Adverse drug reactions attributed to generic substitution of antiretroviral medications among HIV treatment and pre-exposure prophylaxis clients in British Columbia, Canada.

BACKGROUND: In British Columbia, antiretrovirals (ARVs) for HIV treatment (HIV-Tx) and pre-exposure prophylaxis (PrEP) are free-of-charge through publicly-funded Drug Treatment Programs (DTPs). When available, less costly generics are substituted for brand-name ARVs. We describe the incidence and type of product substitution issue (PSI) adverse drug reactions (ADRs) attributed to generic ARVs. METHODS: Cohorts included DTP clients ≥19 years who received generic ARVs for HIV-Tx (abacavir-lamivudine, emtricitabine-tenofovir DF, efavirenz-emtricitabine-tenofovir DF, atazanavir or darunavir between 01 Jun 2017 and 30 Jun 2022) or PrEP (emtricitabine-tenofovir DF, 01 Apr 2018 to 30 Jun 2022). Demographic, ARV and ADR data were extracted from DTP databases and summarized by descriptive statistics. PSI incidence was calculated for each product during the year following brand-to-generic and generic-to-generic transitions (first-year-post-rollout), and compared between generic versions using generalized estimating equations. For context, incidence of any ARV product-related ADR was calculated in the same 1-year periods. RESULTS: During first-year-post-rollout periods, 5339 HIV-Tx (83% male, median age 52 years) and 8095 PrEP (99% male, median 33 years) clients received generic ARVs, and reported 78 and 23 generic PSIs, respectively. PSI incidence was <1% for most generic ARVs, with mild-moderate symptoms including gastrointestinal upset, headache, dizziness, fatigue/malaise and skin rash. In HIV-Tx clients, the efavirenz-containing product had higher PSI incidence than other ARVs (2.2%, p = .004), due to more neuropsychiatric adverse reactions. Any ADR incidence was stable across measurement periods, and generic PSIs represented less than one third of all product-related ADRs. CONCLUSIONS: Generic substitution of antiretrovirals for HIV-Tx and PrEP was well tolerated, with ≤2% incidence of mild-moderate PSI ADRs.

Examining the secondary impacts of the COVID-19 pandemic on syndemic production and PrEP use among gay, bisexual and other men who have sex with men (GBM) in Vancouver, Canada.

BACKGROUND: The secondary impacts of the COVID-19 pandemic may disproportionately affect gay, bisexual, and other men who have sex with men (GBM), particularly related to HIV prevention and treatment outcomes. We applied syndemic theory to examine PrEP disruptions during the during the height of the COVID-19 pandemic in Vancouver, Canada. METHODS: Sexually-active GBM, aged 16 + years, were enrolled through respondent-driven sampling (RDS) from February 2017 to August 2019. Participants completed a Computer-Assisted Self-Interview every six months and data were linked to the BC PrEP Program (program responsible for publicly funded PrEP in the province) to directly measure PrEP disruptions. The analysis period for this study was from March 2018-April 2021. We used univariable generalized linear mixed models to examine (1) six-month trends for syndemic conditions: the prevalence of moderate/severe depressive or anxiety symptoms, polysubstance use, harmful alcohol consumption, intimate partner violence, and (2) six-month trends for PrEP interruptions among HIV-negative/unknown GBM. We also applied 3-level mixed-effects logistic regression with RDS clustering to examine whether syndemic factors were associated with PrEP interruptions. RESULTS: Our study included 766 participants, with 593 participants who had at least one follow-up visit. The proportion of respondents with abnormal depressive symptoms increased over the study period (OR = 1.35; 95%CI = 1.17, 1.56), but we found decreased prevalence for polysubstance use (OR = 0.89; 95%CI = 0.82, 0.97) and binge drinking (OR = 0.74; 95%CI = 0.67, 0.81). We also found an increase in PrEP interruptions (OR = 2.33; 95%CI = 1.85, 2.94). GBM with moderate/severe depressive symptoms had higher odds (aOR = 4.80; 95%CI = 1.43, 16.16) of PrEP interruptions, while GBM with experiences of IPV had lower odds (aOR = 0.38; 95%CI = 0.15, 0.95) of PrEP interruptions. GBM who met clinical eligibility for PrEP had lower odds of experiencing PrEP interruptions (aOR = 0.25; 95%CI = 0.11, 0.60). CONCLUSION: There were increasing PrEP interruptions since March 2020. However, those most at risk for HIV were less likely to have interruptions. Additional mental health services and targeted follow-up for PrEP continuation may help to mitigate the impacts of the COVID-19 pandemic on GBM.

Identification of people with low prevalence diseases in administrative healthcare records: A case study of HIV in British Columbia, Canada.

