Impact Of Pre-exposure Prophylaxis Research Articles

Impact of national commissioning of pre-exposure prophylaxis (PrEP) on equity of access in England: a PrEP-to-need ratio investigation

ObjectivesHIV pre-exposure prophylaxis (PrEP) is highly effective in preventing HIV acquisition. In England, NHS availability was limited to participants of the PrEP Impact Trial until late 2020. Some key populations...

Sexual pleasure and HIV-related worry in female sex workers on oral pre-exposure prophylaxis in south-western Uganda.

Female sex workers (FSWs) contribute disproportionately to HIV transmission in Uganda, and pre-exposure prophylaxis (PrEP) is effective in preventing HIV among cisgender women. Psychological factors are important for PrEP uptake, but few studies have examined psychosocial changes due to PrEP use in Uganda. In 2021, we recruited 524 FSWs in three Trans-African Highway towns and four fishing communities in south-western Uganda. We conducted structured interviews among women who were attending routine PrEP follow-up visits in six health units. Bivariable and multivariable modified regression using a robust covariance matrix estimator were used to identify factors associated with experiencing increased sexual pleasure and less worry about HIV because of PrEP. Overall, 80.9% participants reported that sex was more pleasurable because of taking PrEP. There were statistical trends for sex being more pleasurable when taking PrEP or when having condomless sex with casual paying partners (aPR=1.19, 95% CI=1.07-1.32, P=0.001). Almost three-quarters of the participants (76.3%) were less worried about getting HIV because of PrEP. Condomless sex with casual paying partners (aPR=1.17, 95% CI=1.05-1.31, P=0.032, P=0.003) and being On PrEP for the past 1-2years (aPR=1.18, 95% CI=1.00-1.38, P=0.032) was significantly associated with HIV-related worry (aPR=1.17, 95% CI=1.05-1.31, P=0.032, P=0.003)Conclusions:We found a positive impact of PrEP in Ugandan FSWs on two key psychosocial dimensions: (1) more pleasurable sex; and (2) less worry about acquiring HIV. Interventions aiming to increase PrEP uptake may find it useful to focus on psychosocial dimensions.

Population-level effectiveness of pre-exposure prophylaxis for HIV prevention among men who have sex with men in Montréal (Canada): a modelling study of surveillance and survey data.

HIV pre-exposure prophylaxis (PrEP) has been recommended and partly subsidized in Québec, Canada, since 2013. We evaluated the population-level impact of PrEP on HIV transmission among men who have sex with men (MSM) in Montréal, Québec's largest city, over 2013-2021. We used an agent-based mathematical model of sexual HIV transmission to estimate the fraction of HIV acquisitions averted by PrEP compared to a counterfactual scenario without PrEP. The model was calibrated to local MSM survey, surveillance, and cohort data and accounted for COVID-19 pandemic impacts on sexual activity, HIV prevention, and care. PrEP was modelled from 2013 onwards, assuming 86% individual-level effectiveness. The PrEP eligibility criteria were: any anal sex unprotected by condoms (past 6 months) and either multiple partnerships (past 6 months) or multiple uses of post-exposure prophylaxis (lifetime). To assess potential optimization strategies, we modelled hypothetical scenarios prioritizing PrEP to MSM with high sexual activity (≥11 anal sex partners annually) or aged ⩽45 years, increasing coverage to levels achieved in Vancouver, Canada (where PrEP is free-of-charge), and improving retention. Over 2013-2021, the estimated annual HIV incidence decreased from 0.4 (90% credible interval [CrI]: 0.3-0.6) to 0.2 (90% CrI: 0.1-0.2) per 100 person-years. PrEP coverage among HIV-negative MSM remained low until 2015 (<1%). Afterwards, coverage increased to a maximum of 10% of all HIV-negative MSM, or about 16% of the 62% PrEP-eligible HIV-negative MSM in 2020. Over 2015-2021, PrEP averted an estimated 20% (90% CrI: 11%-30%) of cumulative HIV acquisitions. The hypothetical scenarios modelled showed that, at the same coverage level, prioritizing PrEP to high sexual activity MSM could have averted 30% (90% CrI: 19%-42%) of HIV acquisitions from 2015-2021. Even larger impacts could have resulted from higher coverage. Under the provincial eligibility criteria, reaching 10% coverage among HIV-negative MSM in 2015 and 30% in 2019, like attained in Vancouver, could have averted up to 63% (90% CrI: 54%-70%) of HIV acquisitions from 2015 to 2021. PrEP reduced population-level HIV transmission among Montréal MSM. However, our study suggests missed prevention opportunities and adds support for public policies that reduce PrEP barriers, financial or otherwise, to MSM at risk of HIV acquisition.

