injectable lenacapavir could be mass produced for approximately $94 pppy for 1 million and $41 for 10 million treatment-years, if voluntary licences are in place and competition between generic suppliers substantially improves. Greater scale-up with improvements in manufacturers' ROS could reduce prices further. Currently lenacapavir costs $25 395-44 819 pppy.

CONCLUSIONS

Lenacapavir could be mass produced for <$100 pppy at launch. Voluntary licensing and multiple suppliers are required to achieve these low prices. This mechanism is already in place for other antiretrovirals. To date, Gilead has not agreed lenacapavir voluntary licences with the Medicines Patent Pool.

Increasing event-driven HIV pre-exposure prophylaxis use among gay, bisexual and other men who have sex with men in Australia: results from behavioural surveillance 2019-2023

INTRODUCTION

HIV pre-exposure prophylaxis (PrEP) has been publicly available since 2018 in Australia as a daily regimen. In 2019, clinical guidelines were updated to support guidance on event-driven PrEP (ED-PrEP) use. We assessed trends in the PrEP dosing regimen by comparing daily PrEP use to ED-PrEP among cisgender gay, bisexual and other men who have sex with men (GBMSM).

METHODS

Data from repeated, cross-sectional, national behavioural surveillance surveys were analysed from 2019 to 2023 among participants not living with HIV. Logistic regression models were conducted to assess trends and compared ED-PrEP users to non-PrEP users and daily PrEP.

RESULTS

Among 38,880 participants, overall PrEP use with any regimen increased from 27.6% in 2019 to 42.7% in 2023 (OR = 1.16, 95% CI = 1.15-1.18, p < 0.001). Among 12,922 participants who reported PrEP use in the last 6 months, the proportion reporting ED-PrEP use increased from 7.6% in 2019 to 27.8% in 2023 (OR = 1.41, 95% CI = 1.37-1.46, p < 0.001) with those who reported daily PrEP decreasing from 92.4% to 63.3% (OR = 0.64, 95% CI = 0.62-0.66, p < 0.001). In a cross-sectional sub-sample in 2022-2023 (n = 8840), compared to ED-PrEP users, non-PrEP users were less likely to have received three or more HIV tests in the last 12 months (aRRR = 0.26, 95% CI = 0.22-0.31, p < 0.001), have 2-10 male sexual partners in the last 6 months (aRRR = 0.24, 95% CI = 0.14-0.41, p < 0.001) or 11 or more (aRRR = 0.26, 95% CI = 0.15-0.45, p < 0.001) compared to none, or to report condomless anal intercourse with casual partners (aRRR = 0.38, 95% CI = 0.32-0.46, p < 0.001). Compared to ED-PrEP users, daily PrEP users were more likely to have received three of more HIV tests in the last year (aRRR = 3.73, 95% CI = 3.15-4.40, p < 0.001) and less likely to be born overseas and lived in Australia for less than 5 years compared to being born in Australia (aRRR = 0.64, 95% CI = 0.49-0.83, p = 0.001).

CONCLUSIONS

While daily PrEP remains the most common PrEP dosing regimen among GBMSM in Australia, there has been a steep increase in the proportion of PrEP users who are taking ED-PrEP. Monitoring of PrEP use should continue to adapt to new dosing methods and future PrEP options. As ED-PrEP use increases, further work is needed to ensure those taking ED-PrEP are taking it effectively to prevent HIV.

Understanding Typology of Preexposure Prophylaxis (PrEP) Persistence Trajectories Among Male PrEP Users in the United States

Introduction

Understanding longitudinal patterns of preexposure prophylaxis (PrEP) use among men who have sex with men could offer insights for developing efficient and timely interventions to promote PrEP persistence.

Setting

We extracted 2 years of pharmacy fill records for 4000 males who initiated PrEP in 2017 at a national chain pharmacy in the United States.

Methods

Group-based trajectory models were used to develop PrEP trajectory clusters, with periods of use defined based on optimal PrEP seroprotection probabilities (ie, PrEP use frequency ≥4 doses/week). Multinomial logistic regressions were used to evaluate the associations between sociodemographic covariates and identified trajectory group membership.

Results

We identified 4 distinct groups of PrEP persistence trajectories: (1) persistent use of PrEP throughout the period (persistent user), (2) brief use followed by sustained cessation of PrEP use (brief user), (3) PrEP use up to the mid-term followed by sustained cessation of PrEP use (mid-term user), and (4) PrEP use, followed by cessation and subsequent reinitiation (PrEP reinitiator). Persistent users and brief users accounted for 40.1% and 22.9% of the population, respectively, whereas mid-term users and reinitiators accounted for 18.9% and 18.2%, respectively. Older age at PrEP initiation, commercial insurance as the primary payer of PrEP, and use of specialty pharmacy were found to be associated with persistent PrEP use over the other patterns of nonpersistence.

Conclusions

Subgroups of PrEP users could benefit from PrEP persistence interventions that target specific timings of likely PrEP cessation or considerations of reinitiation.

Acceptability of an automated directly observed therapy (DOT) application for PrEP adherence support among young men who have sex with men: a qualitative exploration

Pre-exposure prophylaxis (PrEP) adherence remains a challenge among young men who have sex with men (MSM). We developed and tested a smartphone application ("app"), "DOT Diary", which combines automated directly observed therapy (DOT) with information about PrEP protection levels, pill-taking reminders, a sexual behavior diary, and a PrEP dosing calendar. To contextualize trial results, we qualitatively explored participants' app experiences. The trial enrolled 100 young MSM in San Francisco and Atlanta. Participants were randomized 2:1 to DOT Diary versus standard-of-care and followed for 24 weeks. Interviews were conducted with 24 intervention participants. Data were analyzed using a memo-writing approach. Most expressed overall satisfaction with the app ("it was good for its purpose"), despite concerns about technical glitches. The most popular app features were the monthly calendar showing days PrEP was taken and information about level of protection based on pills taken. The DOT component helped participants establish PrEP routines. The reminders were "annoying but effective" at motivating dosing. Opinions about the sexual behavior diary varied. Overall, DOT Diary was acceptable; participants were willing to use it daily to record pill-taking. Critical components included the information about PrEP protection levels and calendar, while others may be modified to improve future success.Trial registration: ClinicalTrials.gov identifier: NCT03771638.

Updated guidelines on HIV post-exposure prophylaxis: continued efforts towards increased accessibility

INTRODUCTION

HIV transmission is ongoing in both high- and low-resource settings. Post-exposure prophylaxis (PEP) remains an important tool in preventing HIV; however, PEP is significantly underutilized. The multitude of barriers to PEP implementation include low patient and provider awareness and acceptability, limited access to treatment and prevention services, and high rates of stigma. The World Health Organization (WHO) recently released updated guidance on the delivery of HIV PEP. This commentary aims to highlight the salient changes, evaluate how such recommendations can overcome the existing barriers to PEP implementation and discuss strategies needed to put the updated guidance into practice.

DISCUSSION

The 2024 WHO PEP guidelines continue a trend towards increasing access to PEP. Most notably, the WHO now provides strong recommendations that: (1) PEP be delivered in community settings (e.g. pharmacies, police stations and online platforms), and (2) PEP delivery and monitoring be done via task sharing involving non-specialist health workers (e.g. pharmacists or community health workers). The guidelines also emphasize that the PEP encounter is an important educable moment whereby a transition to pre-exposure prophylaxis among individuals at continued risk for HIV infection should be discussed. The decentralization of PEP delivery has the potential to overcome numerous barriers to PEP implementation, reduce time to initiation and support adherence with the 28-day course. To translate the recommendations into delivery programmes, however, much more work is needed. Detailed templates can help overcome the heterogeneity of both the community settings in which PEP can now be provided and the populations (e.g. survivors of sexual assault, healthcare workers, sex workers, etc.) among whom PEP may be indicated. Training of the workforce will be essential, which should include, as emphasized by the WHO, training in trauma-based care. Novel formulations of and delivery mechanisms for PEP are also emerging, and how such iterations can synergize with decentralized PEP delivery programmes remains to be seen.

CONCLUSIONS

The updated WHO PEP guidelines make major strides towards increasing access to PEP. Realization of such aims will require ongoing evaluation and support given the heterogeneity in who benefits most from PEP.

