bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-527. A Scoping Review of HIV Pre-exposure Prophylaxis for Indigenous Peoples: Understanding Barriers and Facilitators to PrEP Access, Use and Adherence
Authors: Lim Timothy , Swidrovich Jaris 
Published: January 2025

Abstract

Background
Indigenous Peoples in Canada, which include First Nations, Métis, and Inuit, experience disproportionately higher incidences of human immunodeficiency virus (HIV) infection compared to settler Canadians. Pre-Exposure Prophylaxis (PrEP) involves the daily use of antiretroviral drugs to prevent HIV transmission to HIV-negative people. When taken as prescribed, PrEP can reduce one's risk of getting HIV from sex by over 90% and by more than 70% among people who inject drugs. While PrEP awareness has increased over the years, reasons for its lack of uptake in Indigenous populations remains unknown. A scoping review was done to understand the current literature available how Indigenous Peoples in Canada, United States, Australia and New Zealand conceptualize PrEP.

Methods
We searched electronic databases (Pubmed, Ovid Medline, i-Portal, and Native Health Databases) for studies published between January 2012 and December 2023 for articles using variants of the search terms “Pre-Exposure Prophylaxis” and “Indigenous” . Studies were included if they discussed barriers and/or facilitators to PrEP awareness, interest, uptake, or continuation among Indigenous Peoples. Studies were independently screened by two authors.

Results
Results were synthesized narratively. Of 50 citations identified, 3 studies were eligible for inclusion. Four themes arose from the literature - all of which discussed barriers to PrEP: (1) limited Indigenous engagement and representation in research, (2) stigma and cultural barriers, (3) resource constraints and (4) geographical and socioeconomic barriers to PrEP.

Conclusion
There is a paucity of literature exploring barriers and facilitators to PrEP access, use and adherence in Indigenous Peoples. Given the colonial history and violence that Indigenous Peoples faced and continue to face in western countries such as Canada, United States, Australia and New Zealand, greater attention to culturally safe and trauma informed interventions will likely improve PrEP awareness and use in Indigenous populations.

Disclosures
All Authors: No reported disclosures
P-571. Assessment of Failures of Long-Acting Cabotegravir and Rilpivirine in a Real-World Treatment Setting
Authors: Yared Nicholas F , Gudipati Smitha , Payne Shannon , Brar Indira 
Published: January 2025

Abstract

Background
Cabotegravir (CAB) + rilpivirine (RPV) is the first complete long-acting all injectable (LAI) antiretroviral therapy (ART). While well-tolerated with low risk of virologic failure (VF), understanding reasons for CAB + RPV (CAR) discontinuation in a real-world setting was the objective of our study, so as to better define appropriate patients for LAI.

Methods
We performed a retrospective cohort study to assess CAR failures. CAR failure was defined as regimen discontinuation after receipt of at least one CAR dose due to either virologic failure (VF) or side effects. VF was defined as viral load (VL) ≥ 30 copies/mL on 2 occasions at least 4 weeks apart. Genotypes incorporated detection of drug resistance mutations (DRMs) at frequency &lt; 10%. We included PWH at Henry Ford Health who were virologically suppressed on their current ART and switched to CAR on or before March 2023. Demographics, clinical characteristics, and outcomes were extracted from the electronic medical record (Table 1).

Results
Of the 58 PWH initiating CAR, 46 had HIV VL testing available at 12 months after initiation of CAR and 45/46 PWH (97.8%) were undetectable (&lt; 30 copies/mL). Five PWH failed CAR: 2/5 secondary to injection site reactions and 3/5 due to VF with new resistance (Table 2). Among those with VF, they had been living with HIV for a mean of 20 years and all had BMI &gt; 30 kg/m2. One had a pre-existing G140R DRM (1.2% frequency) and developed the E138K NNRTI and Q148R INSTI DRMs ( &gt; 10% frequency). A second patient developed the Y188L and E138E/K NNRTI and Q148K INSTI DRMs ( &gt; 10% frequency). The third patient with history of oral NNRTI use developed the M230I and E138E/K NNRTI DRMs ( &gt;10% frequency).