INTRODUCTION: Case-finding algorithms can be applied to administrative healthcare records to identify people with diseases, including people with HIV (PWH). When supplementing an existing registry of a low prevalence disease, near-perfect specificity helps minimize impacts of adding in algorithm-identified false positive cases. We evaluated the performance of algorithms applied to healthcare records to supplement an HIV registry in British Columbia (BC), Canada. METHODS: We applied algorithms based on HIV-related diagnostic codes to healthcare practitioner and hospitalization records. We evaluated 28 algorithms in a validation sub-sample of 7,124 persons with positive HIV tests (2,817 with a prior negative test) from the STOP HIV/AIDS data linkage-a linkage of healthcare, clinical, and HIV test records for PWH in BC, resembling a disease registry (1996-2020). Algorithms were primarily assessed based on their specificity-derived from this validation sub-sample-and their impact on the estimate of the total number of PWH in BC as of 2020. RESULTS: In the validation sub-sample, median age at positive HIV test was 37 years (Q1: 30, Q3: 46), 80.1% were men, and 48.9% resided in the Vancouver Coastal Health Authority. For all algorithms, specificity exceeded 97% and sensitivity ranged from 81% to 95%. To supplement the HIV registry, we selected an algorithm with 99.89% (95% CI: 99.76% - 100.00%) specificity and 82.21% (95% CI: 81.26% - 83.16%) sensitivity, requiring five HIV-related healthcare practitioner encounters or two HIV-related hospitalizations within a 12-month window, or one hospitalization with HIV as the most responsible diagnosis. Upon adding PWH identified by this highly-specific algorithm to the registry, 8,774 PWH were present in BC as of March 2020, of whom 333 (3.8%) were algorithm-identified. DISCUSSION: In the context of an existing low prevalence disease registry, the results of our validation study demonstrate the value of highly-specific case-finding algorithms applied to administrative healthcare records to enhance our ability to estimate the number of PWH living in BC.

Process description of developing HIV prevention monitoring indicators for a province-wide pre-exposure prophylaxis (PrEP) program in British Columbia, Canada.

In 2018, the pre-exposure prophylaxis (PrEP) program was initiated in British Columbia (BC), Canada, providing PrEP at no cost to qualifying residents. This observational study discussed the steps to develop key evidence-based monitoring indicators and their calculation using real-time data. The indicators were conceptualized, developed, assessed and approved by the Technical Monitoring Committee of representatives from five health authority regions in BC, the BC Ministry of Health, the BC Centre for Disease Control, and the BC Centre for Excellence in HIV/AIDS. Indicator development followed the steps adopted from the United States Centers for Disease Control and Prevention framework for program evaluation in public health. The assessment involved eight selection criteria: data quality, indicator validity, existing scientific evidence, indicator informativeness, indicator computing feasibility, clients' confidentiality maintenance capacity, indicator accuracy, and administrative considerations. Clients' data from the provincial-wide PrEP program (January 2018-December 2020) shows the indicators' calculation. The finalized 14 indicators included gender, age, health authority, new clients enrolled by provider type and by the health authority, new clients dispensed PrEP, clients per provider, key qualifying HIV risk factor(s), client status, PrEP usage type, PrEP quantity dispensed, syphilis and HIV testing and incident cases, and adverse drug reaction events. Cumulative clients' data (n = 6966; 99% cis-gender males) identified an increased new client enrollment and an unexpected drop during the COVID-19 pandemic. About 80% dispensed PrEP from the Vancouver Coastal health authority. The HIV incidence risk index for men who have sex with men score ≥10 was the most common qualifying risk factor. The framework we developed integrating indicators was applied to monitor our PrEP program, which could help reduce the public health impact of HIV.

People With Human Immunodeficiency Virus Receiving Suppressive Antiretroviral Therapy Show Typical Antibody Durability After Dual Coronavirus Disease 2019 Vaccination and Strong Third Dose Responses.

BACKGROUND: Longer-term humoral responses to 2-dose coronavirus disease 2019 (COVID-19) vaccines remain incompletely characterized in people living with human immunodeficiency virus (HIV) (PLWH), as do initial responses to a third dose. METHODS: We measured antibodies against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein receptor-binding domain, angiotensin-converting enzyme 2 (ACE2) displacement, and viral neutralization against wild-type and Omicron strains up to 6 months after 2-dose vaccination, and 1 month after the third dose, in 99 PLWH receiving suppressive antiretroviral therapy and 152 controls. RESULTS: Although humoral responses naturally decline after 2-dose vaccination, we found no evidence of lower antibody concentrations or faster rates of antibody decline in PLWH compared with controls after accounting for sociodemographic, health, and vaccine-related factors. We also found no evidence of poorer viral neutralization in PLWH after 2 doses, nor evidence that a low nadir CD4+ T-cell count compromised responses. Post-third-dose humoral responses substantially exceeded post-second-dose levels, though Omicron-specific responses were consistently weaker than responses against wild-type virus. Nevertheless, post-third-dose responses in PLWH were comparable to or higher than controls. An mRNA-1273 third dose was the strongest consistent correlate of higher post-third-dose responses. CONCLUSION: PLWH receiving suppressive antiretroviral therapy mount strong antibody responses after 2- and 3-dose COVID-19 vaccination. Results underscore the immune benefits of third doses in light of Omicron.