The Association between Social Support and Pre-Exposure Prophylaxis use among Sexual Minority Men in the United States: A Scoping Literature Review

Sexual minority men (SMM) are disproportionately affected by HIV. Although pre-exposure prophylaxis (PrEP) is an effective way of reducing HIV incidence, PrEP use has remained relatively low. Social support may be one effective factor in increasing PrEP use among SMM, but the association between social support and PrEP use/adherence is not well understood. The objective of this paper was to summarize the current literature on the association of social support and PrEP use among SMM in the United States. A systematic search was conducted using six different databases MEDLINE / PubMed, PsycINFO, Cochrane CENTRAL, Google Scholar, Embase, and Web of Science using terms established from keywords and medical subject headings (MeSH) terms before being adapted to each database. Data were extracted for key study factors (e.g., study population, geographic location, study design) and main findings. This search produced eleven articles: ten manuscripts and one conference abstract. Of these, two were randomized control trials, two were interventions, three were qualitative, and four were cross-sectional. The studies were widespread across the country, but most were in major metropolitan areas. From the articles included in this review, findings were inconsistent in the association between social support; some studies showed null findings, others that only certain sources of social support were significant, and others that there was a significant association between social support and PrEP use. This review highlights the complexity of the relationship between social support and PrEP use among SMM, indicating the need for further research to identify specific types and sources of support that effectively enhance PrEP uptake and adherence. Targeted interventions based on these insights could significantly reduce HIV incidence in the population.

Interest in event-driven PrEP among men who have sex with men using daily PrEP in Mexico in 2019-2020: a cross-sectional assessment in a large-scale demonstration project

This study aimed to evaluate the interest in event-driven PrEP (ED-PrEP) among men who have sex with men (MSM) using daily PrEP in Mexico's PrEP demonstration project between 2019 and 2020. We compared participants interested or not in ED-PrEP during their first-month visit and identified associated factors. Of 1,021 MSM attending their first-month visit, 7% had previous knowledge of ED-PrEP, but 40% were interested in ED-PrEP. However, over 50% perceived the scheme as less protective than daily PrEP. Having doubts about ED-PrEP's level of protection was related to less interest in the scheme (aOR = 0.11; CI = 0.07-0.18), just like reporting perceived barriers such as having frequent sex (aOR = 0.06; CI = 0.03-0.14), unplanned sex (aOR = 0.17; CI = 0.11-0.27), forgetting the medicine (aOR = 0.06; CI = 0.03-0.12), or difficulty carrying the medicine (aOR =   0.13; CI = 0.07-0.25). Finally, reporting not taking PrEP for >20 days in the last month (aOR = 0.05; CI = 0.01-0.27) diminished interest in ED-PrEP. In conclusion, few MSM daily PrEP users knew about ED-PrEP yet many were interested in it, suggesting the importance of awareness campaigns regarding ED-PrEP's effectiveness. The lack of interest in ED-PrEP among participants with poor adherence to daily PrEP indicates that they might prefer long-acting PrEP or HIV prevention strategies without medication.

Pre-Exposure Prophylaxis for HIV: Bioethical, Clinical, and Epidemiological Considerations

Public health authorities are broadly promoting a strategy known as pre-exposure prophylaxis (PrEP) for the prevention of human immunodeficiency virus (HIV) transmission in the context of high-risk sexual activity and injection drug use. However, there are several limitations to this strategy that are underrecognized. This article reviews the primary literature supporting the use of PrEP and explores the unintended consequences associated with its use. Current public health messaging indicates that PrEP reduces the risk of HIV transmission during sex by 99 percent; however, this figure is based on modeling rather than study findings, and real-world efficacy may be significantly lower. PrEP has been associated with increased rates of sexually transmitted infections, risk compensation, HIV drug resistance, low adherence, and drug side effects. To make fully informed decisions, medical professionals and patients should be aware of these pitfalls. Additionally, this article explores the bioethical implications of prescribing PrEP from a Catholic perspective. Although not always morally illicit, PrEP is most often prescribed in the context of sexual activity outside of marriage between a biological male and female, placing the prescriber in cooperation with activity deemed to be immoral by the Catholic Church. While all medical professionals seeking the common good should aim to reduce the transmission of HIV, not all means are morally licit. Conscience protection for medical professionals opposed to this strategy has become increasingly relevant. Thoughtful discernment is necessary when considering PrEP. Summary: The use of CDC material (figure 1) in this article does not imply endorsement by CDC. The material is in the public domain and available on the CDC website free of charge.

Advances in HIV management and challenges in Japan: Current situation of pre-exposure prophylaxis in Tokyo

Since the world's first case series of human immunodeficiency virus (HIV) infection were reported, more than 40 decades have passed. The advancement of HIV treatment and prevention has progressed drastically. Especially, the efficacy of pre-exposure prophylaxis (PrEP) for HIV prevention has been proven by a number of trials and the number of new HIV cases has declined over the years due to the large-scale and rapid implementation of PrEP and universal HIV treatment in multiple countries. However, in Japan, PrEP is not approved or officially supported as of June 2024. Despite of the absence of top-down movement, men who have sex with men (MSM)-friendly private clinics initiated prescriptions of generic medicines for oral PrEP with necessary tests in Tokyo, which greatly contributed to improve access to PrEP. It is of note that current situation of bottom-up PrEP implementation using generic medicines in Tokyo is obviously cost-saving, which is needless to evaluate. However, expense of PrEP is fully out-of-pocket, which will hinder those with low or no income from accessing PrEP services despite the low prices of generic medicines. Furthermore, current PrEP implementation based on user-friendly clinics is functioning only in Tokyo. The role of public health authorities is important to solve these financial and geographical disparities in accessing PrEP services, without impairing existing virtues of accessibility and cost-saving in the current system.

No Man Is an Island: Resiliency Among Older African American Men Living with HIV

African American men face chronic illness earlier in life and earlier death due to higher severity of illness and poor control of chronic diseases than their white male counterparts. Preexposure and post-exposure prophylaxis PrEP and PREP have improved the odds of survival among those living with HIV. However, the anti-retroviral treatments, though effective, are only as effective as early prevention and detection and in cases where patients can adhere to treatment regimens. The mean age of participants (N = 11) was 56.44 (SD = 5.175, range = 47-63). The current study employs qualitative methodology to propose an ecosystems-driven intersectional model to identify resilience and the influence of personal, social, and societal forces shaping the lives of older African American men living with HIV. Findings determine stigma, community violence, and structural barriers to care as crucial stress areas. Participants discussed self-advocacy and family as constituent elements of resilience. Several implications for practice and research emerged. Practice must design and deploy assessment instruments to include exposure to racism and violence, including emotional and structural violence. Practice must include advocacy at the micro, meso, and macro levels. Assessment must also be self-reflexive. Organizational assessment should involve internal and structural reviews of barriers to meeting client preferences.

Adherence and HIV Protection Thresholds for Emtricitabine and Tenofovir Disoproxil Fumarate Preexposure Prophylaxis among Cisgender Women: A Systematic Review

PURPOSE OF REVIEW

Adherence-concentration-efficacy benchmarks have not been fully characterized for cisgender women using emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) oral daily pre-exposure prophylaxis (PrEP) for HIV prevention.

RECENT FINDINGS

We conducted a systematic review to investigate current evidence on the adherence-concentration-efficacy relationship of tenofovir-diphosphate (TFV-DP) derived from FTC/TDF PrEP in dried blood spots (DBS) and peripheral mononuclear cells (PBMC) in cisgender women without HIV, including during pregnancy. We searched for completed and ongoing studies published before May 2024 in PubMed, Embase, Cochrane Library, CINAHL, and clinicaltrial.gov.  Overall, 11 studies assessing adherence benchmarks focusing on (n = 5) or involving (n = 6) cisgender women were included. Women-specific median steady-state TFV-DP concentration for daily dosing ranged from 17 to 51 fmol/106 in PBMC and 1389 to 1685 fmol/punch in DBS in non-pregnant women; 50 to 71 fmol/106 in PBMC and 583 to 965 fmol/punch in DBS in pregnant women; and 618 to 1406 fmol/punch in DBS in postpartum women. DBS TFV-DP levels were 14-43% lower in pregnancy versus postpartum or non-pregnant periods, but PBMC TFV-DP levels appear to be comparable. Clinical and modeling studies demonstrate effective HIV protection for women taking at least four doses/week of oral TDF-based PrEP, and emerging evidence suggests that systemic drug levels are more likely to be predictive of efficacy than local tissue levels at the site of exposure. The preponderance of emerging evidence points to comparable efficacy and similar adherence requirement for women as men among those with detectable drug levels, although there was an indication that the highest achievable efficacy may be reached at a lower adherence level in men than women. In this review, we found evidence that women-specific TFV-DP adherence benchmarks in DBS and PBMC are within range of US-based historical thresholds derived from healthy men and women. Emerging evidence suggests that imperfect but adequate adherence to oral FTC/TDF PrEP with at least four doses/week provides sufficient HIV protection in cisgender women as it does in MSM, but more data are still needed to refine intrinsic achievable efficacy estimates for cisgender women.

