Prevalence of Emergent Dolutegravir Resistance Mutations in People Living with HIV: A Rapid Scoping Review.

BACKGROUND: Dolutegravir (DTG) is a cornerstone of global antiretroviral (ARV) therapy (ART) due to its high efficacy and favorable tolerability. However, limited data exist regarding the risk of emergent integrase strand transfer inhibitor (INSTI) drug-resistance mutations (DRMs) in individuals receiving DTG-containing ART. METHODS: We performed a PubMed search using the term "Dolutegravir", last updated 18 December 2023, to estimate the prevalence of VF with emergent INSTI DRMs in people living with HIV (PLWH) without previous VF on an INSTI who received DTG-containing ART. RESULTS: Of 2131 retrieved records, 43 clinical trials, 39 cohorts, and 6 cross-sectional studies provided data across 6 clinical scenarios based on ART history, virological status, and co-administered ARVs: (1) ART-naïve PLWH receiving DTG plus two NRTIs; (2) ART-naïve PLWH receiving DTG plus lamivudine; (3) ART-experienced PLWH with VF on a previous regimen receiving DTG plus two NRTIs; (4) ART-experienced PLWH with virological suppression receiving DTG plus two NRTIs; (5) ART-experienced PLWH with virological suppression receiving DTG and a second ARV; and (6) ART-experienced PLWH with virological suppression receiving DTG monotherapy. The median proportion of PLWH in clinical trials with emergent INSTI DRMs was 1.5% for scenario 3 and 3.4% for scenario 6. In the remaining four trial scenarios, VF prevalence with emergent INSTI DRMs was ≤0.1%. Data from cohort studies minimally influenced prevalence estimates from clinical trials, whereas cross-sectional studies yielded prevalence data lacking denominator details. CONCLUSIONS: In clinical trials, the prevalence of VF with emergent INSTI DRMs in PLWH receiving DTG-containing regimens has been low. Novel approaches are required to assess VF prevalence with emergent INSTI DRMs in PLWH receiving DTG in real-world settings.

Human immunodeficiency virus 1 5'-leader mutations in plasma viruses before and after the development of reverse transcriptase inhibitor-resistance mutations.

Human immunodeficiency virus 1 (HIV-1) reverse transcriptase (RT) initiation depends on interaction between viral 5'-leader RNA, RT and host tRNA3Lys. Therefore, we sought to identify co-evolutionary changes between the 5'-leader and RT in viruses developing RT-inhibitor resistance mutations. We sequenced 5'-leader positions 37-356 of paired plasma virus samples from 29 individuals developing the nucleoside RT inhibitor (NRTI)-resistance mutation M184V, 19 developing a non-nucleoside RT inhibitor (NNRTI)-resistance mutation and 32 untreated controls. 5'-Leader variants were defined as positions where ≥20 % of next-generation sequencing (NGS) reads differed from the HXB2 sequence. Emergent mutations were defined as nucleotides undergoing a ≥4-fold change in proportion between baseline and follow-up. Mixtures were defined as positions containing ≥2 nucleotides each present in ≥20 % of NGS reads. Among 80 baseline sequences, 87 positions (27.2 %) contained a variant; 52 contained a mixture. Position 201 was the only position more likely to develop a mutation in the M184V (9/29 vs 0/32; P=0.0006) or NNRTI-resistance (4/19 vs 0/32; P=0.02; Fisher's exact test) groups than the control group. Mixtures at positions 200 and 201 occurred in 45.0 and 28.8 %, respectively, of baseline samples. Because of the high proportion of mixtures at these positions, we analysed 5'-leader mixture frequencies in two additional datasets: five publications reporting 294 dideoxyterminator clonal GenBank sequences from 42 individuals and six National Center for Biotechnology Information (NCBI) BioProjects reporting NGS datasets from 295 individuals. These analyses demonstrated position 200 and 201 mixtures at proportions similar to those in our samples and at frequencies several times higher than at all other 5'-leader positions. Although we did not convincingly document co-evolutionary changes between RT and 5'-leader sequences, we identified a novel phenomenon, wherein positions 200 and 201 immediately downstream of the HIV-1 primer binding site exhibited an extraordinarily high likelihood of containing a nucleotide mixture. Possible explanations for the high mixture rates are that these positions are particularly error-prone or provide a viral fitness advantage.