HIV pre-exposure prophylaxis and its implementation in the PrEP Impact Trial in England: a pragmatic health technology assessment

HIV pre-exposure prophylaxis (PrEP) is highly effective in preventing HIV acquisition. To enable routine commissioning of PrEP in England, we aimed to establish population need, duration of need, PrEP uptake, and duration of use in attendees of sexual health services (SHS) in England. The Impact Trial was a prospective, open-label, single-arm, multicentre trial conducted at 157 SHS across England between Oct 13, 2017, and July 12, 2020. Clinicians assessed HIV-negative attendees for their risk of HIV acquisition to identify those who were eligible to participate and receive either daily or event-based oral PrEP (tenofovir disoproxil maleate with emtricitabine), as appropriate. Eligible participants were aged 16 years or older, considered HIV-negative on the day of enrolment, and willing to adhere to the trial procedures. Non-trial attendees are mutually exclusive of trial participants and included SHS attendees who were not recruited to the Impact Trial at any point. They include HIV-negative individuals aged 16 years or older who attended a participating SHS at least once after recruitment at that SHS had begun and before Feb 29, 2020. The main outcomes assessed were PrEP need, uptake, and use, and HIV and sexually transmitted infection (STI) incidence. Data are presented up to Feb 29, 2020, before the introduction of COVID-19 control measures. The study is registered with ClinicalTrials.gov, NCT03253757. In this analysis, we include 21 356 of 24 268 participants enrolled before Feb 29, 2020. 20 403 participants (95·5%) were men who have sex with men (MSM). Uptake of PrEP among SHS attendees clinically assessed and coded as eligible was 21 292 (57·1%) of 37 289. 18 400 trial participants had at least one post-enrolment visit and a median of 361 days of follow-up (IQR 143-638); 14 039 (75·9%) of these had enough PrEP prescribed to provide protection for 75% of their follow-up time. Among MSM, HIV incidence was 0·13 (95% CI 0·08-0·19) per 100 person-years in trial participants (27 seroconversions) and 0·95 (95% CI 0·88-1·03) per 100 person-years in non-trial attendees (587 seroconversions; proportionate reduction of 86·8%, 95% CI 80·2-91·6). 18 607 bacterial STIs were recorded (incidence 68·1 per 100 person-years in trial participants who were MSM). 4343 (24·4%) MSM participants were diagnosed with two or more STIs, accounting for 14 800 (79·5%) of all 18 607 diagnoses. PrEP need was higher than initially estimated by an expert stakeholder group. The high proportion of follow-up time protected by PrEP suggests that the need for protection persisted throughout trial participation for most participants. HIV incidence among MSM trial participants was low. The large unmet need for PrEP suggests that greater provision is required to maximise the potential of a national programme. The high incidence of bacterial STIs among participants, concentrated within a subgroup of PrEP users, presents an opportunity for tailored STI control measures. NHS England.

“Sex without fear”: exploring the psychosocial impact of oral HIV pre-exposure prophylaxis on gay men in England

Gay, bisexual, and other men who have sex with men (GBMSM) experience a high prevalence of psychosocial health problems, such as harmful substance use and depression, as well as being disproportionately affected by HIV. HIV Pre-Exposure Prophylaxis (PrEP) may provide psychosocial benefits beyond its intended purpose of reducing HIV infection. We explore the psychosocial impact of oral PrEP use on gay men in England using qualitative data from the PROUD study. From February 2014 to January 2016, semi-structured in-depth interviews were conducted with 40 gay men and one trans woman. Participants were purposively recruited based on trial arm allocation, adherence, and sexual risk behaviours. By removing HIV risk from sex, PrEP improves users’ wellbeing by reducing HIV-related anxiety and internalised stigma and increasing HIV prevention self-efficacy, sexual pleasure, and intimacy. In turn, these psychological changes may influence behaviour in the form of greater sexual freedom, reduced harmful drug use, and more protective sexual health behaviours. However, PrEP may create internal conflict for some gay men, due to its disruption of social norms around condom use and its perceived influence on their sexual behaviour leading to reduced condom self-efficacy. These findings provide a baseline of PrEP’s psychosocial impact amongst some of the first PrEP users in England and supports calls to consider the psychosocial impact of PrEP in prescribing guidelines.