Modeling of HIV-1 prophylactic efficacy and toxicity with islatravir shows non-superiority for oral dosing, but promise as a subcutaneous implant

HIV prevention with pre-exposure prophylaxis (PrEP) constitutes a major pillar in fighting the ongoing epidemic. While daily oral PrEP adherence may be challenging, long-acting (LA-)PrEP in oral or implant formulations could overcome frequent dosing with convenient administration. The novel drug islatravir (ISL) may be suitable for LA-PrEP, but dose-dependent reductions inCD 4 + T cell and lymphocyte counts were observed at high doses. We developed a mathematical model to predict ISL pro-drug levels in plasma and active intracellular ISL-triphosphate concentrations after oral vs. subcutaneous implant dosing. Using phase II trial data, we simulated antiviral effects and estimated HIV risk reduction for multiple dosages and dosing frequencies. We then established exposure thresholds where no adverse effects on immune cells were observed. Our findings suggest that implants with 56-62 mg ISL offer effective HIV risk reduction without reducing lymphocyte counts. Oral 0.1 mg daily, 3-5 mg weekly, and 10 mg biweekly ISL provide comparable efficacy, but weekly and biweekly doses may affect lymphocyte counts, while daily dosing regimen offered no advantage over existing oral PrEP. Oral 0.5-1 mg on demand provided> 90 % protection, while not being suitable for post-exposure prophylaxis. These findings suggest ISL could be considered for further development as a promising and safe agent for implantable PrEP.

Drug-drug interactions between gender-affirming hormone therapy and antiretrovirals for treatment/prevention of HIV

Transgender persons face a greater burden of HIV compared to cisgender counterparts. Concerns around drug-drug interactions (DDIs) have been cited as reasons for lower engagement in HIV care and lower pre-exposure prophylaxis (PrEP) uptake among transgender populations. It is therefore imperative for hormone therapy, PrEP and antiretroviral therapy providers to understand the DDI potential between these therapies. Studies of tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) PrEP with feminizing hormone therapies (FHTs) show reduced plasma tenofovir concentrations, but intracellular concentrations of tenofovir-diphosphate are not reduced. Efficacy of PrEP is expected to be maintained despite this interaction. Masculinizing hormone therapies have no effect on tenofovir concentrations but may increase FTC to a nonclinically relevant extent. No interactions between FHT and cabotegravir or tenofovir alafenamide have been demonstrated. Administration of TDF/FTC PrEP has no effect on hormone levels in transmen or transwomen. PrEP is expected to be effective and safe in transpersons and should be provided to high-risk individuals regardless of gender affirming hormone use. Enzyme inducing/inhibiting antiretroviral therapy may decrease or increase, respectively, the concentrations of FHT and masculinizing hormone therapy. Unboosted integrase inhibitors or enzyme neutral non-nucleoside reverse transcriptase inhibitors are not expected to affect and are not affected by gender affirming hormones and can be considered in transmen and transwomen. Overlapping toxicities including weight gain, dyslipidaemia, cardiovascular disease and bone density effects should be considered, and antiretroviral modifications can be made to minimize toxicities. Interactions between supportive care medications should be assessed to avoid chelation interactions and hyperkalaemia.

Unawareness of partner risk factors thwarts implementation of USPSTF recommendations for HIV pre-exposure prophylaxis in primary care

The United States Preventive Services Task Force recommends pre-exposure chemoprophylaxis for persons at high risk of HIV exposure. The optimal screening strategy for at-risk individuals in primary care is not known. We evaluated the strategy of universal screening and discussed challenges to the implementation of this recommendation in primary care. Around 430 of 500 (86%) screening surveys were completed. Mutual monogamy was common but monogamous partners with recent negative HIV testing were uncommon. Likewise, among heterosexually active men and women, inconsistent condom use was common. Such individuals would be on guideline for HIV pre-exposure prophylaxis (PrEP) if their partner was at risk for HIV exposure. None of these potentially at-risk individuals met the criteria for PrEP, but 13% lacked knowledge of their partners' sexual and behavioral risk factors, preventing a clear decision on whether PrEP should be used. Our screen identified no individuals who clearly met the guideline criteria for HIV PrEP. We conclude that universal screening for HIV PrEP in primary care is unlikely to be an efficient strategy; targeted screening is likely more appropriate. Moreover, the 2019 guidelines for heterosexually active men and women rely on information that is often unknown to the patient, which makes these guidelines difficult to implement. Future guidelines should address these problems.

Trajectories of Adherence to Oral Pre-exposure Prophylaxis and Risks of HIV and Sexually Transmitted Infections

Background

Pre-exposure prophylaxis (PrEP) effectiveness is highly dependent on medication adherence, which is associated with differential HIV risks and possibly sexually transmitted infection (STI).

Methods

This retrospective cohort study of PrEP users (01/01/2012-12/31/2021) used the MarketScan database of commercially insured enrollees to examine PrEP adherence trajectory groups' associations with HIV and STI acquisition risks. Distinct PrEP adherence trajectories were identified by group-based trajectory modeling among individuals who used oral PrEP. The primary outcome was HIV acquisition incidence, and secondary was STI rate, compared among trajectory groups. Inverse probability treatment weighting time-varying Cox proportional hazards models assessed HIV acquisition, and Poisson regression models assessed STI.

Results

Among 23 258 oral PrEP users, 4 distinct PrEP adherence patterns were identified: minimal use (10.5% of the cohort), rapidly declining (25.4%), gradually declining (24.3%), and consistently high (39.8%). Compared with the minimal use group, the gradually declining (adjusted hazard ratio [AHR], 0.53; 95% CI, 0.31-0.90) and consistently high (AHR, 0.50; 95% CI, 0.30-0.84) PrEP adherence groups showed decreased HIV incidence risks. Compared with the minimal use group, the rapidly declining (adjusted incidence rate ratio [AIRR], 1.35; 95% CI, 1.07-1.72), gradually declining (AIRR, 1.73; 95% CI, 1.38-2.18), and consistently high (AIRR, 2.06; 95% CI, 1.64-2.58) groups were associated with increased STI risk.

Conclusions

These findings underscore the benefits of continuing and remaining adherent to PrEP and may also inform public health strategies, clinical guidelines, and interventions aimed at maximizing the effectiveness of PrEP in reducing new HIV infections while developing targeted strategies to prevent STIs with PrEP use.

Engagement Along the PrEP Care Continuum Among Men Who Have Sex with Men in China: A Systematic Review and Meta-analysis

Pre-exposure prophylaxis (PrEP), including daily oral, on-demand, and long-acting injectable (LAI), is a promising HIV prevention intervention for men who have sex with men (MSM). We conducted a systematic review on engagement with the PrEP continuum among MSM in China. A total of 756 studies were initially identified and 36 studies were included (N = 26,021). In the 20 studies (N = 13,886) examining PrEP awareness, 32.4% (95% CI: 25.1-40.7) of MSM were aware of PrEP. In the 25 studies (N = 18,587) examining willingness, 54.5% (95% CI: 41.9-66.5) MSM indicated they were willing to use PrEP. The pooled prevalence of PrEP uptake from 9 studies (N = 6,575) was 4.9% (95% CI: 1.4-15.8%), while pooled estimates of adequate adherence from five studies (N = 2,344) among MSM on PrEP was 40.7% (95% CI: 20.0-65.2%). Subgroup analyses suggested studies conducted after 2015 (versus before) tended to report higher awareness and uptake. Awareness was highest for daily oral PrEP, followed by on-demand, and LAI PrEP; willingness to use was highest for LAI PrEP. The operationalization of willingness and adherence constructs varied across studies and complicated the interpretation of pooled estimates. This review revealed gaps in the PrEP care continuum among MSM in China, with relatively low awareness and uptake (in contrast to willingness and adherence) as the major potential barriers to widespread implementation and the need for a unified approach to defining and measuring PrEP outcomes.

A Phase 1 Clinical Trial to Assess the Safety and Pharmacokinetics of a Tenofovir Alafenamide/Elvitegravir Insert Administered Rectally for HIV Prevention

BACKGROUND

On-demand topical products could be an important tool for human immunodeficiency virus (HIV) prevention. We evaluated the safety, pharmacokinetics, and ex vivo pharmacodynamics of a tenofovir alafenamide/elvitegravir (TAF/EVG, 20 mg/16 mg) insert administered rectally.

METHODS

MTN-039 was a phase 1, open-label, single-arm, 2-dose study. Blood, rectal fluid, and rectal tissue were collected over 72 hours following rectal administration of 1 and 2 TAF/EVG inserts for each participant.