Recommendations on data sharing in HIV drug resistance research.

• Human immunodeficiency virus (HIV) drug resistance has implications for antiretroviral treatment strategies and for containing the HIV pandemic because the development of HIV drug resistance leads to the requirement for antiretroviral drugs that may be less effective, less well-tolerated, and more expensive than those used in first-line regimens. • HIV drug resistance studies are designed to determine which HIV mutations are selected by antiretroviral drugs and, in turn, how these mutations affect antiretroviral drug susceptibility and response to future antiretroviral treatment regimens. • Such studies collectively form a vital knowledge base essential for monitoring global HIV drug resistance trends, interpreting HIV genotypic tests, and updating HIV treatment guidelines. • Although HIV drug resistance data are collected in many studies, such data are often not publicly shared, prompting the need to recommend best practices to encourage and standardize HIV drug resistance data sharing. • In contrast to other viruses, sharing HIV sequences from phylogenetic studies of transmission dynamics requires additional precautions as HIV transmission is criminalized in many countries and regions. • Our recommendations are designed to ensure that the data that contribute to HIV drug resistance knowledge will be available without undue hardship to those publishing HIV drug resistance studies and without risk to people living with HIV.

Treatment Emergent Dolutegravir Resistance Mutations in Individuals Naïve to HIV-1 Integrase Inhibitors: A Rapid Scoping Review.

Background: Dolutegravir (DTG)-based antiretroviral therapy (ART) rarely leads to virological failure (VF) and drug resistance in integrase strand transfer inhibitor (INSTI)-naïve persons living with HIV (PLWH). As a result, limited data are available on INSTI-associated drug resistance mutations (DRMs) selected by DTG-containing ART regimens. Methods: We reviewed studies published through July 2023 to identify those reporting emergent major INSTI-associated DRMs in INSTI-naïve PLWH receiving DTG and those containing in vitro DTG susceptibility results using a standardized assay. Results: We identified 36 publications reporting 99 PLWH in whom major nonpolymorphic INSTI-associated DRMs developed on a DTG-containing regimen and 21 publications containing 269 in vitro DTG susceptibility results. DTG-selected DRMs clustered into four largely non-overlapping mutational pathways characterized by mutations at four signature positions: R263K, G118R, N155H, and Q148H/R/K. Eighty-two (82.8%) viruses contained just one signature DRM, including R263K (n = 40), G118R (n = 24), N155H (n = 9), and Q148H/R/K (n = 9). Nine (9.1%) contained ≥1 signature DRM, and eight (8.1%) contained just other DRMs. R263K and G118R were negatively associated with one another and with N155H and Q148H/K/R. R263K alone conferred a median 2.0-fold (IQR: 1.8-2.2) reduction in DTG susceptibility. G118R alone conferred a median 18.8-fold (IQR:14.2-23.4) reduction in DTG susceptibility. N155H alone conferred a median 1.4-fold (IQR: 1.2-1.6) reduction in DTG susceptibility. Q148H/R/K alone conferred a median 0.8-fold (IQR: 0.7-1.1) reduction in DTG susceptibility. Considerably higher levels of reduced susceptibility often occurred when signature DRMs occurred with additional INSTI-associated DRMs. Conclusions: Among INSTI-naïve PLWH with VF and treatment emergent INSTI-associated DRMs, most developed one of four signature DRMs, most commonly R263K or G118R. G118R was associated with a much greater reduction in DTG susceptibility than R263K.

Checklist for studies of HIV drug resistance prevalence or incidence: rationale and recommended use.

HIV drug resistance (HIVDR) is a major challenge to the effectiveness of antiretroviral therapy. Global efforts in addressing HIVDR require clear, transparent, and replicable reporting in HIVDR studies. We describe the rationale and recommended use of a checklist that should be included in reports of HIVDR incidence and prevalence. After preliminary consultations with experts on HIVDR and establishing the need for guidance on HIVDR reporting, we used a sequential, explanatory, mixed methods approach to create the checklist; together with the accompanying articles, the checklist was reviewed by the authors and validated externally. The checklist for studies on HIVDR prevalence or incidence (CEDRIC-HIV) includes 15 recommended items that would enhance transparency and facilitate interpretation, comparability, and replicability of HIVDR studies. CEDRIC-HIV will help authors of HIVDR studies prepare research reports and assist reviewers and editors in assessments of completeness of reporting. The checklist will also facilitate statistical pooling and interpretation of HIVDR data.