Impact of Sars-CoV-2 Prophylaxis with Tixagevimab-Cilgavimab in High-Risk Patients with B-Cell Malignancies: A Single-Center Retrospective Study.

Severe Acute Respiratory Syndrome CoronaVirus‐2 (SARS‐CoV‐2) infection can result in different clinical manifestations (COVID-19), starting from asymptomatic disease to life threatening respiratory insufficiency. Onco-haematologic patients are at higher risk to develop severe COVID-19. In particular, patients affected by lymphoproliferative diseases, given the impaired cell-mediated and antibody-mediated immunity and treatment toxicity, develop more often a symptomatic and a more serious disease of Covid-19. Various therapeutic and prophylactic agents are being used against COVID‐19 such as antiviral drugs, vaccines and antiviral S‐protein monoclonal antibodies. Pre-exposure prophylaxis with AZD442/Evusheld (tixagevimab-cilgavimab) may be a complementary strategy to decrease the incidence or severity of COVID-19 for patients with B-cell malignancies. Tixagevimab-cilgavimab is a combination of two monoclonal antibodies that bind SARS-CoV-2 spike protein and inhibits the attachment to the surface of cells, preventing viral entry in the cell and COVID-19 development. In the setting of hematology real-life, few data are available on the impact of pre-exposure prophylaxis, given the multiple factors involved in the clinical behavior of SARS-CoV-2 . Our aim was to evaluate the clinical benefit and the safety of this strategy at our center.

Use of Tenofovir Alafenamide Fumarate for HIV Pre-Exposure Prophylaxis and Incidence of Hypertension and Initiation of Statins

Pre-exposure prophylaxis (PrEP) is an important tool for preventing HIV infection. However, PrEP's impact on cardiometabolic health is understudied. To examine the risk of incident hypertension and statin initiation among adult (age ≥18 years) health plan members starting PrEP with tenofovir alafenamide fumarate (TAF) compared with propensity score-matched adults taking tenofovir disoproxil fumarate (TDF). This retrospective cohort study used electronic health records (EHRs) from Kaiser Permanente Southern California. Adult members starting PrEP in Kaiser Permanente Southern California between October 2019 and May 2022 were included. Propensity score matching with multiple imputation (50 matched data sets) was conducted to generate 1 TAF:4 TDF matched data sets with balanced baseline covariates. PrEP initiation with either TAF or TDF during the study period. Incident hypertension and statin initiation within 2 years of PrEP initiation were ascertained through blood pressure and outpatient pharmacy records, respectively. Risk differences and odds ratios (ORs) were estimated using logistic regression and g-computation. A total of 6824 eligible individuals were identified (mean [SD] age, 33.9 [10.3] years; 6618 [97%] male). This pool was used to generate 2 cohorts without baseline hypertension or statin use for matching (hypertension: n = 5523; statin: n = 6149) In both cohorts, those starting PrEP with TAF were older and were more likely to be non-Hispanic White compared with those starting with TDF. In matched analysis adjusting for baseline covariates, TAF use was associated with elevated risk of incident hypertension (TAF: n = 371; risk difference, 0.81 [95% CI, 0.12-1.50]; OR, 1.64 [95% CI, 1.05-2.56]). TAF use was also associated with elevated risk of statin initiation (TAF: n = 382; risk difference, 0.85 [95% CI, 0.37-1.33]; OR, 2.33 [95% CI, 1.41-3.85]). Subgroup analyses restricted to individuals 40 years and older at PrEP initiation showed similar results with larger risk difference in statin initiation (risk difference, 4.24 [95% CI, 1.82-6.26]; OR, 3.05 [95% CI, 1.64-5.67]). In this study of people taking PrEP, TAF use was found to be associated with higher incident hypertension and statin initiation compared with TDF use, especially in those 40 years or older. Continued monitoring of blood pressure and lipids for TAF users is warranted.