RESULTS

TAF/EVG inserts were safe and well tolerated. EVG and tenofovir (TFV) were detected in blood plasma at low concentrations: median peak concentrations after 2 inserts were EVG 2.4 ng/mL and TFV 4.4 ng/mL. Rectal tissue EVG peaked at 2 hours (median, 2 inserts = 9 ng/mg) but declined to below limit of quantification in the majority of samples at 24 hours, whereas tenofovir diphosphate (TFV-DP) remained high >2000 fmol/million cells for 72 hours with 2 inserts. Compared to baseline, median cumulative log10 HIV p24 antigen of ex vivo rectal tissue HIV infection was reduced at each time point for both 1 and 2 inserts (P < .065 and P < .039, respectively).

DISCUSSION

Rectal administration of TAF/EVG inserts achieved high rectal tissue concentrations of EVG and TFV-DP with low systemic drug exposure and demonstrable ex vivo inhibition of HIV infection for 72 hours. Clinical Trials Registration . NCT04047420.

Whole-body distribution of tenofovir, emtricitabine and dolutegravir in non-human primates

BACKGROUND

One major barrier to HIV cure is the persistence of virus, possibly linked to an insufficient antiretroviral drug (ARV) distribution into tissues.

OBJECTIVES

To draw the whole-body distribution of three antiretroviral drugs-tenofovir disoproxil fumarate, emtricitabine and dolutegravir-in non-human primates (NHPs).

METHODS

Eight uninfected NHPs received a single injection of a solution containing the three ARVs. Forty-five different tissues were sampled 24 h after injection.

RESULTS

Median tissue penetration factors (TPFs) were 45.4, 5.8 and 0.5 for tenofovir, emtricitabine and dolutegravir, respectively, and were statistically different between the three ARVs. Tissues were grouped by system, because TPFs were consistent according to these groups, and ranked in order of decreasing TPFs. The digestive system was the system with the highest tissue concentrations. Next came the two main sites of elimination, the liver and the kidney, as well as the tissues of the cardiopulmonary and urinary systems. Then, it was the whole lymphatic system. The next group included the reproductive system, the adipose tissue and the skin. The last two systems were the muscle and the CNS. The intra-tissue variability was rather low with a median coefficient of variation of the concentrations around 15% and no value greater than 80%.

CONCLUSIONS

Overall, this study determines the first whole-body distribution in a validated NHP model. These data have important implications for future preclinical and clinical studies for the development of novel HIV therapies towards an HIV cure.

Longitudinal relationship between pre-exposure prophylaxis motivation and change in adherence among men who have sex with men in Western China

INTRODUCTION

The efficacy of pre-exposure prophylaxis (PrEP) is highly dependent on adherence, and adherence behavior is influenced by motivation. The aim of this study was to explore the longitudinal relationship between PrEP motivation and change in adherence among men who have sex with men (MSM) in Western China.

METHODS

From November 2019 to June 2021, we conducted a PrEP prospective cohort study. Motivation to take medicine was measured by the PrEP Motivation Scale at baseline, and was grouped into different levels of latent categories by Latent Profile Analysis (LPA). A multinomial logistic regression model was used to explore the longitudinal relationship between change in adherence (improvement, decline, no change) and different levels of PrEP motivation.

RESULTS

MSM were divided into two categories of PrEP motivation, a "high motivation group" (n = 506, 69.89%) and a "low motivation group" (n = 218, 30.11%). High PrEP motivation had no significant effect on the change in short-term adherence, however, it contributed to the improvement in long-term adherence [odds ratio (OR) = 3.028 (1.100-8.332), p = 0.031]. The predictive power of the adherence model was significantly enhanced with the addition of the PrEP motivation factor.

CONCLUSIONS

There was a positive correlation between high PrEP motivation at baseline and an improvement in long-term adherence. Surveillance and intervention of PrEP motivation in MSM can increase their adherence, and then promote PrEP efficacy.

A Longitudinal Examination of HIV Risk Perception Accuracy among Sexual Minority Men with History of Childhood Sexual Abuse

Men who have sex with men (MSM) with history of childhood sexual abuse (CSA) are at high risk for HIV acquisition. One reason is posttraumatic responses compromise ability to accurately appraise risk for danger/vulnerability. Health behavior change models and related interventions assume risk perception can be changed in an enduring manner. Given paucity of studies examining how risk perception changes or sustains over time post-intervention, this underlying assumption is not confirmed. Among this particularly high-risk group who struggle with perceiving risk due to trauma-related cognitions, it may be accuracy of risk perception is fluid. The study primarily aimed to examine accuracy of HIV risk perception over time post-HIV prevention behavioral intervention. Leveraging data from a larger RCT, N = 190 MSM in Boston, MA and Miami, FL USA completed a psychosocial baseline assessment, an intervention aimed to increase awareness of personal HIV risk level, then four follow-up assessments three months apart for a year. Linear mixed effect models were used to examine the degree to which accuracy of HIV risk perception (vs. traditional construct of risk perception with no information about accuracy) predicts sex risk behavior over time delineated by between-person (trait level) and within-person (state level) effects. Majority (92%) of participants fluctuated in HIV risk accuracy over time post-intervention. Within-person risk accuracy (one's accuracy at any given timepoint) predicted sex risk behavior (condomless sex not protected by adherent PrEP) over time, but not between-person (one's average of accuracy). Findings have implications for intervention and counseling related to specific HIV prevention strategies.

Assessing Structural Racism and Discrimination Along the Pre-exposure Prophylaxis Continuum: A Systematic Review

Structural racism and discrimination (SRD) is deeply embedded across U.S. healthcare institutions, but its impact on health outcomes is challenging to assess. The purpose of this systematic literature review is to understand the impact of SRD on pre-exposure prophylaxis (PrEP) care continuum outcomes across U.S. populations who could benefit from HIV prevention. Guided by PRISMA guidelines, we conducted a systematic review of the published literature up to September 2023 using PubMed and PsycInfo and included peer-reviewed articles meeting inclusion criteria. At least two authors independently screened studies, performed quality assessments, and abstracted data relevant to the topic. Exposure variables included race/ethnicity and any level of SRD (interpersonal, intra- and extra-organizational SRD). Outcomes consisted of any steps of the PrEP care continuum. A total of 66 studies met inclusion criteria and demonstrated the negative impact of SRD on the PrEP care continuum. At the interpersonal level, medical mistrust (i.e., lack of trust in medical organizations and professionals rooted from current or historical practices of discrimination) was negatively associated with almost all the steps across the PrEP care continuum: individuals with medical mistrust were less likely to have PrEP knowledge, adhere to PrEP care, and be retained in care. At the intra-organizational level, PrEP prescription was lower for Black patients due to healthcare provider perception of higher sex-risk behaviors. At the extra-organizational level, factors such as homelessness, low socioeconomic status, and incarceration were associated with decreased PrEP uptake. On the other hand, healthcare provider trust, higher patient education, and access to health insurance were associated with increased PrEP use and retention in care. In addition, analyses using race/ethnicity as an exposure did not consistently show associations with PrEP continuum outcomes. We found that SRD has a negative impact at all steps of the PrEP care continuum. Our results suggest that when assessing the effects of race/ethnicity without the context of SRD, certain relationships and associations are missed. Addressing multi-level barriers related to SRD are needed to reduce HIV transmission and promote health equity.

Behind Prep Decisions: Understanding User Patterns and Discontinuation Factors in Real-World

This study aimed to characterize the epidemiological aspects of PrEP use and barriers to accessing this prophylaxis. This cross-sectional study was conducted between January 2021 and April 2022, encompassing 140 PrEP users treated at the Testing and Counseling Center (CTA) in Campo Grande, Mato Grosso do Sul. Data on sociodemographic characteristics and factors associated with PrEP discontinuation were obtained using a standardized questionnaire. Most PrEP users were cisgender men (92.00%), predominantly white (51.00%), over 30 years of age (56.50%), homosexual-oriented (76.50%), and had a minimum of 12 years of education (77.50%). Approximately 60.00% admitted to inconsistent condom use in recent sexual encounters, primarily involving anal intercourse. Approximately 88.00% perceived themselves as at risk of contracting STIs in the upcoming year. Regarding new presentation forms, 54.00% indicated a willingness to use "on-demand PrEP," and 92.00% expressed interest in using "injectable PrEP." After 6 months of follow-up, 43.60% (95.00% CI: 35.50-52.00) discontinued PrEP use, primarily due to changes in sexual behavior (38.30%) and difficulties accessing healthcare services (21.28%). This study underscores the need to involve diverse key populations and highlights the significance of PrEP as an ongoing monitoring strategy for HIV/STI prevention in addition to the importance of incorporating new formulations such as daily oral PrEP into the Brazilian National Health System (SUS).