HIV-1 5'-Leader Mutations in Plasma Viruses Before and After the Development of Reverse Transcriptase Inhibitor-Resistance Mutations.

Background: HIV-1 RT initiation depends on interaction between viral 5'-leader RNA, RT, and host tRNA3Lys. We therefore sought to identify co-evolutionary changes between the 5'-leader and RT in viruses developing RT-inhibitor resistance mutations. Methods: We sequenced 5'-leader positions 37-356 of paired plasma virus samples from 29 individuals developing the NRTI-resistance mutation M184V, 19 developing an NNRTI-resistance mutation, and 32 untreated controls. 5'-leader variants were defined as positions where ≥20% of NGS reads differed from the HXB2 sequence. Emergent mutations were defined as nucleotides undergoing ≥4-fold change in proportion between baseline and follow-up. Mixtures were defined as positions containing ≥2 nucleotides each present in ≥20% of NGS reads. Results: Among 80 baseline sequences, 87 positions (27.2%) contained a variant; 52 contained a mixture. Position 201 was the only position more likely to develop a mutation in the M184V (9/29 vs. 0/32; p=0.0006) or NNRTI-resistance (4/19 vs. 0/32; p=0.02; Fisher's Exact Test) groups than the control group. Mixtures at positions 200 and 201 occurred in 45.0% and 28.8%, respectively, of baseline samples. Because of the high proportion of mixtures at these positions, we analyzed 5'-leader mixture frequencies in two additional datasets: five publications reporting 294 dideoxyterminator clonal GenBank sequences from 42 individuals and six NCBI BioProjects reporting NGS datasets from 295 individuals. These analyses demonstrated position 200 and 201 mixtures at proportions similar to those in our samples and at frequencies several times higher than at all other 5'-leader positions. Conclusions: Although we did not convincingly document co-evolutionary changes between RT and 5'-leader sequences, we identified a novel phenomenon, wherein positions 200 and 201, immediately downstream of the HIV-1 primer binding site exhibited an extraordinarily high likelihood of containing a nucleotide mixture. Possible explanations for the high mixture rates are that these positions are particularly error-prone or provide a viral fitness advantage.

HIV-1 Group M Capsid Amino Acid Variability: Implications for Sequence Quality Control of Genotypic Resistance Testing.

BACKGROUND: With the approval of the HIV-1 capsid inhibitor, lenacapavir, capsid sequencing will be required for managing lenacapavir-experienced individuals with detectable viremia. Successful sequence interpretation will require examining new capsid sequences in the context of previously published sequence data. METHODS: We analyzed published HIV-1 group M capsid sequences from 21,012 capsid-inhibitor naïve individuals to characterize amino acid variability at each position and influence of subtype and cytotoxic T lymphocyte (CTL) selection pressure. We determined the distributions of usual mutations, defined as amino acid differences from the group M consensus, with a prevalence ≥ 0.1%. Co-evolving mutations were identified using a phylogenetically-informed Bayesian graphical model method. RESULTS: 162 (70.1%) positions had no usual mutations (45.9%) or only conservative usual mutations with a positive BLOSUM62 score (24.2%). Variability correlated independently with subtype-specific amino acid occurrence (Spearman rho = 0.83; p < 1 × 10-9) and the number of times positions were reported to contain an HLA-associated polymorphism, an indicator of CTL pressure (rho = 0.43; p = 0.0002). CONCLUSIONS: Knowing the distribution of usual capsid mutations is essential for sequence quality control. Comparing capsid sequences from lenacapavir-treated and lenacapavir-naïve individuals will enable the identification of additional mutations potentially associated with lenacapavir therapy.

Potential role of doravirine for the treatment of HIV-1-infected persons with transmitted drug resistance.