Conclusion
In our clinic more patients (8.6%) discontinued CAR than had been reported in randomized clinical trials. While the clinical significance of &lt; 10% DRMs is unclear, one patient with pre-existing G140R &lt; 10% DRM developed VF despite on-time injections leading to loss of NNRTI and INSTI class efficacy. Previous studies have shown that the detection of drug-resistant &lt; 10% DRMs in NNRTI significantly increases the risk of treatment failure. Larger studies are needed to determine the impact of HIV-1 &lt; 10% DRMs for other classes of ARTs, such as INSTIs, as this may have a big impact while evaluating appropriateness of a patient for CAR.

Disclosures
Indira Brar, MD, Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Gilead: Honoraria|Merck: Grant/Research Support|ViiV Healthcare: Grant/Research Support|ViiV Healthcare: Honoraria
P-572. Real-World Experience with Long-Acting Injectable Cabotegravir/Rilpivirine (CAB/RPV LA) in an Academic Medical Center
Authors: Semeniuk Oleksandr , Ogilvy Alexander , Ruiz Maria Elena , Lucar Jose A , Roberts Afsoon , Ware Chelsea , Siegel Marc O 
Published: January 2025

Abstract

Background
Since the approval of CAB/RPV LA, over 50 patients followed in the MFA Infectious Diseases clinic have transitioned to long-acting injectable CAB/RPV. Several patients were found to have low-level viremia despite no documented resistance to either component of CAB/RPV LA. We investigated the incidence of low-level viremia and associated risk factors in this patient population.

Methods
We reviewed the charts of all patients who received at least 3 doses of CAB/RPV LA and evaluated the incidence of HIV viral loads (VL) ≥50 copies. Those patients were categorized into 3 groups: a) blips – isolated VL of 51-200 copies that resolved on subsequent test, b) low-level viremia – sustained VL of 51-200 copies on consecutive tests, c) virologic failure – VL over 200 copies. For all patients, we reviewed age, gender, race, weight, BMI, HIV VL, CD4 count/CD4% before initiating CAB/RPV LA, prior antiretroviral therapy, history of prior resistance mutations, comorbid conditions (diabetes, kidney disease, chronic hepatitis, cancer), tobacco use, and statin use.

Results
51 patients met inclusion criteria for the study. Seven patients (13.7%) had blips, one patient (2%) had low-level viremia, and one patient (2%) had evidence of virologic failure, although this was not sustained on repeat testing. Four patients discontinued treatment due to side effects or social reasons. The only statistically significant risk factor for subsequent viremia was the presence of viremia prior to initiation of CAB/RPV LA: 2.7 % (1/37) in the group with no VL≥50 after the initiation of therapy vs. 33.3% (3/9) in the group that later had blips or viremia, p=0.02. There was also a tendency to the higher incidence of viremia in patients with diabetes mellitus although it did not reach statistical significance (7.1% vs. 33.4%, P=0.06).

Conclusion
CAB/RPV LA is a valuable option for HIV management in the outpatient setting. We documented a relatively small incidence of viral blips and low-level viremia in our population, with statistical significance seen in those with detectable viremia at initiation of CAB/RPV LA. Of the patients included in the analysis, there was no sustained virologic failure confirmed by viral load retest and resistance testing.