Oral HIV pre-exposure prophylaxis use and resistance-associated mutations among men who have sex with men and transgender persons newly diagnosed with HIV in the Netherlands: results from the ATHENA cohort, 2018 to 2022

BackgroundIn the Netherlands, HIV pre-exposure prophylaxis (PrEP) has been available since 2019. However, the extent of PrEP use prior to HIV diagnosis and development of PrEP-resistance-associated mutations (RAMs) is not known.AimWe assessed prior PrEP use and potential transmission of PrEP RAMs among men who have sex with men (MSM) and transgender persons (TGP) with a new HIV diagnosis in the Netherlands.MethodsData on prior PrEP use between 1 January 2018 and 31 December 2022 were available from the Dutch national ATHENA cohort. We assessed proportion of prior PrEP use, detected PrEP associated RAMs and assessed potential onward transmission of RAMs between 2010 and 2022 using a maximum likelihood tree.ResultsData on prior PrEP use were available for 583/1,552 (36.3%) individuals, with 16% (94/583) reporting prior PrEP use. In 489 individuals reporting no prior PrEP use, 51.5% did not use PrEP due to: low HIV-risk perception (29%), no access (19.1%), personal preference (13.1%), and being unaware of PrEP (19.1%). For PrEP users, 13/94 (13.8%) harboured a M184V/I mutation, of whom two also harboured a K65R mutation. In people with a recent HIV infection, detection of PrEP RAMs increased from 0.23% (2/862) before 2019 to 4.11% (9/219) from 2019. We found no evidence of onward transmission of PrEP RAMs.ConclusionThe prevalence of PrEP-associated RAMs has increased since PrEP became available in the Netherlands. More widespread access to PrEP and retaining people in PrEP programmes when still at substantial risk is crucial to preventing new HIV infections.

HIV Pre-Exposure Prophylaxis

Pre-exposure prophylaxis (PrEP) of human immunodeficiency virus (HIV) represents the most significant breakthrough in the HIV prevention field over the past decade. PrEP is an effective strategy in preventing the transmission of HIV across all populations, providing high adherence. The current PrEP options include oral daily and on-demand tenofovir-based regimens, long-acting injections of cabotegravir, and a 1-month dapivirine vaginal ring. As a component of a multifaceted prevention approach, extensive deployment of PrEP holds the promise to significantly reduce the global HIV epidemic. Nonetheless, barriers still exist in terms of uptake, adherence, and persistence, while disparities in PrEP accessibility remain a concern.

A qualitative study identifying implementation strategies using the i-PARIHS framework to increase access to pre-exposure prophylaxis at federally qualified health centers in Mississippi

BACKGROUND

Mississippi (MS) experiences disproportionally high rates of new HIV infections and limited availability of pre-exposure prophylaxis (PrEP). Federally Qualified Health Centers (FQHCs) are poised to increase access to PrEP. However, little is known about the implementation strategies needed to successfully integrate PrEP services into FQHCs in MS.

PURPOSE

The study had two objectives: identify barriers and facilitators to PrEP use and to develop tailored implementation strategies for FQHCs.

METHODS

Semi-structured interviews were conducted with 19 staff and 17 PrEP-eligible patients in MS FQHCs between April 2021 and March 2022. The interview was guided by the integrated-Promoting Action on Research Implementation in Health Services (i-PARIHS) framework which covered PrEP facilitators and barriers. Interviews were coded according to the i-PARIHS domains of context, innovation, and recipients, followed by thematic analysis of these codes. Identified implementation strategies were presented to 9 FQHC staff for feedback.

RESULTS

Data suggested that PrEP use at FQHCs is influenced by patient and clinic staff knowledge with higher levels of knowledge reflecting more PrEP use. Perceived side effects are the most significant barrier to PrEP use for patients, but participants also identified several other barriers including low HIV risk perception and untrained providers. Despite these barriers, patients also expressed a strong motivation to protect themselves, their partners, and their communities from HIV. Implementation strategies included education and provider training which were perceived as acceptable and appropriate.

CONCLUSIONS

Though patients are motivated to increase protection against HIV, multiple barriers threaten uptake of PrEP within FQHCs in MS. Educating patients and providers, as well as training providers, are promising implementation strategies to overcome these barriers.

Treatment as the Best Prevention: Twice-Yearly Lenacapavir, a Game Changer in Ending the AIDS Epidemic

Despite over four decades of unremitting efforts since the discovery of acquired immunodeficiency syndrome (AIDS)/human immunodeficiency virus (HIV), there remains no cure for HIV nor a vaccine for its prevention [...].

Effectiveness of onsite and online education in enhancing knowledge and use of human immunodeficiency virus pre- and post-exposure prophylaxis

BACKGROUND

Enhancing awareness and use of pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) is vital to curb human immunodeficiency virus (HIV) spread. High-risk behaviors prevalent among sexually transmitted infection clinic outpatients underscore the need for increased PrEP/PEP education in this group.

AIM

To investigate the effects of both onsite and online health education on the knowledge of, and willingness to use, PrEP and PEP among individuals receiving PEP services.

METHODS

Participants were drawn from a cohort study on PEP service intervention at an STD/AIDS outpatient clinic in designated HIV/AIDS hospitals in Beijing, conducted from January 1 to June 30, 2022. Health education was provided both onsite and online during follow-up. Surveys assessing knowledge of, and willingness to use, PrEP/PEP were administered at baseline and again at 24 wk post-intervention.

RESULTS

A total of 112 participants were enrolled in the study; 105 completed the follow-up at week 24. The percentage of participants with adequate knowledge of, and willingness to use, PrEP significantly increased from 65.2% and 69.6% at baseline to 83.8% and 82.9% at the end of the intervention (both P < 0.05). Similarly, those with adequate knowledge of, and willingness to use, PEP increased from 74.1% and 77.7% at baseline to 92.4% and 89.5% at week 24 (P < 0.05). Being between 31 years and 40 years of age, having a postgraduate degree or higher, and reporting a monthly expenditure of RMB 5000 or more were found to be significantly associated with knowledge of PrEP and PEP (both P < 0.05).

CONCLUSION

The findings show that both onsite and online health education significantly improved the knowledge of, and increased willingness to use, PrEP and PEP in individuals utilizing PEP services.

Prevalence and Risk Factors of Cytomegalovirus Among Men Having Sex With Men Enrolled in a Pre-Exposure Prophylaxis Study

Risk factors for cytomegalovirus (CMV) acquisition in men having sex with men remain unclear. Seroprevalence, incidence, risk factors and shedding of CMV were analyzed among participants enrolled in the HIV pre-exposure prophylaxis IPERGAY-ANRS trial. Among the 417 participants tested, 382 were seropositive at baseline (prevalence of 91.6%; 95%CI[88.5-94.1]) and 10/35 seroconverted during the study (incidence of 17.1 per 100 person-years; 95%CI[8.2-31.3]). A high number of sexual partners was independently associated with CMV seroprevalence. Shedding among CMV-seroconverters was reported for 6/9 and 2/9 at the oral and anal levels, respectively. Our data supports transmission of CMV during sexual contacts.

Study part of the ANRS-IPERGAY Clinical trial

ClinicalTrials.gov number, NCT01473472.

Predictors of PrEP Retention and Attrition in an Urban Publicly Funded Safety-net Specialty Clinic

Pre-exposure prophylaxis (PrEP) is an effective tool for human immunodeficiency virus (HIV) prevention. The purpose of this study is to identify correlates of PrEP retention using patient data from an urban, publicly funded safety-net clinic in Washington, DC. Cox proportional hazards regression, logistical regression, and survival curves were used to assess the association of age, gender, race/ethnicity, insurance, number of partners, and sexually transmitted infection (STI) diagnosis at PrEP initiation with time on PrEP. From August 2016-December 2020, 1,126 people were prescribed PrEP - patients were mostly Black (44.8%) or Latinx (30.4%) and identified as cisgender men (84.6%). Half had no insurance (49.1%), with the remaining patients reporting private (28.9%) or public (21.5%) insurance. Age at PrEP prescription ranged from 15 to 66 with 80% being 20 to 39 years. For the 87.7% (n = 987) of patients who discontinued PrEP, mean PrEP time was 158 days and median was 28 days. The highest rates of discontinuation were observed within the first month with 44.3% discontinuing by day 30, 52.3% by 3 months, and 73.2% by 1 year. Cisgender women, transgender persons, and those younger than 30 years were more likely to discontinue PrEP. Latinx and patients with less than 3 male partners in the last 90 days were less likely to discontinue PrEP. We demonstrated a high level of PrEP uptake among populations disproportionally affected by HIV. Future analyses are needed to examine ways of reducing barriers to PrEP initiation and improving PrEP adherence.