Long-acting refillable nanofluidic implant confers protection against SHIV infection in nonhuman primates.

The impact of pre-exposure prophylaxis (PrEP) on slowing the global HIV epidemic hinges on effective drugs and delivery platforms. Oral drug regimens are the pillar of HIV PrEP, but variable adherence has spurred development of long-acting delivery systems with the aim of increasing PrEP access, uptake, and persistence. We have developed a long-acting subcutaneous nanofluidic implant that can be refilled transcutaneously for sustained release of the HIV drug islatravir, a nucleoside reverse transcriptase translocation inhibitor that is used for HIV PrEP. In rhesus macaques, the islatravir-eluting implants achieved constant concentrations of islatravir in plasma (median 3.14 nM) and islatravir triphosphate in peripheral blood mononuclear cells (median 0.16 picomole per 106 cells) for more than 20 months. These drug concentrations were above the established PrEP protection threshold. In two unblinded, placebo-controlled studies, islatravir-eluting implants conferred 100% protection against infection with SHIVSF162P3 after repeated low-dose rectal or vaginal challenge in male or female rhesus macaques, respectively, compared to placebo control groups. The islatravir-eluting implants were well tolerated with mild local tissue inflammation and no signs of systemic toxicity over the 20-month study period. This refillable islatravir-eluting implant has potential as a long-acting drug delivery system for HIV PrEP.

The relationship of PrEP beliefs to perceived personal, interpersonal and structural benefits and barriers to PrEP use in women who inject drugs

BackgroundWomen who inject drugs (WWID) have significant biological, behavioral, and gender-based barriers to accessing HIV prevention services, including Pre-Exposure Prophylaxis (PrEP) medication. Little is known about how beliefs about PrEP impact both perceived barriers and benefits of PrEP use and how they may be related to the decision-making process.MethodsSurveys were conducted with 100 female clients of a large syringe services program in Philadelphia, Pennsylvania. The sample was categorized into three groups based on mean PrEP beliefs scores using terciles: accurate beliefs, moderately accurate beliefs, and inaccurate beliefs. Oneway ANOVA tests were used to compare groups by perceived benefits and barriers to PrEP, drug use stigma, healthcare beliefs, patient self-advocacy, and intention to use PrEP.ResultsParticipants had a mean age of 39 years (SD 9.00), 66% reported being White, 74% finished high school, and 80% reported having been homeless within the past 6 months. Those with the most accurate PrEP beliefs reported highest intent to use PrEP and were more likely to agree that benefits of PrEP included it preventing HIV and helping them “feel in charge”. Those with inaccurate beliefs were more likely to strongly agree that barriers, such as fear of reprisal from a partner, potential theft, or feeling they “might get HIV anyway”, were reasons not to use PrEP.ConclusionsResults indicate perceived personal, interpersonal and structural barriers to PrEP use are associated with accuracy of beliefs is, pointing to important intervention targets to increase uptake among WWID.

Developing evidence-informed indicators to monitor HIV pre-exposure prophylaxis programmes across EU/EEA countries: a multi-stakeholder consensus.

Several countries in the European Union (EU) and European Economic Area (EEA) established and/or scaled up HIV pre-exposure prophylaxis (PrEP) programmes between 2016 and 2023. Data on PrEP programmes' performance and effectiveness in reaching those most in need will be needed to assess regional progress in the roll-out of PrEP. However, there is a lack of commonly defined indicators for routine monitoring to allow for minimum comparability. We propose a harmonised PrEP monitoring approach for the EU/EEA, based on a systematic and evidence-informed consensus-building process involving a broad and multidisciplinary expert panel. We present a set of indicators, structured along relevant steps of an adapted PrEP care continuum, and offer a prioritisation based on the degree of consensus among the expert panel. We distinguish between 'core' indicators deemed essential for any PrEP programme in the EU/EEA, vs 'supplementary' and 'optional' indicators that provide meaningful data, yet where experts evaluated their feasibility for data collection and reporting as very context-dependent. By combining a standardised approach with strategic opportunities for adaptation and complementary research, this monitoring framework will contribute to assess the impact of PrEP on the HIV epidemic in Europe.

Determinants of Preexposure Prophylaxis Cascade Among Sexual and Gender Minorities in Nigeria.