Disclosures
All Authors: No reported disclosures
P-582. Long-term effectiveness and tolerability of Dolutegravir/Lamivudine in Korea: 3 year follow up
Authors: Seong Jae Eun , Ahn Sangmin , Han Min , Lee Yongseop , Ah Lee Jung , Ho Kim Jung , Ahn Jin Young , Jeong Su Jin , Su Ku Nam , Choi Jun Yong , Yeom Joon-sup 
Published: January 2025

Abstract

Background
Many studies have revealed the real-world effectiveness and tolerability of Dolutegravir/Lamivudine (DTG/3TC). However, most studies were conducted in Western countries, and data from Asian countries are still lacking; in particular, the results from long-term use have not been reported in Asian countries. As DTG/3TC has been introduced and is becoming increasingly widespread in Asia, it is necessary to investigate the maintenance rate, reasons for discontinuation, long-term effectiveness, and metabolic parameter changes.

Methods
We performed a retrospective cohort study with adult people with HIV treated with DTG/3TC specific combination at a tertiary hospital in Korea. Among them, those who were followed up for more than 36 months were included. Both treatment-naïve and those who switched from other antiretroviral therapies to DTG/3TC were included. Baseline characteristics, DTG/3TC maintenance rates, effectiveness, and metabolic parameters changes over 36 months were investigated.

Results
From July 2020 to April 2024, 305 people with HIV started DTG/3TC. Among them, 134 people with HIV followed for more than 36 months were included (16 treatment-naïve and 118 switching). Most were male (N=126, 94%), and the median age was 45.5 years. There were no cases of switching from DTG/3TC to other ARTs during the 36-month follow-up after starting DTG/3TC. All of the treatment-naïve group maintained HIV RNA &lt; 50 copies/mL from 6 to 36 months after starting DTG/3TC. The rate of HIV RNA &lt; 50 copies/mL at the 36 months in the switching group was 99.2% (117/118). In the treatment-naïve group, CD4 cell count increased from a median of 494 cells/uL at baseline to 795 cells/uL at 36 months (p=0.005). During the 36-month follow-up, there were no significant changes in lipid profile and body weight in both treatment-naïve and switching groups except for an increase in HDL cholesterol in the switching group (from median 45 mg/dL at baseline to median 49 mg/dL at 36-month, p=0.001).
Effectiveness of Dolutegravir/Lamivudine for the treatments-naive and switching groups

Conclusion
In our long-term follow-up study conducted in South Korea, DTG/3TC worked effectively in viral suppression and CD4 count maintenance, and no significant adverse effects were observed on lipid profiles and body weight gain in both treatment-naïve and switching groups.
Tolerability of Dolutegravir/Lamivudine for the treatments-naive and switching groups

Disclosures
All Authors: No reported disclosures
P-591. Injecting Hope: A Long-Acting Injectable Program to Treat HIV Using Cabotegravir/Rilpivirine at a Ryan-White Funded HIV Clinic
Authors: Vega Victoria , Aragon Kelsea , Azimi Sara , Snyder Jeremy , Iandiorio Michelle , Jakeman Bernadette 
Published: January 2025

Abstract

Background
Cabotegravir/rilpivirine (CAB/RPV) was approved as the first long-acting injectable (LAI) antiretroviral (ART) switch regimen. While clinical trials demonstrate CAB/RPV safety and efficacy, access and clinical workflow challenges have hindered implementation in practice. The objective of this study was to describe use of CAB/RPV in a Ryan-White funded clinic.

Methods
A retrospective chart review was conducted on the first 40 patients, aged &gt; 18 years, referred to the pharmacist CAB/RPV clinic. Referral criteria included HIV-1 RNA &lt; 50 copies/mL and no baseline CAB/RPV resistance.