Antibody response durability following three-dose coronavirus disease 2019 vaccination in people with HIV receiving suppressive antiretroviral therapy.

BACKGROUND: Limited data exist regarding longer term antibody responses following three-dose coronavirus disease 2019 (COVID-19) vaccination, and the impact of a first SARS-CoV-2 infection during this time, in people with HIV (PWH) receiving suppressive antiretroviral therapy (ART). We quantified wild-type-specific, Omicron BA.1-specific and Omicron BA.5-specific responses up to 6 months post-third dose in 64 PWH and 117 controls who remained COVID-19-naive or experienced their first SARS-CoV-2 infection during this time. DESIGN: Longitudinal observational cohort. METHODS: We quantified wild-type-specific and Omicron-specific anti-Spike receptor-binding domain IgG concentrations, ACE2 displacement activities and live virus neutralization at 1, 3 and 6 months post-third vaccine dose. RESULTS: Third doses boosted all antibody measures above two-dose levels, but BA.1-specific responses remained significantly lower than wild-type-specific ones, with BA.5-specific responses lower still. Serum IgG concentrations declined at similar rates in COVID-19-naive PWH and controls post-third dose (median wild-type-specific and BA.1-specific half-lives were between 66 and 74 days for both groups). Antibody function also declined significantly yet comparably between groups: 6 months post-third dose, BA.1-specific neutralization was undetectable in more than 80% of COVID-19 naive PWH and more than 90% of controls. Breakthrough SARS-CoV-2 infection boosted antibody concentrations and function significantly above vaccine-induced levels in both PWH and controls, though BA.5-specific neutralization remained significantly poorer than BA.1 even post-breakthrough. CONCLUSION: Following three-dose COVID-19 vaccination, antibody response durability in PWH receiving ART is comparable with controls. PWH also mounted strong responses to breakthrough infection. Due to temporal response declines, however, COVID-19-naive individuals, regardless of HIV status, would benefit from a fourth dose within 6 months of their third.

Impact of SARS-CoV-2 lockdown on expansion of HIV transmission clusters among key populations: A retrospective phylogenetic analysis.

Background: Public health measures designed to reduce SARS-CoV-2 transmission led to reduced access to care and prevention services for people living with or at risk of acquiring HIV, particularly during the initial introduction of extensive restrictions. This reduction in access may have contributed to increases in HIV transmission not outweighed by decreases in transmission occurring as a result of reduced contact rates promoted by the same public health measures. Methods: We synthesize available province-wide HIV data in British Columbia, Canada, together with public mobility data to phylogenetically investigate the early impacts of SARS-CoV-2 on HIV transmission. Cluster growth, coalescent branching events and lineage-level diversification rates were assessed in "pre-lockdown" (January 22-March 21, 2020), "lockdown" (March 22-May 20, 2020) and "post-lockdown" (May 21-July 19, 2020) to facilitate comparison of transmission trends across key populations. Findings: Results reveal increased HIV transmission in a limited number of clusters in association with reduced access to health services during the initial introduction of SARS-CoV-2-related restrictions. In particular, clusters associated with people who inject drugs (PWID) show rapid growth, extensive branching events in phylogenetic trees during and following the lockdown period, and elevated median change in individuals' viral diversification rates during lockdown compared to clusters associated with men who have sex with men (MSM), consistent with increased transmission rates between PWID. Interpretation: Increased vigilance and innovative targeted solutions are critical to offset potential negative impacts of SARS-CoV-2 or future pandemic-related restrictions on HIV epidemic dynamics. Funding: Funding sources include Genome Canada and Genome BC, the Public Health Agency of Canada, the BC Centre for Excellence in HIV/AIDS, and the Canadian Institutes of Health Research Coronavirus Rapid Response Programme. Student funding includes a NSERC CREATE scholarship and a Canadian Institutes of Health Research graduate fellowship.

Risk Factors, Screening, Diagnosis, and Treatment of Osteoporosis in HIV-Infected Adults in an HIV Primary Care Clinic.