Preexposure prophylaxis (PrEP) is effective in preventing human immunodeficiency virus (HIV) infection among sexual and gender minorities (SGMs). We evaluated the characteristics associated with engagement in 7 steps of the PrEP cascade among SGMs in Nigeria. Sexual and gender minorities without HIV from the Abuja site of TRUST/RV368 cohort who were surveyed on awareness of and willingness to use PrEP were approached for PrEP initiation upon availability of oral daily PrEP. To understand gaps in the uptake of oral daily PrEP, we categorized the HIV PrEP cascade as (i) education about PrEP, (ii) interest in PrEP, (iii) successful contact, (iv) appointment scheduled, (v) appointment attendance, (vi) PrEP initiation, and (vii) plasma protective levels of tenofovir disoproxil fumarate. Multivariable logistic regression models were used to determine factors associated with each of the 7 steps in the HIV PrEP cascade. Of 788 participants, 718 (91.1%) showed interest in taking oral daily PrEP every day and/or after a sexual act, 542 (68.8%) were successfully contacted, 433 (54.9%) scheduled an appointment, 409 (51.9%) attended a scheduled appointment, 400 (50.8%) initiated oral daily PrEP, and 59 (7.4%) had protective levels of tenofovir disoproxil fumarate. Of initiators of PrEP, 23 (5.8%) seroconverted at a rate of 13.9 cases/100 person-years. Better social support, larger network density, and higher education were associated with engagement in 4 to 5 components of the cascade. Our data highlight a gap between willingness and actual PrEP use. Despite PrEP's effectiveness in preventing HIV, the optimal impact of PrEP for SGMs in sub-Saharan Africa will require multifaceted approaches that combine social support, education, and destigmatization.

2088. Real-World Geographic Variations of HIV Diagnosis Rates among Individuals Prescribed and not Prescribed Oral HIV Pre-Exposure Prophylaxis (PrEP) Regimens in the United States

Abstract Background Declines in the diagnoses of new HIV infections have been reported in geographic areas with higher uptake of PrEP among persons who would benefit from PrEP (PWBP). In the present analysis, we examined the rate of new HIV diagnoses in PWBP prescribed PrEP and those not prescribed PrEP in order to understand the current and potential impact of PrEP in differing geographies. Methods We estimated the rate of new HIV infections among PWBP not prescribed PrEP with a previously described model (Mera et al. 2019) using a combination of published reports and a claims database. HIV rates for individuals prescribed F/TAF or F/TDF (including brand and generic) for PrEP between 10/3/2019 (F/TAF approval) and 6/30/2021 were analyzed from claims data. For those prescribed PrEP, new infections included new HIV diagnosis or addition of HIV treatment within 10 days of PrEP discontinuation. Results Overall, the US HIV diagnosis rate was 61% lower among PWBP prescribed PrEP (1.33 per 100-person year [95%CI: 1.24 – 1.42]) compared to those not prescribed PrEP (3.38 [3.35 – 3.42]). New HIV diagnosis rates by state among PWBP not prescribed PrEP ranged from 0.41 (0.22 – 0.78) in Vermont to 9.96 (9.53 – 11.54) in Mississippi (Figure). The Southern US had the highest regional HIV diagnosis rate among PWBP not prescribed PrEP (4.20 [4.14 - 4.26], Table). HIV diagnosis rates by state among PWBP prescribed PrEP were lower, ranging from 0 to 2.40 (0.05 – 4.75). Eleven states had a greater than 85% lower HIV diagnosis rate among PWBP prescribed PrEP versus those who were not prescribed PrEP, and the greatest differences in diagnosis rates by PrEP prescription status were observed in the Southeastern US states. Figure:The estimated rates of new HIV diagnosis (per 100 person-years) among PWBP who were not prescribed PrEP in 2019 (A) and those prescribed PrEP from 10/3/2019 to 6/30/2021 (B) in the United States.Table:Regional variations of new HIV diagnosis rates among PWBP who were not prescribed PrEP in 2019 and those prescribed PrEP from 10/3/2019 to 6/30/2021 in the United States. Conclusion This study suggests that substantial reductions in HIV diagnosis rates have occurred in people prescribed PrEP in the US. We found large geographic variations in HIV diagnosis rates, with the largest differences by PrEP prescription status occurring in the Southeast US, underscoring the need for PrEP expansion and its potential impact on the HIV epidemic in that region. Furthermore, our findings demonstrate an approach of estimating HIV rates for PWBP prescribed and those not prescribed PrEP, which may be useful in supporting targeted delivery of HIV prevention services in the US. Disclosures Li Tao, MD, PhD, Gilead Sciences: Employee|Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds|Gilead Sciences: Stocks/Bonds Jen Thorburn, n/a, Gilead Sciences: Grant/Research Support Amanda Kong, DrPH, Gilead Sciences: Grant/Research Support Debra Irwin, PhD, Gilead Sciences: Grant/Research Support Christoph C. Carter, MD, PhD, Gilead Sciences: Employee|Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds|Gilead Sciences: Stocks/Bonds Moupali Das, MD, Gilead Sciences: Employee|Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds|Gilead Sciences: Stocks/Bonds Julie Paone, MPH, Gilead Sciences: Grant/Research Support.