Results
The majority of patients were male (90%) and white (85%), with a median age of 48 years (range 20-79), BMI of 28 (range 21-48), and use of 6 non-HIV medications (range 0-25). 73% had prior non-adherence to appointments. A DNA archive genotype was obtained for 8 patients due to lack of data. 4 patients had baseline RPV mutations, 2 were identified post-DNA archive genotyping. 14 patients did not start CAB/RPV (6 opted against, 4 had resistance, 2 had insurance denial, 1 had a high copay, 1 moved). The age of those who opted against LAI was not different from those who switched (p=0.2). Pharmacists devoted significant time to patient evaluation and coordination. 26 patients started CAB/RPV; 50% covered by medical benefit, 46% aged &gt; 50 years. Psychological stress/stigma of daily ART was the main reason for switching. 1 patient travelled 228 miles for injections and 1 was homeless. By month 12, 24 patients (92%), including 1 unhoused patient, maintained control on CAB/RPV. No HBV reactivations occurred. 1 patient discontinued due to soreness. 1 patient (BMI &lt; 30, no baseline resistance) had ongoing viremia of &lt; 200 and was switched back to oral ART; post-CAB/RPV DNA archive genotype revealed no mutations.

Conclusion
CBV/RPV offers a switch option for patients, even those with unstable housing or history of missed appointments. Older patients on multiple medications still sought LAI CAB/RPV. Our experience shows that DNA archive genotype testing was valuable in guiding treatment decisions for patients lacking prior data and that proper evaluation and coordination identifies appropriate patients for CAB/RPV, resulting in high continuation rates

Disclosures
All Authors: No reported disclosures
P-592. Rapid initiation of antiretroviral therapy under the Treat-All policy reduces loss to follow-up and virological failure in routine HIV care settings in China: A retrospective cohort study (2016-2022)
Authors: Xia Huan , Ma Ping 
Published: January 2025

Abstract

Background
Following the World Health Organization's guidelines for rapid antiretroviral therapy (ART) initiation [≤ 7 days after human immunodeficiency virus (HIV) diagnosis], China implemented Treat-All in 2016 and has made significant efforts to provide timely ART since 2017. The purpose of this study was to evaluate the effects of rapid ART on loss to follow-up (LTFU) and virological failure compared to those of delayed ART.
Trends in rapid ART initiation (A) and time from HIV diagnosis to treatment initiation (B) from June 2016 to December 2022.

Methods
This research included newly diagnosed HIV-infected adults from Tianjin, China between June 2016 and December 2022. Our primary outcome was LTFU (more than 90 days after the prior drug pick-up or clinical visit) at 12 months following enrollment. The secondary outcome was 12-month virological failure after treatment initiation. Furthermore, Kaplan-Meier estimators were utilized to examine the LTFU time for rapid and delayed ART initiation. Moreover, the correlation between rapid ART initiation and LTFU was evaluated using univariate and multivariable Cox regression, whereas the relationship between rapid ART and 12-month virological failure was investigated via logistic regression.
Kaplan-Meier survival curve of loss to follow-up in ART initiation group.

Results
A total of 896 (19.1%) of 4688 participants received ART ≤ 7 days post-HIV diagnosis. The rate of rapid ART initiation has increased from 7.5% in 2016 to 33.3% by 2022. Rapid ART was less common in persons with baseline CD4 counts of 350 - 499 and ≥ 500 compared to those &lt; 200. Furthermore, it was also less prevalent in individuals who were diagnosed with tuberculosis or had an unknown route of HIV infection, while was more common in people who used Medicare/self-paid medications. The rapid ART group had an LTFU rate of 3.3%, as opposed to 5.0% in the delayed initiation group. Moreover, the rapid ART group had a much reduced virological failure rate (0.6% vs. 1.8%). Rapid ART individuals had a reduced likelihood of LTFU (adjusted hazard ratio: 0.65, 95% CI: 0.44 - 0.96) and virological failure (adjusted odd ratio: 0.35, 95% CI: 0.12 - 0.80).

Conclusion
Under China's Treat-All policy, rapid ART initiation reduced the risk of LTFU and virological failure. The real-world data indicated that rapid ART initiation is practicable and beneficial for Chinese people with HIV, providing evidence and guide for its widespread implementation and scaling up.