An enhanced cross-sectional HIV incidence estimator that incorporates prior HIV test results

Incidence estimation of HIV infection can be performed using recent infection testing algorithm (RITA) results from a cross-sectional sample. This allows practitioners to understand population trends in the HIV epidemic without having to perform longitudinal follow-up on a cohort of individuals. The utility of the approach is limited by its precision, driven by the (low) sensitivity of the RITA at identifying recent infection. By utilizing results of previous HIV tests that individuals may have taken, we consider an enhanced RITA with increased sensitivity (and specificity). We use it to propose an enhanced estimator for incidence estimation. We prove the theoretical properties of the enhanced estimator and illustrate its numerical performance in simulation studies. We apply the estimator to data from a cluster-randomized trial to study the effect of community-level HIV interventions on HIV incidence. We demonstrate that the enhanced estimator provides a more precise estimate of HIV incidence compared to the standard estimator.

The challenges of Chile to achieve control the HIV/AIDS pandemic the year 2030: A review

Chile is contending with the highest rates of new human immunodeficiency virus (HIV) cases in both Latin America and globally, despite substantial ongoing investments in treatment. This comprehensive study, derived from PUBMED and Google searches, ANID data, and various organizational reports, highlights key areas for improvement. Over the past decade, Chile's annual infection rate has risen, signaling an urgent need for detailed analysis and effective solutions. The study includes 44 references, comprising 32 scientific articles and 12 reports from entities like the WHO and the Pan American Health Organization. Data was meticulously collected through diverse means, such as scientific congresses, meetings with authorities, and direct data requests. Fourteen critical points are identified for addressing the HIV epidemic in Chile, spanning from legislative reforms to enhanced prevention campaigns. Key recommendations include universal diagnosis, decentralized healthcare, the availability of self-tests, and a focus on mental health and the impact of migration. Despite Chile's strong economic indicators, factors such as inadequate sexual education, outdated legislation, and centralized diagnostic processes contribute to the persistent increase in new cases. The study underscores the pressing need for enhanced investment in prevention policies. Chile faces significant challenges in meeting the 90/90/90 targets, yet there is optimism in aiming for the 95/95/95 strategy by 2030. Achieving success requires a global commitment, an emphasis on prevention, and collaborative efforts among authorities, healthcare providers, and patients. Overcoming these identified barriers is essential for Chile to reach its ambitious goal and ultimately end the HIV epidemic.

Correlates of oral pre-exposure prophylaxis cessation among men who have sex with men in China: implications from a nationally quantitative and qualitative study

BACKGROUND

Several studies have demonstrated the population-level effectiveness of oral PrEP in reducing the risk of HIV infection. However, oral PrEP utilization among MSM in China remains below 1%. While existing literature has primarily focused on oral PrEP preference and willingness, there is limited exploration of the underlying factors contributing to oral PrEP cessation in China. This study aims to fill this gap by investigating the factors associated with oral PrEP cessation among MSM in China.

METHODS

Assisted by MSM community organizations, we collected 6,535 electronic questionnaires from 31 regions across China, excluding Taiwan, Hong Kong, and Macau. The questionnaire focused on investigating MSM's awareness, willingness, usage, and cessation of oral PrEP. Additionally, 40 participants were randomly chosen for key informant interviews. These qualitative interviews aimed to explore the reasons influencing MSM discontinuing oral PrEP.

RESULTS

We eventually enrolled 6535 participants. Among the 685 participants who had used oral PrEP, 19.70% (135/685) ceased oral PrEP. The results indicated that individuals spending > ¥1000 on a bottle of PrEP (aOR = 2.999, 95% CI: 1.886-4.771) were more likely to cease oral PrEP compared to those spending ≤ ¥1000. Conversely, individuals opting for on-demand PrEP (aOR = 0.307, 95% CI: 0.194-0.485) and those using both daily and on-demand PrEP (aOR = 0.114, 95% CI: 0.058-0.226) were less likely to cease PrEP compared to those using daily PrEP. The qualitative analysis uncovered eight themes influencing oral PrEP cessation: (i) High cost and low adherence; (ii) Sexual inactivity; (iii) Lack of knowledge about PrEP; (iv) Trust in current prevention strategies; (v) Poor quality of medical service and counseling; (vi) PrEP stigma; (vii) Partner and relationship factors; (viii) Access challenges.

CONCLUSIONS

The cessation of oral PrEP among MSM in China is associated with various factors, including the cost of oral PrEP medication, regimens, individual perception of HIV risk, stigma, and the quality of medical services. It is recommended to provide appropriate regimens for eligible MSM and develop tailored combinations of strategies to enhance PrEP awareness and acceptance among individuals, medical staff, and the MSM community. The findings from this study can support the refinement of HIV interventions among MSM in China, contributing to efforts to reduce the burden of HIV in this population.

Understanding the influence of the microbiome on childhood infections

INTRODUCTION

The microbiome is known to have a substantial impact on human health and disease. However, the impacts of the microbiome on immune system development, susceptibility to infectious diseases, and vaccine-elicited immune responses are emerging areas of interest.

AREAS COVERED

In this review, we provide an overview of development of the microbiome during childhood. We highlight available data suggesting that the microbiome is critical to maturation of the immune system and modifies susceptibility to a variety of infections during childhood and adolescence, including respiratory tract infections, Clostridioides difficile infection, and sexually transmitted infections. We discuss currently available and investigational therapeutics that have the potential to modify the microbiome to prevent or treat infections among children. Finally, we review the accumulating evidence that the gut microbiome influences vaccine-elicited immune responses among children.

EXPERT OPINION

Recent advances in sequencing technologies have led to an explosion of studies associating the human microbiome with the risk and severity of infectious diseases. As our knowledge of the extent to which the microbiome influences childhood infections continues to grow, microbiome-based diagnostics and therapeutics will increasingly be incorporated into clinical practice to improve the prevention, diagnosis, and treatment of infectious diseases among children.

Perceptions and Acceptance of a Prophylactic Vaccine for Human Immunodeficiency Virus (HIV): A Qualitative Study

BACKGROUND

Despite advances in human immunodeficiency virus (HIV) prevention methods, such as the advent of pre-exposure prophylaxis (PrEP), the number of people with newly acquired HIV remains high, particularly in at-risk groups. A prophylactic HIV vaccine could contribute to reduced disease prevalence and future transmission and address limitations of existing options, such as suboptimal long-term adherence to PrEPs.

METHODS

This qualitative study aimed to capture perceptions towards and acceptance of prophylactic HIV vaccination in three adult populations in the United States: the general population, 'at-risk' individuals (e.g. men who have sex with men, transgender individuals, gender-nonconforming individuals, and individuals in a sexual relationship with a person living with HIV), and parents/caregivers of children aged 9-17 years. Interviews were conducted with 55 participants to explore key drivers and barriers to HIV vaccine uptake, and a conceptual model was developed.

RESULTS

The sample was diverse; participants were 51% female, aged 20-57 years (mean 37 years), 33% with high school diploma as highest education level, and identified as White (42%), Black or African American (35%), of Hispanic, Latino, or Spanish origin (22%), or other races/ethnicities (8%) [groupings are not mutually exclusive]. Perceptions were influenced by individual, interpersonal, community, institutional, and structural factors. Overall, 98% of participants thought vaccination would be beneficial in preventing HIV. Key considerations/barriers included perceived susceptibility, i.e. whether participants felt there was a risk of contracting HIV (discussed by 90%); the clinical profile of the vaccine (e.g. the adverse effect profile [98%], and vaccine efficacy [85%], cost [73%] and administration schedule [88%]); and concerns around potential vaccine-induced seropositivity (VISP; 62%). Stigma was not found to be an important barrier, with a general view that vaccination status was personal. Participants in the 'at-risk' group were the most likely to accept an HIV vaccine (70%). Unique concerns in the subgroups included how a potential vaccine's clinical profile compared with PrEP, voiced by those receiving/considering PrEP, and considerations of children's views on the topic, voiced by parents/caregivers.

CONCLUSIONS

Understanding these factors could help develop HIV vaccine research strategies and contribute toward public health messaging to support future HIV vaccination programs.

Breaking barriers: Assessing pre-exposure prophylaxis awareness and willingness to use in the Lebanese community

BACKGROUND

In the evolving HIV landscape, the Middle East and Northern Africa (MENA) grapples with data gaps, hindering the 95-95-95 targets. Lebanon, despite progress, falls short. Our study addresses Pre-exposure Prophylaxis (PrEP) gaps for effective HIV prevention.