Background: The population of people living with HIV is aging, and with aging come emergent comorbidities, including osteoporosis, for which screening and treatment are becoming increasingly important. Osteoporosis prevalence among those living with HIV is 3 times greater than among HIV-uninfected controls. Objective: To assess and describe osteoporosis risk factors, screening, diagnosis, and treatment for people 50 years of age or older living with HIV and receiving care at a multidisciplinary HIV primary care clinic. Methods: A retrospective chart review of people 50 years of age or older living with HIV was conducted at the John Ruedy Clinic in Vancouver, British Columbia, between June 1, 2016, and June 1, 2019. Patients who had had fewer than 2 yearly follow-up appointments were excluded. Results: A total of 146 patients were included in the analysis; most were male (n = 134, 92%), and the median age was 55 years. Patients had a median of 3 osteoporosis risk factors (in addition to age and HIV infection), and 145 patients had at least 1 risk factor. All screening for osteoporosis was conducted by dual-energy X-ray absorptiometry (DXA). Thirty-nine (27%) of the patients were screened with DXA, 92 (63%) were not screened, and 15 (10%) already had a diagnosis of osteoporosis. The DXA screening identified osteoporosis in an additional 10 patients and osteopenia in 22 patients. Treatments for patients with osteoporosis included bisphosphonates (n = 15, 60%) and vitamin D or calcium (or both), without any other medications (n = 4, 16%). In the overall study population, 32 (22%) of the patients were taking calcium and 46 (32%) were taking vitamin D. Conclusions: Many patients aged 50 years or older and receiving HIV care at the John Ruedy Clinic had or were at risk for osteoporosis. An opportunity exists to increase screening and treatment of these individuals. A multidisciplinary team may be crucial in achieving this goal.

Contexte: La population des personnes vivant avec le VIH vieillit et, avec le vieillissement, des comorbidités émergent, dont l'ostéoporose, pour laquelle le dépistage et le traitement sont de plus en plus importants. La prévalence de l'ostéoporose chez les personnes vivant avec le VIH est 3 fois plus élevée que chez les témoins non infectés. Objectif: Évaluer et décrire les facteurs de risque, le dépistage, le diagnostic et le traitement de l'ostéoporose chez les personnes d'au moins 50 ans vivant avec le VIH et qui reçoivent des soins dans une clinique pluridisciplinaire de soins primaires pour le VIH. Méthodes: Un examen rétrospectif des dossiers des personnes d'au moins 50 ans vivant avec le VIH a été effectué à la clinique John Ruedy à Vancouver (Colombie-Britannique) entre le 1er juin 2016 et le 1er juin 2019. Les patients qui avaient eu moins de 2 rendez-vous de suivi annuels ont été exclus de l'étude. Résultats: Au total, 146 patients ont été inclus dans l'analyse; la plupart étaient des hommes (n = 134, 92 %) et l'âge médian était de 55 ans. Les patients avaient une médiane de 3 facteurs de risque d'ostéoporose (en plus de l'âge et de l'infection par le VIH), et 145 patients avaient au moins 1 facteur de risque. Tous les dépistages de l'ostéoporose ont été réalisés par absorption biphotonique à rayons X (DXA). Trente-neuf patients (27 %) ont été dépistés par DXA, 92 (63 %) ne l'ont pas été et 15 (10 %) avaient déjà un diagnostic d'ostéoporose. Le dépistage par DXA a permis d'identifier l'ostéoporose chez 10 patients supplémentaires et l'ostéopénie chez 22 patients. Le traitement des patients atteints d'ostéoporose comprenait des bisphosphonates (n = 15, 60 %) et de la vitamine D ou du calcium (ou les deux) sans autre médicament (n = 4, 16 %). Dans la population générale de l'étude, 32 patients (22 %) prenaient du calcium et 46 (32 %) prenaient de la vitamine D. Conclusions: De nombreux patients d'au moins 50 ans recevant des soins pour le VIH à la clinique John Ruedy présentaient un risque d'ostéoporose ou l'avaient déjà développée. Il est possible d'accroître leur dépistage et leur traitement, et une équipe multidisciplinaire peut être cruciale pour atteindre cet objectif.

Evolving patterns of antiretroviral drug interactions in people with HIV in British Columbia, Canada.