Disclosures
All Authors: No reported disclosures
P-594. Temperature Stability of BPL-1357, a BPL-Inactivated, Whole-Virus, Universal Influenza Vaccine
Authors: Banerjee Camellia , Giurgea Luca Tudor , Cervantes-Medina Adriana , Taubenberger Jeffery , Memoli Matthew J 
Published: January 2025

Abstract

Background
Influenza A viruses (IAV) present a constant public health threat from seasonal epidemics to potential pandemics. Currently approved vaccines perform poorly against mismatched seasonal influenza strains and are unlikely to provide any protection against a pandemic potential influenza such as avian influenza. We have developed a vaccine composed of four β-propiolactone-inactivated (BPL-inactivated) low-pathogenicity avian IAV subtypes (H1N9, H3N8, H5N1 and H7N3) which demonstrated protection against lethal challenge with a wide variety of influenza subtypes in mice and ferrets. Human trials are ongoing but even with a promising vaccine, thermal stability can still be an issue that could limit use in resource-poor settings.

Methods
The four components of BPL-inactivated vaccine were stored individually at four different conditions, -80°C, -20°C, 4°C, and room temperature. Hemagglutination (HA), neuraminidase activity (NA), and protein assays were done for each temperature condition after 7 and 28 days of storage.

Results
Baseline protein concentrations were similar across vaccine components. After 28 day incubation, protein concentrations remained stable at room temperature and at 4°C for H1N9 and H7N3, but decreased for H3N8 and H5N1, more at room temperature to 52.1% and 56.1% of Day 0 concentration respectively. At 4°C there was less loss of protein for those components. Activity of NA and HA varied at baseline; for example H3 and H5 had much higher activity (1280) than H1 (160) and H7 (320) and NA activity was highest for N1 (482.22 mU/ml) and lowest for N9 (33.65 mU/ml). HA and NA activity was stable for 28 days at room temperature and 4°C. At -20°C, HA activity showed marked declines within 7 days. Overall, our data shows stability of protein and HA and NA activity at 4°C for up to 28 days, and some short-term stability at room temperature.

Conclusion
Developing a universal flu vaccine would contribute greatly to preventing future pandemics. However, for global use, this vaccine would need to be stable and distributable. Here we show that we may potentially have a vaccine that is both efficacious and shelf stable at 4°C. Further evaluation of immunogenicity at different temperature conditions should be performed, especially to resolve discordance between protein and activity assays.

Disclosures
All Authors: No reported disclosures
P-599. 6-Valent, OspA-Based VLA15 Lyme Disease Vaccine Candidate Against Lyme Borreliosis in a Healthy Pediatric and Adult Study Population: A Phase 2 Study Update
Authors: Messier Marc D , Wagner Laura , Hochreiter Romana , Lamberth Erik , Larcher-Senn Julian , Simon Raphael , groark James , Stark James H 
Published: January 2025

Abstract

Background
Lyme borreliosis (LB) is the most common tick-borne disease in the US, with approximately 476,000 cases diagnosed and treated annually and nearly 90 million individuals living in high incidence jurisdictions. Vector-focused prevention measures have varying levels of effectiveness due to low utilization, poor adherence, or high cost. A safe and efficacious vaccine to prevent LB is warranted. We provide an update on the Pfizer-Valneva VLA15 vaccine clinical development program, specifically the safety and immunogenicity booster data of the phase 2 trial (NCT04801420).

Methods
A randomized, observer-blinded, multi-centre Phase 2 study investigated the safety and immunogenicity of VLA15 in adult and pediatric study populations. A total of 625 participants aged 5-65 years were enrolled in three age groups (5-11 years, 12-17 years, and 18-65 years) and randomized 1:1:1 to receive VLA15 180 mcg with alum in a three-dose (Month 0-2-6) or a two-dose schedule (Month 0-6), or three injections of placebo (Month 0-2-6) followed by booster doses at Month 18 and Month 30. Safety and immunogenicity data up to one month after completion of the primary vaccination series and yearly booster doses are presented.