BACKGROUND: Doravirine has a unique resistance profile but how this profile might increase its usefulness beyond first-line therapy in persons with susceptible viruses has not been well studied. We sought to determine scenarios in which doravirine would retain activity against isolates from ART-naïve persons with transmitted drug resistance (TDR) and to identify gaps in available doravirine susceptibility data. METHODS: We analyzed published in vitro doravirine susceptibility data and applied the results to 42,535 RT sequences from ART-naïve persons published between 2017 and 2021. NNRTI drug resistance mutations (DRMs) were defined as those with a Stanford HIV Drug Resistance Database doravirine penalty score either alone or in combination with other mutations. RESULTS: V106A, Y188L, F227C/L, M230L, and Y318F were associated with the greatest reductions in doravirine susceptibility. However, several NNRTI DRMs and DRM combinations lacking these canonical resistance mutations had > tenfold reduced susceptibility including G190E, one isolate with G190S, three isolates with L100I + K103N, one isolate with K103N + P225H, and isolates with L100I + K103N + V108I and K101E + Y181C + G190A. Of the 42,535 ART-naïve sequences, 3,374 (7.9%) contained a NNRTI DRM of which 2,788 (82.6%) contained 1 DRM (n = 33 distinct mutations), 426 (12.6%) contained 2 DRMs (79 distinct pairs of mutations), and 143 (4.2%) contained ≥ 3 DRMs (86 distinct mutation patterns). Among the 2,788 sequences with one DRM, 112 (4.0%) were associated with ≥ 3.0-fold reduced doravirine susceptibility while 2,625 (94.2%) were associated with < 3.0-fold reduced susceptibility. Data were not available for individual NNRTI DRMs in 51 sequences (1.8%). Among the 426 sequences with two NNRTI DRMs, 180 (42.3%) were associated with ≥ 3.0 fold reduced doravirine susceptibility while just 32 (7.5%) had < 3.0 fold reduced susceptibility. Data were not available for 214 (50.2%) sequences containing two NNRTI DRMs. CONCLUSIONS: First-line therapy containing doravirine plus two NRTIs is expected to be effective in treating most persons with TDR as more than 80% of TDR sequences had a single NNRTI DRM and as more than 90% with a single DRM were expected to be susceptible to doravirine. However, caution is required for the use of doravirine in persons with more than one NNRTI DRM even if none of the DRMs are canonical doravirine-resistance mutations.

Highly Ambiguous HIV-1 Pol Positions Encoding Multiple Amino Acids Usually Result from Antiviral or Immune Selection Pressure.

HIV-1 pol nucleotide ambiguities encoding amino acid mixtures occur commonly during population-based genotypic drug resistance testing. However, few studies have addressed the validity of sequences with fully ambiguous codons (FACs) containing codons translatable to more than four amino acids. We identified 839 published HIV-1 pol sequences with 846 FACs at 131 positions and determined their distribution relative to 215 HLA-associated pol positions (HAPs) and 84 drug-resistance positions. Among HIV-1 reverse transcriptase (RT) and protease sequences from antiretroviral therapy (ART)-naive and -experienced persons, there was a strong correlation between the likelihood a position was a FAC and that it was an HAP (Spearman's correlation coefficient rho >0.40; p < 1e-6). Among HIV-1 RT sequences from ART-experienced persons, there was a correlation between the likelihood that a position was a FAC and that it was a drug-resistance position (rho = 0.2; p = 8e-4). In the context of population-based genotypic resistance testing, FACs usually result from antiviral or immune selection pressure.

2022 update of the drug resistance mutations in HIV-1.

The 2022 edition of the IAS-USA drug resistance mutations list updates the Figure last published in September 2019. The mutations listed are those that have been identified by specific criteria for evidence and drugs described. The Figure is designed to assist practitioners to identify key mutations associated with resistance to antiretroviral drugs, and therefore, in making clinical decisions regarding antiretroviral therapy.

Sierra SARS-CoV-2 sequence and antiviral resistance analysis program.