Brief Report: Use of Pre-Exposure Prophylaxis to Prevent Rapid HIV Transmission Among People Who Inject Drugs in Rural Counties in the United States: A Modeling Study.

Despite recent HIV outbreaks among people who inject drugs (PWID) in nonurban US settings, syringe service programs (SSP) are often inaccessible in these communities. Furthermore, pre-exposure prophylaxis (PrEP) awareness and coverage for PWID is limited. We aimed to model the impact of PrEP on HIV transmission among PWID in a rural setting. Using a calibrated agent-based model, we simulated HIV transmission in an adult population (n = 14,573 agents) in Scott County, Indiana between 2015 and 2024. We modeled PrEP eligibility according to CDC guidelines for PWID. PrEP coverage increased by 15% points in the range 10%-70%. Two counterfactual scenarios were modeled: Unrestricted access for PWID and PrEP for SSP attendees . We calculated the number of new HIV infections and number of person-years on PrEP per averted infection. In the status quo scenario, 153 (95% Simulation Interval: 85, 259) new HIV infections occurred among PWID over 10 years. Compared with the status quo, 40% PrEP coverage resulted in 25% fewer HIV infections in the Unrestricted access for PWID scenario and 10% fewer HIV infections in the PrEP for SSP attendees scenario. The PYPAI was 21 and 43 in the Unrestricted access for PWID and PrEP for SSP attendees scenarios, respectively. Our modeling suggests that PrEP provides substantial benefit to PWID in rural US communities, with fewer restrictions on access providing the greatest effect. Control of HIV outbreaks will require expansion of public health interventions that meet the needs of all individuals.

The impact of prevention-effective PrEP use on HIV incidence: a mathematical modelling study.

Models that project the impact and cost-effectiveness of HIV pre-exposure prophylaxis (PrEP) must specify how PrEP use aligns with HIV exposure. We hypothesized that varying PrEP use according to individual-level partnership dynamics rather than prioritization to population subgroups based on average risk will result in larger incidence reductions and greater efficiency. We used an individual-based network transmission model calibrated to HIV dynamics in Eswatini to simulate PrEP use among individuals ages 15-34 between 2022 and 2031 under two paradigms of PrEP delivery: "Risk Group" and "Partnership." In the "Risk Group" paradigm, we varied PrEP coverage by risk groups (low, medium and high) defined by average partnership frequency and concurrency. In the "Partnership" paradigm, all individuals are potentially eligible for PrEP, but we assumed use occurs only during partnerships and varied prioritization by partner HIV status (no prioritization to high prioritization with HIV-positive partners). We calculated person-time on PrEP and incidence relative to a no PrEP scenario and estimated efficiency as the person-years of PrEP needed to avert one additional infection (NNT). In the Risk Group paradigm, restricting PrEP to the high-risk group was the most efficient (NNT = 17), but the number of infections averted was limited by the small size of the high-risk group. Expanding PrEP use to all risk groups averted up to three times more infections but with lower efficiency (NNT = 202). PrEP use under the Partnership paradigm was 2-6 times more efficient (NNT = 33-102) than the Risk Group paradigm with all groups eligible for PrEP. A 33% reduction in incidence among 15- to 34-year-olds was achieved at 46% (95% CI: 39-52%) PrEP coverage in the Risk Group paradigm and 6% (95% CI: 5-7%) to 17% (95% CI: 14-20%) in the Partnership paradigm. Modelling PrEP use based on risk groups resulted in a sharp trade-off between PrEP efficiency and impact, whereas PrEP use predicated on partnerships resulted in much higher efficiency for widespread PrEP availability. Model estimates of PrEP impact and cost-effectiveness in generalized epidemics are strongly influenced by assumptions about how PrEP use aligns with individual-level HIV exposure heterogeneity.