Results
Up to Month 19, VLA15 was safe and well tolerated in all age groups after all doses. Most adverse reactions were mild or moderate in severity. No related SAEs or other safety concerns were reported. The VLA15 booster dose induced a robust, anamnestic immune response against all six OspA vaccine serotypes in all age groups. Immune responses in children were higher than in adults across both schedules.

Conclusion
The Month 18 VLA15-221 booster dose was safe and immunogenic in both adults and children. The Month 30 booster data is under analysis. The ongoing blinded Phase 3 trials in Europe and North America will provide additional data which may support use of this vaccine as the primary preventative measure to protect against LB.

Disclosures
Marc D. Messier, PhD, SOBI: Advisor/Consultant|Valneva: employee|Valneva: Ownership Interest Laura Wagner, M.Sc., Valneva: employee Romana Hochreiter, PhD, Valneva Austria GmbH: WO2021/207615 A1|Valneva Austria GmbH: Employee, owner of stock options Erik Lamberth, MD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Julian Larcher-Senn, PhD, Valneva: Advisor/Consultant Raphael Simon, PhD, Pfizer: Stocks/Bonds (Private Company) James groark, MD, Pfizer: Stocks/Bonds (Public Company) James H. Stark, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company)
P-610. HPV vaccine knowledge, attitudes and practices among healthcare providers before introduction to the national schedule, Almaty, Kazakhstan - 2023
Authors: Ablimitova Feruza , Nabirova Dilyara , Horth Roberta , Kirpicheva Ulyana , Gazezova Saya , Smagul Manar 
Published: January 2025

Abstract

Background
Healthcare providers play a vital role in the success of new vaccine uptake. In 2024, Kazakhstan will introduce the human papillomavirus (HPV) vaccine into the immunization schedule after a 2013 pilot was unsuccessful due largely to widespread misinformation. We aimed to establish baseline knowledge, attitudes, and practices (KAP) related to HPV vaccination among providers to prepare for vaccine rollout.

Methods
We conducted a cross-sectional study in April-May 2023 of healthcare providers responsible for vaccinations in all 34 polyclinics that conduct vaccinations in Almaty. Providers completed anonymous questionnaires in group sessions. KAP domain scores &gt;70% were considered adequate. We used multinomial logistic regression to assess factors associated with intent to recommend HPV vaccines; we presented odds ratios and 95% confidence intervals (95%CI).

Results
Of 832 participants, 68% were nurses and 41% had at least one &lt; 18-year-old child (Table 1). One-third (33%) had adequate knowledge about HPV; specifically, 71% correctly believed HPV is not airborne, and 22% knew HPV infection is not currently curable. One-fifth (20%) had adequate attitudes towards HPV; and 39% knew that HPV vaccines don’t cause infertility. On questions related to routine childhood immunizations, 61% could not correctly dispel common myths. One-quarter (28%) would recommend the HPV vaccine to patients and to their own or friends’ children. The odds of recommending the HPV vaccine were lower for nurses compared to physicians (OR=0.5, 95%CI=0.3, 0.9), for providers with inadequate HPV knowledge compared to adequate (0.6, 95%CI=0.4, 1.0), and for those who believed common myths compared to those who didn’t (0.6, 95%CI=0.4, 1.0) (Table 2). The odds of recommending the vaccine were higher for providers with adequate attitudes towards HPV vaccine myths compared to those without (1.4, 95%CI=0.8, 2.5) and for those with adequate knowledge of childhood vaccine safety compared to those without (2.3, 95%CI= 1.3, 4.0).

Conclusion
We found suboptimal KAP towards HPV vaccines. Results demonstrate the need to prioritize the rollout of a vaccine education, communication, and advocacy strategy to healthcare providers before the national HPV vaccine rollout.

Disclosures
Ulyana Kirpicheva, M.Sc. in FIeld Epidemiology, Abbott Laboratories: Grant/Research Support