METHODS

Surveying 410 participants via snowball sampling and an online questionnaire, we analyzed data with chi-square and regression over 5 months for insights into PrEP awareness and readiness.

RESULTS

Summarizing the pivotal statistical outcomes of the study, 22.2% reported awareness of PrEP, showcasing diverse knowledge levels about its purpose and usage. Out of them, 57.1% expressed a willingness to use it; while a mere 5.5% have utilized it. The study reveals diverse demographic profiles, with age influencing PrEP awareness and willingness to use. Positive correlations exist between PrEP discussions within social circles, increased information availability, and elevated willingness. Financial considerations and accessibility at pharmacies emerge as critical determinants, guiding the development of targeted interventions.

CONCLUSIONS

This analysis emphasizes tailored education, community initiatives, and policy enhancements to address PrEP challenges in Lebanon. Guiding public health initiatives, our study considers age, social dynamics, education, and accessibility in HIV prevention.

Factors Associated with PrEP Persistence and Loss of Follow-Up: A 5-Year Historic Cohort

OBJECTIVE

HIV Pre-Exposure Prophylaxis (PrEP) has been used in France since 2016. Its effectiveness is no longer to be demonstrated. However, follow-up and adherence remain the main pitfalls. The main objective of this study was to identify factors associated with persistence or loss of PrEP follow-up.

DESIGN

An historic cohort of PrEP users was compiled from the database of consultations in the Indre-et-Loire dedicated sexual health centers (CeGIDD) from June 2016 to June 2021.

METHODS

Kaplan-Meier curves were performed to compare the group of persistent PrEP users to the discontinuation group. Factors associated with PrEP discontinuation were identified using Cox modelling, considering time-dependent variables. Final variables included in the model were selected based on the Akaike Information Criterion (AIC) and clinical relevance.

RESULTS

Over the period, 568 PrEP users were included in the cohort. Median follow-up was 2.3 years. A quarter of users were lost to follow-up within 3 months after PrEP initiation. Sexual risk reduction AIDS community-based support (HR = 0.65[0.42;0.99]), being in a couple (HR = 0.51[0.38;0.68]), and history of syphilis (HR = 0.57[0.40;0.81]) were significantly associated with persistence of follow-up. Remote consultations (HR = 2.74[1.63;4.61]), chemsex practices (HR = 2.01[1.29;3.14]), and side effects (HR=1.72[1.03;2.88]) were significantly associated with a loss of follow-up.

CONCLUSION

These results suggest that more sexual risk reduction AIDS community-based counseling could be a key, necessary for supporting PrEP users in their follow-up pathway. Indeed, AIDS community-based support could be used to build a basis for developing safe pathways. Remote consultations could represent a response to the issue of access to PrEP. To create a significant impact on global HIV incidence, the PrEP offer must be extended, and at-risk PrEP users supported to maintain PrEP use.

Concordance between daily diary reported pre-exposure prophylaxis intake and intraerythrocytic tenofovir diphosphate in the Amsterdam Pre-exposure Prophylaxis demonstration project

OBJECTIVE

We assessed the association and concordance between self-reported oral pre-exposure prophylaxis (PrEP) intake in a diary app and intraerythrocytic drug metabolite concentrations.

DESIGN

AMPrEP was a prospective demonstration study providing daily and event-driven PrEP to MSM in Amsterdam, the Netherlands (2015-2020).

METHODS

Participants could record their PrEP intake in a diary app. Dried blood spots (DBS) were taken at 6, 12, 24, and 48 months and analysed for tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) concentrations. We included TFV-DP measurements preceded by diary completion on at least 90% of days in the 6 weeks prior. We examined the association between self-reported PrEP intake (i.e. number of pills) and TFV-DP concentrations using tobit regression with a random intercept per participant. We also calculated concordance between categorized PrEP intake (i.e. <2, 2-3, 4-6 or 7 pills per week) and categorized TFV-DP concentrations (i.e. <350, 350-699,700-1249 or ≥1250 fmol/punch) using weighted Cohen's kappa. Last, we calculated concordance between self-reported recent PrEP intake (yes/no, in past 2 days) and quantifiability of FTC-TP (yes/no) using Cohen's kappa.

RESULTS

Seven hundred and fifty-nine DBS measurements from 282 MSM were included. Self-reported PrEP intake was strongly and positively associated with TFV-DP concentration ( β  = 0.77, 95% CI = 0.70-0.84, P  < 0.0001). Concordance between categorized PrEP intake and TFV-DP concentration was moderate ( κ  = 0.44, 95% CI = 0.39-0.50). Concordance between self-reported recent PrEP intake and FTC-TP quantifiability was perfect ( κ  = 0.83, 95% CI 0.76-0.90).

CONCLUSION

Self-reported PrEP intake in a diary app is strongly correlated with actual use, and therefore reliable for comparing PrEP adherence between groups. Still, suboptimal criterion validity according to clinically relevant categories warrants caution when assessing 6-week reported adherence for individuals.

Psychiatry and Family Medicine Residents' Likelihood of Prescribing HIV Pre-exposure Prophylaxis to Patients With Mental Illness and HIV Vulnerability

BACKGROUND

People living with mental illness (PLMI) experience disproportionately high incidence of and vulnerability to HIV. Pre-exposure prophylaxis (PrEP) is an effective and safe HIV prevention method, but data regarding prescription to PLMI are lacking. Psychiatrists may serve as important points of access for PrEP prescription for PLMI.

METHODS

We conducted a vignette-based study of residents in psychiatry and family medicine (FM) to assess likelihood of prescribing PrEP and assumptions about the fictional patient. Participants were randomized to one of five vignettes in which the patients' psychiatric diagnosis was varied (schizophrenia on long-acting injectable or oral antipsychotic, bipolar disorder, major depression) or a control vignette without a psychiatric diagnosis.

RESULTS

A total of 439 residents participated. We found that high percentages of psychiatry (96.8%) and FM (97.4%) residents were aware of PrEP. High percentages of psychiatry (92.0%-98.1%) and FM (80.8%-100%) residents reported that PrEP was indicated for all patient conditions. Family medicine residents were more likely to prescribe PrEP to all experimental conditions than psychiatry residents. There was no difference in likelihood of prescribing to the control condition without a psychiatric diagnosis. The belief that PrEP prescription was out of scope of practice was greater among psychiatry residents.

CONCLUSIONS

A majority of psychiatry residents responded that PrEP was indicated for an array of patients with psychiatric diagnoses. However, psychiatry residents were broadly less likely to prescribe PrEP to patients with these diagnoses. The high percentage of psychiatry residents who reported that PrEP was indicated for all patients suggests that additional training is needed to facilitate PrEP prescription by psychiatrists.

Willingness to Use Long-Acting Injectable Cabotegravir and Associated Factors Among Men Who Have Sex with Men in Guangxi, China

Cabotegravir (CAB-LA), the first long-acting injectable pre-exposure prophylaxis (PrEP), has been approved for use in the USA and is not currently on the market in China. However, willingness to use CAB-LA and associated factors among men who have sex with men (MSM) have not yet been evaluated in China. A cross-sectional study was conducted in Guangxi, China, in 2022 recruiting 1,006 MSM. Their mean age was 30.2 years, 74.2% had college or above education, and 48.6% had a monthly income between 3,000 and 5,999 Chinese yuan (CNY). Most (73.4%) had previously heard of PrEP while few (8.3%) had ever used this type of preventative medication. Willingness to use CAB-LA was 79.8% and was positively associated with eight variables: younger age, being married to a woman, having a low monthly income, having six or more male partners in the past six months, having only regular male partners in the past month, having a high perceived risk of HIV infection, and history of using PrEP. Ten other variables were not significantly associated with willingness to use CAB-LA. Among 894 participants who were willing to use or did not definitely reject using CAB-LA, the main concerns about CAB-LA were its side effects (90.2%), efficacy (63.6%), and high cost (58.2%). Only 14.7% were willing to pay more than 1,200 CNY (~US$180) every two months to use CAB-LA. The preferred injection places were centers for disease control facilities, hospitals, and social organizations. Many (89.0%) said that they would recommend CAB-LA to their male sexual partners. We conclude that willingness to use CAB-LA was high among MSM in Guangxi. However, implementation of CAB-LA faces tough challenges due to its high cost and the low use of PrEP. Peer education may play a large role in the implementation of CAB-LA in China.