INTRODUCTION: Although most laboratories are capable of employing established protocols to perform full-genome SARS-CoV-2 sequencing, many are unable to assess sequence quality, select appropriate mutation-detection thresholds, or report on the potential clinical significance of mutations in the targets of antiviral therapy METHODS: We describe the technical aspects and benchmark the performance of Sierra SARS-CoV-2, a program designed to perform these functions on user-submitted FASTQ and FASTA sequence files and lists of Spike mutations. Sierra SARS-CoV-2 indicates which sequences contain an unexpectedly large number of unusual mutations and which mutations are associated with reduced susceptibility to clinical stage mAbs, the RdRP inhibitor remdesivir, or the Mpro inhibitor nirmatrelvir RESULTS: To assess the performance of Sierra SARS-CoV-2 on FASTQ files, we applied it to 600 representative FASTQ sequences and compared the results to the COVID-19 EDGE program. To assess its performance on FASTA files, we applied it to nearly one million representative FASTA sequences and compared the results to the GISAID mutation annotation. To assess its performance on mutations lists, we applied it to 13,578 distinct Spike RBD mutation patterns and showed that exactly or partially matching annotations were available for 88% of patterns CONCLUSION: Sierra SARS-CoV-2 leverages previously published data to improve the quality control of submitted viral genomic data and to provide functional annotation on the impact of mutations in the targets of antiviral SARS-CoV-2 therapy. The program can be found at https://covdb.stanford.edu/sierra/sars2/ and its source code at https://github.com/hivdb/sierra-sars2.

Genotypic correlates of resistance to the HIV-1 strand transfer integrase inhibitor cabotegravir.

Cabotegravir (CAB) is an integrase strand transfer inhibitor (INSTI) formulated as a long-acting injectable drug approved for pre-exposure prophylaxis and use with a long acting rilpivirine formulation for therapy in patients with virological suppression. However, there has been no comprehensive review of the genetic mechanisms of CAB resistance. Studies reporting the selection of drug resistance mutations (DRMs) by CAB and the results of in vitro CAB susceptibility testing were reviewed. The impact of integrase mutations on CAB susceptibility was assessed using regularized regression analysis. The most commonly selected mutations in the 24 persons developing virological failure while receiving CAB included Q148R (n = 15), N155H (n = 7), and E138K (n = 5). T97A, G118R, G140 A/R/S, and R263K each developed in 1-2 persons. With the exception of T97A, G118R, and G140 A/R, these DRMs were also selected in vitro while G140R was selected in the SIV macaque model. Although these DRMs are similar to those occurring in persons receiving the related INSTI dolutegravir, Q148R was more likely to occur with CAB while G118R and R263K were more likely to occur with dolutegravir. Regularized regression analysis identified 14 DRMs significantly associated with reduced CAB susceptibility including six primary DRMs which reduced susceptibility on their own including G118R, Q148 H/K/R, N155H, and R263K, and eight accessory DRMs including M50I, L74 F/M, T97A, E138K, and G140 A/C/S. Isolates with Q148 H/K/R in combination with L74M, E138 A/K, G140 A/S, and N155H often had >10-fold reduced CAB susceptibility. M50I, L74M, and T97A are polymorphic mutations that alone did not appear to increase the risk of virological failure in persons receiving a CAB-containing regimen. Careful patient screening is required to prevent CAB from being used during active virus replication. Close virological monitoring is required to minimize CAB exposure to active replication to prevent the emergence of DRMs associated with cross-resistance to other INSTIs.

Infectious Diseases Society of America Guidelines on the Treatment and Management of Patients with COVID-19.

BACKGROUND: There are many pharmacologic therapies that are being used or considered for treatment of coronavirus disease 2019 (COVID-19), with rapidly changing efficacy and safety evidence from trials. OBJECTIVE: Develop evidence-based, rapid, living guidelines intended to support patients, clinicians, and other healthcare professionals in their decisions about treatment and management of patients with COVID-19. METHODS: In March 2020, the Infectious Diseases Society of America (IDSA) formed a multidisciplinary guideline panel of infectious disease clinicians, pharmacists, and methodologists with varied areas of expertise to regularly review the evidence and make recommendations about the treatment and management of persons with COVID-19. The process used a living guideline approach and followed a rapid recommendation development checklist. The panel prioritized questions and outcomes. A systematic review of the peer-reviewed and grey literature was conducted at regular intervals. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of evidence and make recommendations. RESULTS: Based on the most recent search conducted on May 31, 2022, the IDSA guideline panel has made 30 recommendations for the treatment and management of the following groups/populations: pre- and post-exposure prophylaxis, ambulatory with mild-to-moderate disease, hospitalized with mild-to-moderate, severe but not critical, and critical disease. As these are living guidelines, the most recent recommendations can be found online at: https://idsociety.org/COVID19guidelines. CONCLUSIONS: At the inception of its work, the panel has expressed the overarching goal that patients be recruited into ongoing trials. Since then, many trials were done which provided much needed evidence for COVID-19 therapies. There still remain many unanswered questions as the pandemic evolved which we hope future trials can answer.