A Mathematical Model for HIV/AIDS Under Pre-Exposure and Post-Exposure Prophylaxis

HIV/AIDS has a strong impact on society, the economy, and health. Early diagnosis of cases, adherence to treatment, and prevention are important factors in controlling the epidemic in the population. In this paper, we present a new mathematical model for the study of HIV/AIDS transmission. Our model is stratified in men and women, to account for the main forms of sexual transmission homosexual and heterosexual relationships, and infectiousness in the HIV and AIDS stages. In addition, in the construction of the model, we take into account the influence of Pre-Exposure Prophylaxis (PrEP) and Post-Exposure Prophylaxis (PEP) to study the impact of these implementations, diagnosis, and effectiveness of treatment based on viral load undetectability. We study the basic reproduction number by subpopulation (men and women) and general. Working by subpopulations allows us to study men who have sex with men who have a strong impact on virus transmission. Also, we study the infection-free equilibrium points due to their relationship with the basic reproduction number and demonstrate the global stability by subpopulation and general. To explore our model, we performed computational simulations on a scenario designed with data from the literature and assumed, studying the influence of the parameters associated with the use of PrEP, PEP, and undetectability on the basic reproduction number by varying them individually and jointly. We concluded that in women the basic reproduction number is always lower than unity and that in men the parameter associated with the undetectability of the viral load in HIV men has a strong influence on the dynamics. We also address the impact of PrEP, PEP, and undetectability in HIV and AIDS on the compartments, considering different scenarios varying the parameters jointly and independently and by sex which show difficulty in reducing women with AIDS. The scenario that showed the best results in the reduction of the number of HIV and AIDS cases was when the parameters associated with undetectability in HIV and AIDS men and women take the 90-90-90 that is proposed in the World Health Organization (WHO) strategy.

Pharmacists and the next generation of HIV pre-exposure prophylaxis

The use of pre-exposure prophylaxis (PrEP) has curtailed transmission of human immunodeficiency virus (HIV) in most industrialized nations. Despite the availability of PrEP, HIV infections continue to occur. Access and adherence are major limitations to PrEP. Long-acting injectable antiretroviral agents are now being added to the HIV armamentarium. Long-acting agents offer the advantage of less frequent dosing with intramuscular administration versus oral dosing. Cost, injection site pain, and needle hesitancy may be detriments to the use of these agents in certain patients. More studies are needed to completely discern the role of various products and future long-acting agents as options for PrEP. Even when we consider their limitations, long-acting agents may provide an eventual opportunity to transform the delivery of PrEP. Pharmacists should be aware of the potential impact of PrEP and the advantages and disadvantages of these new long-acting agents. In addition, pharmacists should proactively advocate for and contribute to PrEP expansion efforts.

EPH84 Effectiveness of HIV Pre-Exposure Prophylaxis for Prevention of HIV: A Retrospective Cohort Analysis

Pre-exposure prophylaxis (PrEP) is an integral tool in reducing new HIV infections in national prevention strategies in the United States. Despite the efficacy of PrEP demonstrated in clinical trials, low adherence and high discontinuation rates in clinical practice may threaten the public health impact of PrEP. We assessed real-world effectiveness of PrEP on the prevention of HIV infection in clinical practice.

HIV pre-exposure prophylaxis: assessment of acceptability among members of HIV serodiscordant/serostatus unknown couples.