OBJECTIVES: To characterize the annual prevalence of antiretroviral/nonantiretroviral drug interactions in relation to antiretroviral therapy (ART)-prescribing patterns, and to describe drug interaction-related ART changes. DESIGN/METHODS: This cohort study included ART-treated adults in British Columbia, Canada between 01 January 2010 and 31 December 2016. Medication dispensing records were abstracted from a population-based, linked administrative-health dataset and used to identify antiretroviral-comedication drug interactions ('caution'/'avoid' drug interactions in HIV-focused drug interaction checkers). We identified temporal trends in annual drug interaction prevalence and quantified the association between taking higher drug interaction-risk ART and receiving nonrecommended antiretroviral-comedication combinations using Poisson regression models, modified for binary outcomes and correlated data. Clinician-reported, drug interaction-related ART changes and associated adverse events were abstracted from an HIV drug treatment registry and summarized descriptively. RESULTS: Among 8571 ART-treated adults who received nonantiretroviral comedications, prevalence of having any drug interaction or receiving nonrecommended drug combination(s) significantly declined from 85 to 71% and 5.6 to 3.2%, respectively, between 2010 and 2016 ( P  < 0.001). This paralleled a shift from higher drug interaction-risk ART (e.g. ritonavir/cobicistat-boosted protease inhibitors) to lower drug interaction-risk ART (e.g. unboosted integrase inhibitors). Risk of receiving a nonrecommended antiretroviral-comedication combination was greater for persons taking higher vs. lower drug interaction-risk ART [adjusted risk ratio (aRR) 3.12, 95% confidence interval (CI) 2.24-4.35]. Boosted antiretroviral-inhaled corticosteroid drug interactions accounted for the most commonly dispensed, nonrecommended drug combinations, and the most commonly reported drug interaction-related adverse events (adrenal insufficiency). CONCLUSION: The prevalence of antiretroviral-comedication drug interactions is declining as ART shifts towards antiretrovirals with lower drug interaction potential but nonrecommended drug combinations remain a concern. Healthcare providers should screen for drug interactions whenever drugs are prescribed or dispensed.

People with HIV receiving suppressive antiretroviral therapy show typical antibody durability after dual COVID-19 vaccination, and strong third dose responses.

Background: Longer-term humoral responses to two-dose COVID-19 vaccines remain incompletely characterized in people living with HIV (PLWH), as do initial responses to a third dose. Methods: We measured antibodies against the SARS-CoV-2 spike protein receptor-binding domain, ACE2 displacement and viral neutralization against wild-type and Omicron strains up to six months following two-dose vaccination, and one month following the third dose, in 99 PLWH receiving suppressive antiretroviral therapy, and 152 controls. Results: Though humoral responses naturally decline following two-dose vaccination, we found no evidence of lower antibody concentrations nor faster rates of antibody decline in PLWH compared to controls after accounting for sociodemographic, health and vaccine-related factors. We also found no evidence of poorer viral neutralization in PLWH after two doses, nor evidence that a low nadir CD4+ T-cell count compromised responses. Post-third-dose humoral responses substantially exceeded post-second-dose levels, though anti-Omicron responses were consistently weaker than against wild-type.Nevertheless, post-third-dose responses in PLWH were comparable to or higher than controls. An mRNA-1273 third dose was the strongest consistent correlate of higher post-third-dose responses. Conclusion: PLWH receiving suppressive antiretroviral therapy mount strong antibody responses after two- and three-dose COVID-19 vaccination. Results underscore the immune benefits of third doses in light of Omicron.

Prevalence and incidence of hepatitis C infection amongst men who have sex with men in a population-based pre-exposure prophylaxis program in British Columbia, Canada.

BACKGROUND: Men who have sex with men (MSM) are at risk for sexually-transmitted hepatitis C (HCV). Evidence for HCV infection in the context of pre-exposure prophylaxis (PrEP) use in North America is limited. We sought to characterize baseline HCV prevalence and incidence in MSM receiving PrEP in British Columbia (BC), Canada. METHODS: We followed individuals in the BC PrEP program from January 2018 to August 2019. We evaluated baseline prevalence and incident seroconversions (newly positive HCV antibody). A multivariable logistic regression model was performed in MSM for factors associated with HCV prevalence at enrollment, including reported prior sexually transmitted infection (STI), HIV Incidence Risk Index for MSM score, PrEP use because of a partner living with HIV, and location of residence. RESULTS: The median age of the cohort was 33 years, 98.3% male, with 3058 person years (PY) of follow-up. Baseline HCV prevalence was 0.82% (31/3907 MSM enrollees) and HCV incidence (n = 3) was 0.15 per 100 PY (95% confidence interval [CI] 0.03-0.45). In multivariable analysis, initiating PrEP because of a partner living with HIV (adjusted odds ratio [aOR] 5.02; 95% CI 1.87-13.47) and prior STI (aOR 2.34; 95% CI 1.04-5.24) were associated with positive HCV status. CONCLUSIONS: Baseline HCV prevalence and incidence was low amongst MSM in a population-based PrEP program in BC, Canada. HCV was associated with bridging from populations living with HIV and evidence of a reported prior STI as a PrEP indicator condition amongst MSM. PrEP initiation may be an opportunity for linkage to HCV screening and treatment.

Humoral immune responses to COVID-19 vaccination in people living with HIV receiving suppressive antiretroviral therapy.