Genotypic Resistance Testing of HIV-1 DNA in Peripheral Blood Mononuclear Cells.

HIV-1 DNA exists in nonintegrated linear and circular episomal forms and as integrated proviruses. In patients with plasma viremia, most peripheral blood mononuclear cell (PBMC) HIV-1 DNA consists of recently produced nonintegrated virus DNA while in patients with prolonged virological suppression (VS) on antiretroviral therapy (ART), most PBMC HIV-1 DNA consists of proviral DNA produced months to years earlier. Drug-resistance mutations (DRMs) in PBMCs are more likely to coexist with ancestral wild-type virus populations than they are in plasma, explaining why next-generation sequencing is particularly useful for the detection of PBMC-associated DRMs. In patients with ongoing high levels of active virus replication, the DRMs detected in PBMCs and in plasma are usually highly concordant. However, in patients with lower levels of virus replication, it may take several months for plasma virus DRMs to reach detectable levels in PBMCs. This time lag explains why, in patients with VS, PBMC genotypic resistance testing (GRT) is less sensitive than historical plasma virus GRT, if previous episodes of virological failure and emergent DRMs were either not prolonged or not associated with high levels of plasma viremia. Despite the increasing use of PBMC GRT in patients with VS, few studies have examined the predictive value of DRMs on the response to a simplified ART regimen. In this review, we summarize what is known about PBMC HIV-1 DNA dynamics, particularly in patients with suppressed plasma viremia, the methods used for PBMC HIV-1 GRT, and the scenarios in which PBMC GRT has been used clinically.

Susceptibility of SARS-CoV-2 Omicron Variants to Therapeutic Monoclonal Antibodies: Systematic Review and Meta-analysis.

SARS-CoV-2 Omicron variants contain many mutations in its spike receptor-binding domain, the target of all authorized monoclonal antibodies (MAbs). Determining the extent to which Omicron variants reduced MAb susceptibility is critical to preventing and treating COVID-19. We systematically reviewed PubMed and three preprint servers, last updated 11 April 2022, for the in vitro activity of authorized MAbs against the Omicron variants. Fifty-one studies were eligible, including 50 containing Omicron BA.1 susceptibility data and 17 containing Omicron BA.2 susceptibility data. The first two authorized MAb combinations, bamlanivimab/etesevimab and casirivimab/imdevimab, were largely inactive against the Omicron BA.1 and BA.2 variants. In 34 studies, sotrovimab displayed a median 4.0-fold (interquartile range [IQR]: 2.6 to 6.9) reduction in activity against Omicron BA.1, and in 12 studies, it displayed a median 17-fold (IQR: 13 to 30) reduction in activity against Omicron BA.2. In 15 studies, the combination cilgavimab/tixagevimab displayed a median 86-fold (IQR: 27 to 151) reduction in activity against Omicron BA.1, and in six studies, it displayed a median 5.4-fold (IQR: 3.7 to 6.9) reduction in activity against Omicron BA.2. In eight studies against Omicron BA.1 and six studies against Omicron BA.2, bebtelovimab displayed no reduction in activity. Disparate results between assays were common. For authorized MAbs, 51/268 (19.0%) results for wild-type control variants and 78/348 (22.4%) results for Omicron BA.1 and BA.2 variants were more than 4-fold below or 4-fold above the median result for that MAb. Highly disparate results between published assays indicate a need for improved MAb susceptibility test standardization or interassay calibration. IMPORTANCE Monoclonal antibodies (MAbs) targeting the SARS-CoV-2 spike protein are among the most effective measures for preventing and treating COVID-19. However, SARS-CoV-2 Omicron variants contain many mutations in their spike receptor-binding domains, the target of all authorized MAbs. Therefore, determining the extent to which Omicron variants reduced MAb susceptibility is critical to preventing and treating COVID-19. We identified 51 studies that reported the in vitro susceptibility of the two main Omicron variants BA.1 and BA.2 to therapeutic MAbs in advanced clinical development, including eight authorized individual MAbs and three authorized MAb combinations. We estimated the degree to which different MAbs displayed reduced activity against Omicron variants. The marked loss of activity of many MAbs against Omicron variants underscores the importance of developing MAbs that target conserved regions of spike. Highly disparate results between assays indicate the need for improved MAb susceptibility test standardization.