Pre-exposure prophylaxis (PrEP) is effective in preventing HIV infection but is not yet widely available in resource-limited settings such as the Dominican Republic. We aimed to ascertain PrEP acceptability among people living with HIV in the Dominican Republic who are part of HIV serodiscordant partnerships and understand relationships between PrEP acceptability, HIV stigma, and intimate partner violence.Methods: A cross-sectional survey of people in care for HIV infection included acceptability-related questions and assessments of HIV stigma and intimate partner violence. We also explored the expected impact of PrEP on HIV disclosure rates and fertility intentions.Results: Of the 100 participants, 74% had been in their current partnership for >1year; 38% had not disclosed to their partner; 29% reported condomless sex, and 23% reported sex with multiple partners. PrEP was highly acceptable with 84% of participants saying they were "very likely" to offer PrEP to their partner if available and 21% stating it would allow them to have more children. Of those who had not disclosed to their partner, 71% stated PrEP would help them do so. No relationship was found between PrEP acceptability, HIV stigma, and intimate partner violence. However, higher than expected rates of PrEP acceptability limited the power of these analyses.Conclusion: Pre-exposure prophylaxis was considered to be highly acceptable among people living with HIV in the Dominican Republic who are part of serodiscordant partnerships.

The worldwide burden of HIV in transgender individuals: An updated systematic review and meta-analysis.

Transgender individuals are at risk for HIV. HIV risks are dynamic and there have been substantial changes in HIV prevention (e.g., pre-exposure prophylaxis [PrEP]). It is thus time to revisit HIV prevalence and burden among transgender individuals. The objective of this systematic review and meta-analysis was thus to examine worldwide prevalence and burden of HIV over the course of the epidemic among trans feminine and trans masculine individuals. We conducted an updated systematic review by searching PsycINFO, PubMed, Web of Science, and Google Scholar, for studies of any research design published in in a peer-reviewed journal in any language that reported HIV prevalence among transgender individuals published between January 2000 and January 2019. Two independent reviewers extracted the data and assessed methodological quality. We then conducted a meta-analysis, using random-effects modelling, to ascertain standardized prevalence and the relative burden of HIV carried by transgender individuals by country and year of data collection, and then by geographic region. We additionally explored the impact of sampling methods and pre-exposure prophylaxis (PrEP). Based on 98 studies, overall standardized HIV prevalence over the course of the epidemic, based on weights from each country by year, was 19.9% (95% CI 14.7% - 25.1%) for trans feminine individuals (n = 48,604) and 2.56% (95% CI 0.0% - 5.9%) for trans masculine individuals (n = 6460). Overall OR for HIV infection, compared with individuals over age 15, was 66.0 (95% CI 51.4-84.8) for trans feminine individuals and 6.8 (95% CI 3.6-13.1) for trans masculine individuals. Prevalence varied by geographic region (13.5% - 29.9%) and sampling method (5.4% - 37.8%). Lastly, PrEP effects on prevalence could not be established. Trans feminine and trans masculine individuals are disproportionately burdened by HIV. Their unique prevention and care needs should be comprehensively addressed. Future research should further investigate the impact of sampling methods on HIV prevalence, and monitor the potential impact of PrEP.

Modelling the geographical spread of HIV among MSM in Guangdong, China: a metapopulation model considering the impact of pre-exposure prophylaxis.

Men who have sex with men (MSM) make up the majority of new human immunodeficiency virus (HIV) diagnoses among young people in China. Understanding HIV transmission dynamics among the MSM population is, therefore, crucial for the control and prevention of HIV infections, especially for some newly reported genotypes of HIV. This study presents a metapopulation model considering the impact of pre-exposure prophylaxis (PrEP) to investigate the geographical spread of a hypothetically new genotype of HIV among MSM in Guangdong, China. We use multiple data sources to construct this model to characterize the behavioural dynamics underlying the spread of HIV within and between 21 prefecture-level cities (i.e. Guangzhou, Shenzhen, Foshan, etc.) in Guangdong province: the online social network via a gay social networking app, the offline human mobility network via the Baidu mobility website, and self-reported sexual behaviours among MSM. Results show that PrEP initiation exponentially delays the occurrence of the virus for the rest of the cities transmitted from the initial outbreak city; hubs on the movement network, such as Guangzhou, Shenzhen, and Foshan are at a higher risk of ‘earliest’ exposure to the new HIV genotype; most cities acquire the virus directly from the initial outbreak city while others acquire the virus from cities that are not initial outbreak locations and have relatively high betweenness centralities, such as Guangzhou, Shenzhen and Shantou. This study provides insights in predicting the geographical spread of a new genotype of HIV among an MSM population from different regions and assessing the importance of prefecture-level cities in the control and prevention of HIV in Guangdong province.This article is part of the theme issue ‘Data science approach to infectious disease surveillance’.