Humoral responses to COVID-19 vaccines in people living with HIV (PLWH) remain incompletely characterized. We measured circulating antibodies against the SARS-CoV-2 spike protein receptor-binding domain (RBD), ACE2 displacement and viral neutralization activities one month following the first and second COVID-19 vaccine doses, and again 3 months following the second dose, in 100 adult PLWH and 152 controls. All PLWH were receiving suppressive antiretroviral therapy, with median CD4+ T-cell counts of 710 (IQR 525-935) cells/mm3, though nadir CD4+ T-cell counts ranged as low as <10 cells/mm3. After adjustment for sociodemographic, health and vaccine-related variables, HIV infection was associated with lower anti-RBD antibody concentrations and ACE2 displacement activity after one vaccine dose. Following two doses however, HIV was not significantly associated with the magnitude of any humoral response after multivariable adjustment. Rather, older age, a higher burden of chronic health conditions, and dual ChAdOx1 vaccination were associated with lower responses after two vaccine doses. No significant correlation was observed between recent or nadir CD4+ T-cell counts and responses to two vaccine doses in PLWH. These results indicate that PLWH with well-controlled viral loads and CD4+ T-cell counts in a healthy range generally mount strong initial humoral responses to dual COVID-19 vaccination. Factors including age, co-morbidities, vaccine brand, response durability and the rise of new SARS-CoV-2 variants will influence when PLWH will benefit from additional doses. Further studies of PLWH who are not receiving antiretroviral treatment or who have low CD4+ T-cell counts are needed, as are longer-term assessments of response durability.

Chronic Hepatitis B Infection Among Preexposure Prophylaxis Users Enrolled in a Population-Based Program in British Columbia, Canada.

Initiation of human immunodeficiency virus preexposure prophylaxis (PrEP) medications will also treat hepatitis B infection (HBV). The prevalence of chronic HBV was 0.86% (n=41/4760) among enrollees in a provincial PrEP program in British Columbia, Canada. Overall, 46.3% lacked follow-up HBV DNA monitoring, underscoring the need for HBV-related education for PrEP prescribers.

Humoral immune responses to COVID-19 vaccination in people living with HIV receiving suppressive antiretroviral therapy.

Humoral responses to COVID-19 vaccines in people living with HIV (PLWH) remain incompletely understood. We measured circulating antibodies against the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein, ACE2 displacement and live viral neutralization activities one month following the first and second COVID-19 vaccine doses in 100 adult PLWH and 152 controls. All PLWH were receiving suppressive antiretroviral therapy, with median CD4+ T-cell counts of 710 (IQR 525-935) cells/mm 3 . Nadir CD4+ T-cell counts ranged as low as <10 (median 280; IQR 120-490) cells/mm 3 . After adjustment for sociodemographic, health and vaccine-related variables, HIV infection was significantly associated with 0.2 log 10 lower anti-RBD antibody concentrations (p=0.03) and ∻11% lower ACE2 displacement activity (p=0.02), but not lower viral neutralization (p=0.1) after one vaccine dose. Following two doses however, HIV was no longer significantly associated with the magnitude of any response measured. Rather, older age, a higher burden of chronic health conditions, and having received two ChAdOx1 doses (versus a heterologous or dual mRNA vaccine regimen) were independently associated with lower responses. After two vaccine doses, no significant correlation was observed between the most recent or nadir CD4+ T-cell counts and vaccine responses in PLWH. These results suggest that PLWH with well-controlled viral loads on antiretroviral therapy and CD4+ T-cell counts in a healthy range will generally not require a third COVID-19 vaccine dose as part of their initial immunization series, though other factors such as older age, co-morbidities, vaccine regimen type, and durability of vaccine responses will influence when this group may benefit from additional doses. Further studies of PLWH who are not receiving antiretroviral treatment and/or who have low CD4+ T-cell counts are needed.

Untimed Efavirenz Drug Levels After Switching From Brand to Generic Formulations: A Short Communication.