Public availability of HIV-1 drug resistance sequence and treatment data: a systematic review.

HIV-1 pol sequences from antiretroviral therapy (ART)-naive and ART-experienced people living with HIV-1 are fundamental to understanding the genetic correlates and epidemiology of HIV-1 drug resistance (HIVDR). To assess the public availability of HIV-1 pol sequences and ART histories of the individuals from whom sequenced viruses were obtained, we performed a systematic review of PubMed and GenBank for HIVDR studies published between 2010 and 2019 that reported HIV-1 pol sequences. 934 studies met inclusion criteria, including 461 studies of ART-naive adults, 407 of ART-experienced adults, and 66 of ART-naive and ART-experienced children. Sequences were available for 317 (68·8%) studies of ART-naive individuals, 190 (46·7%) of ART-experienced individuals, and 45 (68·2%) of children. Among ART-experienced individuals, sequences plus linked ART histories were available for 82 (20·1%) studies. Sequences were available for 21 (29·2%) of 72 clinical trials. Among journals publishing more than ten studies, the proportion with available sequences ranged from 8·3% to 86·9%. Strengthened implementation of data sharing policies is required to increase the number of studies with available HIVDR data to support the enterprise of global ART in the face of emerging HIVDR.

Spectrum of Atazanavir-Selected Protease Inhibitor-Resistance Mutations.

Ritonavir-boosted atazanavir is an option for second-line therapy in low- and middle-income countries (LMICs). We analyzed publicly available HIV-1 protease sequences from previously PI-naïve patients with virological failure (VF) following treatment with atazanavir. Overall, 1497 patient sequences were identified, including 740 reported in 27 published studies and 757 from datasets assembled for this analysis. A total of 63% of patients received boosted atazanavir. A total of 38% had non-subtype B viruses. A total of 264 (18%) sequences had a PI drug-resistance mutation (DRM) defined as having a Stanford HIV Drug Resistance Database mutation penalty score. Among sequences with a DRM, nine major DRMs had a prevalence >5%: I50L (34%), M46I (33%), V82A (22%), L90M (19%), I54V (16%), N88S (10%), M46L (8%), V32I (6%), and I84V (6%). Common accessory DRMs were L33F (21%), Q58E (16%), K20T (14%), G73S (12%), L10F (10%), F53L (10%), K43T (9%), and L24I (6%). A novel nonpolymorphic mutation, L89T occurred in 8.4% of non-subtype B, but in only 0.4% of subtype B sequences. The 264 sequences included 3 (1.1%) interpreted as causing high-level, 14 (5.3%) as causing intermediate, and 27 (10.2%) as causing low-level darunavir resistance. Atazanavir selects for nine major and eight accessory DRMs, and one novel nonpolymorphic mutation occurring primarily in non-B sequences. Atazanavir-selected mutations confer low-levels of darunavir cross resistance. Clinical studies, however, are required to determine the optimal boosted PI to use for second-line and potentially later line therapy in LMICs.

Selection Analysis Identifies Clusters of Unusual Mutational Changes in Omicron Lineage BA.1 That Likely Impact Spike Function.