Identifying Best Practices for Increasing HIV Pre-exposure Prophylaxis (PrEP) Use and Persistence in the United States: A Systematic Review

A qualitative systematic review was conducted to evaluate pre-exposure prophylaxis (PrEP) interventions, describe characteristics of best practices for increasing PrEP use and persistence, and explore research gaps based on current PrEP interventions. We searched CDC's Prevention Research Synthesis (PRS) Project's cumulative HIV database (includes CINAHL, EMBASE, Global Health, MEDLINE, PsycInfo, and Sociological Abstracts) to identify PrEP intervention studies conducted in the U.S., published between 2000 and 2022 (last searched January 2023). Eligibility criteria include studies that evaluated PrEP interventions for persons testing negative for HIV infection, or for healthcare providers who prescribed PrEP; included comparisons between groups or pre/post; and reported at least one relevant PrEP outcome. Each eligible intervention was evaluated on the quality of study design, implementation, analysis, and strength of evidence (PROSPERO registration number: CRD42021256460). Of the 26 eligible interventions, the majority were focused on men who have sex with men (n = 18) and reported PrEP adherence outcomes (n = 12). Nine interventions met the criteria for Best Practices (i.e., evidence-based interventions, evidence-informed interventions). Five were digital health interventions while two implemented individual counseling, one offered motivational interviewing, and one provided integrated medical care with a PrEP peer navigator. Longer intervention periods may provide more time for intervention exposure to facilitate behavioral change, and engaging the community when developing, designing and implementing interventions may be key for effectiveness. For digital health interventions, two-way messaging may help participants feel supported. Research gaps included a lack of Best Practices for several populations (e.g., Black persons, Hispanic/Latino persons, persons who inject drugs, and women of color) and evidence for various intervention strategies (e.g., interventions for promoting provider's PrEP prescription behavior, peer support). These findings call for more collaborative work with communities to develop interventions that work and implement and disseminate Best Practices for increasing PrEP use and persistence in communities.

Incidence and factors associated with PrEP discontinuation in France

OBJECTIVES

HIV pre-exposure prophylaxis (PrEP) is effective in preventing HIV, but some seroconversions occur due to poor adherence or PrEP discontinuation. Our objective was to estimate the incidence of PrEP discontinuation and describe the reasons and factors associated with discontinuations.

METHODS

A retrospective cohort was conducted in three French hospitals between January 2016 and June 2022. PrEP users who attended at least twice within 6 months during study period were included and followed up until December 2022. The incidence rate of PrEP discontinuation was estimated by censoring lost to follow up individuals. Factors associated with PrEP discontinuations were identified using a multivariate Cox model.

RESULTS

A total of 2785 PrEP users were included, with 94% men and 5% transgender people. Median age was 35 years. By December 2022, 653 users had stopped PrEP (24%). The incidence rate was 10.8 PrEP discontinuations for 100 person-years (PY). The main causes of discontinuation were being in a stable relationship (32%), and not judging the treatment useful anymore (12%). Individuals who discontinued PrEP were younger [<29, HR = 1.45 (1.17-1.80)], and more likely to be women [HR = 2.44 (1.50-3.96)] or sex workers [HR = 1.53 (0.96-2.44)]. They were more likely to report PrEP side effects [HR = 2.25 (1.83-2.77)] or ≥2 sexually transmitted infections [HR = 1.87 (1.53-2.27)] during the last year.

CONCLUSION

The incidence of PrEP discontinuations was quite low compared to rates observed in other cohorts. Users who stopped PrEP were sometimes still exposed to HIV, emphasizing the need for targeted interventions to prepare and support PrEP discontinuations and limit seroconversion risk.

Dynamics of HIV PrEP use and coverage during and after COVID-19 in Germany

BACKGROUND

Pre-exposure prophylaxis (PrEP) with oral emtricitabine/tenofovir disoproxil (FTC/TDF) proved highly efficient in preventing HIV. Since 09/2019, FTC/TDF-PrEP is covered by health insurances in Germany, if prescribed by licensed specialists. However, methods to longitudinally monitor progress in PrEP implementation in Germany are lacking.

METHODS

Utilizing anonymous FTC/TDF prescription data from 2017-2021, we developed a mathematical model to disentangle HIV-treatment from PrEP prescriptions, as well as to translate PrEP prescriptions into number of PrEP users. We used the model to estimate past- and future PrEP uptake dynamics, to predict coverage of PrEP needs and to quantify the impact of COVID-19 on PrEP uptake on a national and regional level.

RESULTS

We identified significant (p<0.01) decelerating effects of the first- and second COVID-19-lockdown on PrEP uptake in 04/2020 and 12/2020. We estimated 26,159 (CI: 25,751-26,571) PrEP users by 12/2021, corresponding to 33% PrEP coverage of people in need. We projected 64,794 (CI: 62,956-66,557) PrEP users by 12/2030, corresponding to 81% PrEP coverage. We identified profound regional differences, with high PrEP coverage and uptake in metropoles and low coverage in more rural regions.

CONCLUSIONS

Our approach presents a comprehensive solution to monitor and forecast PrEP implementation from anonymous data and highlighted that the COVID-19 pandemic significantly decelerated PrEP uptake in Germany. Moreover, slow PrEP uptake in rural areas indicate that structural barriers in PrEP care, education or information exist that may hamper the goal of ending the AIDS epidemic by 2030.

Breakthrough Acute HIV Infections among Pre-Exposure Prophylaxis Users with High Adherence: A Narrative Review

Pre-exposure prophylaxis (PrEP) is a pivotal intervention among HIV prevention strategies. We aimed to narratively revise the topic of HIV acute infection in the setting of PrEP exposure with a focus on diagnostic options, clinical features, and future PrEP perspectives, with a particular focus on users with high adherence to PrEP. We searched the main databases (PubMed, Embase, and Scopus) with the keywords "PrEP" or "Pre-Exposure Prophylaxis" and "HIV" or "PLWH" and "breakthrough" or "acute infection" or "primary infection". We included all randomized clinical trials and non-experimental studies (both case reports and observational studies) ever published. In the present narrative review, we revise the diagnostic challenges related to HIV diagnosis in the setting of PrEP and the clinical characteristics and symptoms of breakthrough infections. We discuss the management of acute HIV infection during PrEP and the new challenges that arise from the use of long-acting drugs for PrEP. Our review underlines that although extremely rare, HIV seroconversions are still possible during PrEP, even in a context of high adherence. Efforts to promptly identify these events must be included in the PrEP follow-up in order to minimize the chance of overlooked HIV breakthrough infections and thus exposure to suboptimal concentrations of antiretrovirals.

Low clinical impact of HIV drug resistance mutations in oral pre-exposure prophylaxis: a systematic review and meta-analysis

INTRODUCTION

Despite the widespread use of pre-exposure prophylaxis (PrEP) in preventing human immunodeficiency virus (HIV) transmission, scant information on HIV drug resistance mutations (DRMs) has been gathered over the past decade. This review aimed to estimate the pooled prevalence of pre-exposure prophylaxis and its two-way impact on DRM.

METHODS

We systematically reviewed studies on DRM in pre-exposure prophylaxis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 guidelines. PubMed, Cochrane, and SAGE databases were searched for English-language primary studies published between January 2001 and December 2023. The initial search was conducted on 9 August 2021 and was updated through 31 December 2023 to ensure the inclusion of the most recent findings. The registration number for this protocol review was CRD42022356061.

RESULTS

A total of 26,367 participants and 562 seroconversion cases across 12 studies were included in this review. The pooled prevalence estimate for all mutations was 6.47% (95% Confidence Interval-CI 3.65-9.93), while Tenofovir Disoproxil Fumarate/Emtricitabine-associated drug resistance mutation prevalence was 1.52% (95% CI 0.23-3.60) in the pre-exposure prophylaxis arm after enrolment. A subgroup analysis, based on the study population, showed the prevalence in the heterosexual and men who have sex with men (MSM) groups was 5.53% (95% CI 2.55-9.40) and 7.47% (95% CI 3.80-12.11), respectively. Notably, there was no significant difference in the incidence of DRM between the pre-exposure prophylaxis and placebo groups (log-OR = 0.99, 95% CI -0.20 to 2.18, I2 = 0%; p = 0.10).

DISCUSSION

Given the constrained prevalence of DRM, the World Health Organization (WHO) advocates the extensive adoption of pre-exposure prophylaxis. Our study demonstrated no increased risk of DRM with pre-exposure prophylaxis (p > 0.05), which is consistent with these settings. These findings align with the previous meta-analysis, which reported a 3.14-fold higher risk in the pre-exposure prophylaxis group than the placebo group, although the observed difference did not reach statistical significance (p = 0.21).

CONCLUSIONS

Despite the low prevalence of DRM, pre-exposure prophylaxis did not significantly increase the risk of DRM compared to placebo. However, long-term observation is required to determine further disadvantages of extensive pre-exposure prophylaxis use. PROSPERO Number: CRD42022356061.