BACKGROUND: In British Columbia, antiretrovirals are distributed at no cost to patients via a publicly funded program, using generic formulations if available. A generic efavirenz-emtricitabine-tenofovir DF (EFV-FTC-TDF) combination pill became available in April 2018. The authors compared EFV untimed drug levels in subjects switching from brand to generic EFV-FTC-TDF. METHODS: Archived plasma HIV viral load samples were identified for consenting participants who switched from brand to generic EFV-FTC-TDF; 3 preswitch and 2-3 postswitch samples, collected ≥1 month apart were assessed for each subject. "Untimed" EFV concentrations with unknown dosing and collection time were assessed using a validated liquid chromatography-tandem mass spectrometry method. Participants' mean, minimum, and maximum EFV levels were compared using the Wilcoxon signed rank test. Participants with EFV levels in the range associated with lower risks of virologic failure and central nervous system toxicity (1000-4000 ng/mL), preswitch and postswitch, were enumerated. RESULTS: EFV levels were assessed in 297 preswitch and 249 postswitch samples from 99 participants, having exposure to brand and generic EFV for a median of 103 (Q1-Q3: 87-116) and 10.3 (Q1-Q3: 8.9-11.7) months, respectively. The final brand sample was collected at a median of 98 days preswitch; the first generic sample was collected at a median of 133 days postswitch. No significant differences were observed in participant mean EFV levels before (median 1968 ng/mL; Q1-Q3: 1534-2878 ng/mL) and after (median 1987 ng/mL; Q1-Q3: 1521-2834 ng/mL) switch (P = 0.85). Eighty participants had mean EFV levels within the 1000-4000 ng/mL range on the brand drug, of which 74 remained within this range postswitch. CONCLUSIONS: There were no statistically significant differences between untimed EFV levels in patients switching from the brand to generic EFV combination pill. Given the long elimination half-life of EFV, untimed drug levels may be a convenient way to estimate product bioequivalence.

Adverse drug reactions to integrase strand transfer inhibitors.

OBJECTIVES: To describe and compare integrase strand transfer inhibitor (INSTI) adverse drug reactions (ADRs) for raltegravir, elvitegravir-cobicistat, and dolutegravir. DESIGN: Population-based, retrospective cohort. METHODS: Antiretroviral-experienced and naive persons at least 19 years old were included if they received their first prescription for raltegravir, elvitegravir-cobicistat, or dolutegravir in British Columbia, Canada, in 2012-2014, and were followed for 2 years until 31 December 2016. The primary outcome was an ADR resulting in INSTI discontinuation. ADR rates and 95% confidence intervals (95% CIs) were calculated by Poisson method. Cox proportional-hazards regression estimated the hazard ratio for ADR-related INSTI discontinuation, adjusted for confounders. ADR symptoms were compared across INSTIs. RESULTS: There were 1344 persons contributing 1464 person-INSTI exposures. The cohort was predominantly male (79%) and antiretroviral therapy-experienced (85%). ADR events and unadjusted ADR rates (95% CI) per 100 person-years were raltegravir 24 of 551 (4.4%), 2.91 (1.95, 4.35); elvitegravir-cobicistat 38 of 394 (9.6%), 5.94 (4.32, 8.16); and dolutegravir 27 of 519 (5.2%), 2.96 (2.03, 4.31). The ADR rate for elvitegravir-cobicistat was double that of dolutegravir (adjusted hazard ratio 2.24, 95% CI 1.13, 4.44), but not significantly different for either dolutegravir or elvitegravir versus raltegravir. Elvitegravir-cobicistat-treated persons had a significantly higher proportion of gastrointestinal and general (fatigue, malaise) ADRs. Neuropsychiatric ADRs were more frequent with dolutegravir, but not significantly different between INSTIs. Among those switching between INSTIs, there was no apparent relationship between experiencing an ADR to one INSTI and subsequent intolerance to another. CONCLUSIONS: This study affirms INSTIs are well tolerated during routine clinical use. Consideration of differences in side effect profiles can inform antiretroviral therapy individualization.

Emergent drug resistance with integrase strand transfer inhibitor-based regimens.

OBJECTIVES: To estimate the incidence of and risk factors for emergent resistance to integrase strand transfer inhibitor (INSTI) and nucleoside(-tide) reverse transcriptase inhibitors (NRTI) in HIV-1-infected adults receiving an INSTI and two NRTIs. DESIGN: Retrospective cohort study. METHODS: Persons aged at least 19 years were included if they received their first prescription for raltegravir, elvitegravir or dolutegravir in British Columbia, Canada in 2012-2014 and were followed to 31 December 2015. Emergent resistance was defined as new mutations conferring intermediate-high level NRTI or INSTI resistance (score ≥30, Stanford HIV Drug Resistance Algorithm v.7.0.1). First-year resistance rates and 95% confidence intervals (95% CI) were estimated for 'any' (INSTI or NRTI) resistance using Poisson regression. The relationship between any emergent resistance and explanatory variables was modeled by Cox proportional hazards. RESULTS: There were 270 raltegravir, 323 elvitegravir and 392 dolutegravir-treated persons who were predominantly male (77%), antiretroviral therapy (ART)-experienced (81%), with low prevalence of preexisting drug resistance (16%). INSTI and NRTI resistance emerged in both ART-experienced and ART-naive persons (including dolutegravir-treated ART-naive), with no statistically significant differences in 'any' resistance rates (95% CI) between INSTIs: raltegravir 3.80 (1.90, 7.60), elvitegravir 2.37 (1.06, 5.27) and dolutegravir 1.48 (0.62, 3.55)/100 person-years. The strongest factors associated with emergent resistance were CD4 less than 200 cells/µl, adjusted hazard ratio (95% CI) 10.46 (4.67, 23.41) and less than 80% adherence to the INSTI regimen hazard ratio 2.52 (1.11, 5.71). CONCLUSION: Incident drug resistance rates were low with 'real-world' use of INSTI-based regimens. However, incomplete ART adherence and low CD4 cell count were associated with increased resistance rates regardless of which INSTI was prescribed. Provide adherence support and monitor for drug resistance.