Among the 30 nonsynonymous nucleotide substitutions in the Omicron S-gene are 13 that have only rarely been seen in other SARS-CoV-2 sequences. These mutations cluster within three functionally important regions of the S-gene at sites that will likely impact (1) interactions between subunits of the Spike trimer and the predisposition of subunits to shift from down to up configurations, (2) interactions of Spike with ACE2 receptors, and (3) the priming of Spike for membrane fusion. We show here that, based on both the rarity of these 13 mutations in intrapatient sequencing reads and patterns of selection at the codon sites where the mutations occur in SARS-CoV-2 and related sarbecoviruses, prior to the emergence of Omicron the mutations would have been predicted to decrease the fitness of any virus within which they occurred. We further propose that the mutations in each of the three clusters therefore cooperatively interact to both mitigate their individual fitness costs, and, in combination with other mutations, adaptively alter the function of Spike. Given the evident epidemic growth advantages of Omicron overall previously known SARS-CoV-2 lineages, it is crucial to determine both how such complex and highly adaptive mutation constellations were assembled within the Omicron S-gene, and why, despite unprecedented global genomic surveillance efforts, the early stages of this assembly process went completely undetected.

Coronavirus Resistance Database (CoV-RDB): SARS-CoV-2 susceptibility to monoclonal antibodies, convalescent plasma, and plasma from vaccinated persons.

As novel SARS-CoV-2 variants with different patterns of spike protein mutations have emerged, the susceptibility of these variants to neutralization by antibodies has been rapidly assessed. However, neutralization data are generated using different approaches and are scattered across different publications making it difficult for these data to be located and synthesized. The Stanford Coronavirus Resistance Database (CoV-RDB; https://covdb.stanford.edu) is designed to house comprehensively curated published data on the neutralizing susceptibility of SARS-CoV-2 variants and spike mutations to monoclonal antibodies (mAbs), convalescent plasma (CP), and vaccinee plasma (VP). As of December 31, 2021, CoV-RDB encompassed 257 publications including 91 (35%) containing 9,070 neutralizing mAb susceptibility results, 131 (51%) containing 16,773 neutralizing CP susceptibility results, and 178 (69%) containing 33,540 neutralizing VP results. The database also records which spike mutations are selected during in vitro passage of SARS-CoV-2 in the presence of mAbs and which emerge in persons receiving mAbs as treatment. The CoV-RDB interface interactively displays neutralizing susceptibility data at different levels of granularity by filtering and/or aggregating query results according to one or more experimental conditions. The CoV-RDB website provides a companion sequence analysis program that outputs information about mutations present in a submitted sequence and that also assists users in determining the appropriate mutation-detection thresholds for identifying non-consensus amino acids. The most recent data underlying the CoV-RDB can be downloaded in its entirety from a GitHub repository in a documented machine-readable format.

Adherence to contemporary antiretroviral treatment regimens and impact on immunological and virologic outcomes in a US healthcare system.

BACKGROUND: Only a few recent reports have examined longitudinal adherence patterns in US clinics and its impact on immunological and virological outcomes among large cohorts initiating contemporary antiretroviral therapy (ART) in US clinics. METHODS: We followed all persons with HIV (PLWH) in a California clinic population initiating ART between 2010 and 2017. We estimated longitudinal adherence for each PLWH by calculating the medication possession ratio within multiple 6-month intervals using pharmacy refill records. RESULTS: During the study, 2315 PWLH were followed for a median time of 210.8 weeks and only 179 (7.7%) were lost-to-follow-up. The mean adherence was 84.9%. Age (Hazard Ratio (HR): (95% confidence interval): 1.25 (1.20-1.31) per 10-year increase) and Black race (HR: 0.62 (0.53-0.73) vs. White) were associated with adherence in the cohort. A 10% percent increase in adherence increased the odds of being virally suppressed by 37% (OR and 95% CI: 1.37 [1.33-1.41]) and was associated with an increase in mean CD4 count by 8.54 cells/ul in the next 6-month interval (p-value <0.0001). CONCLUSIONS: Our study shows that despite large improvements in retention in care, demographic disparities in adherence to ART persist. Adherence was lower among younger patients and black patients. Our study confirmed the strong association between adherence to ART and viral suppression but could only establish a weak association between adherence and CD4 count. These findings reaffirm the importance of adherence and retention in care and further highlight the need for tailored patient-centered HIV Care Models as a strategy to improve PLWH's outcomes.