Post-marketing experience with nevirapine extended release (XR) tablets: effectiveness and tolerability in a population-based cohort in British Columbia, Canada.

BACKGROUND: Nevirapine 400 mg extended release tablets (nevirapine-XR) are a once-daily alternative to nevirapine 200 mg immediate release tablets (nevirapine-IR). Study objectives were to describe the effectiveness and tolerability of nevirapine-XR in clinical practice and, for patients who switched from once daily 2×200 mg nevirapine-IR to nevirapine-XR, compare virological suppression and plasma nevirapine concentrations during each treatment period. METHODS: HIV-1-infected adults entered the study cohort if they initiated nevirapine-XR in British Columbia (BC) Canada between 1 April 2012 and 30 September 2012 and were followed until 30 September 2013. Demographic and clinical variables were abstracted from the BC Centre for Excellence in HIV/AIDS databases. Patients who switched from once daily nevirapine-IR to nevirapine-XR were monitored for 6 months pre- and post-switch with comparison of virological suppression (McNeamer's test) and median random plasma nevirapine concentrations (Wilcoxon-Mann-Whitney test) in each period. RESULTS: The 536 nevirapine-XR-treated patients were 96% male, median (IQR) age 49.9 (44.0-56.9) years. Median follow-up was 15.6 (14.7-16.5) months, with 474/536 (88%) maintaining virological suppression. Emergent drug resistance developed in 5/536 (1%), adverse drug reactions in 17/536 (3%) and, although 31/536 (6%) reported 'whole' tablets in their stools, this was not associated with adverse outcomes. Among the 305 patients who switched from nevirapine-IR to nevirapine-XR, median (IQR) random plasma nevirapine concentration was higher during nevirapine-IR 5,000 (3,690-6,090) ng/ml than nevirapine-XR 3,930 (3,050-5,150) ng/ml (P<0.001), but there was no difference in virological suppression, 89% and 87% respectively (P=0.414). CONCLUSIONS: This post-marketing study affirms the effectiveness and tolerability of nevirapine-XR as an alternative to nevirapine-IR in adults.

Evaluation of treatment tolerability, satisfaction and laboratory parameters in HIV+ patients switching from ritonavir capsule to tablet formulation.

BACKGROUND: This study evaluated treatment satisfaction, gastrointestinal tolerability, depressive symptoms and alterations in laboratory parameters before and after switching from ritonavir capsule to tablet formulation. METHODS: HIV+ adults switching from ritonavir capsules to tablets were eligible for the study. The HIV Treatment Satisfaction Questionnaire (HIVTSQ), Gastrointestinal Symptom Rating Scale (GSRS) and CES-D Depression inventory were self-administered before, and 3-4 months after switching. Results of laboratory tests within three months of each questionnaire were collected. A subset underwent plasma drug level sampling. Wilcoxon signed rank sum test was used for comparison of continuous variables and McNemar's test for dichotomised data. RESULTS: Most of the 71 participants were Caucasian men, median age 51 years. Participants were taking ritonavir in combination with either atazanavir (n=48 [67.6%]), darunavir (n=18 [25.4%]), fosamprenavir (n=3 [4.2%]) or saquinavir (n=2 [2.8%]). In general after the switch to tablets, participants reported improved treatment satisfaction (median [interquartile range] HIVTSQ score 53/60 [48, 58] after vs 49/60 [45, 54] before, p <0.001), fewer gastrointestinal symptoms (GSRS score 4/45 [1, 9] vs 5/45 [3,13], p < 0.001) and had higher HDL cholesterol (1.22 mmol/L [1.07, 1.45] vs 1.09 mmol/L [0.90,1.32], p = 0.003) and lower total cholesterol/HDL ratio (3.82 [3.05, 4.40] vs 4.23 [3.45, 4.84], p<0.001). There were no significant changes in plasma viral load, CD4 counts, depression scores, or atazanavir or ritonavir trough levels. CONCLUSION: Results of this study suggest that the newer tablet formulation of ritonavir is better tolerated and has fewer gastrointestinal side effects than the older capsule formulation.