Immune Escape Mutations Research Articles

Immune escape mutations selected by neutralizing antibodies in natural HIV-1 infection can alter coreceptor usage repertoire of the transmitted/founder virus

The ability of HIV-1 to evade neutralizing antibodies (NAbs) in vivo is well demonstrated, but the impact of NAb escape mutations on HIV-1 phenotype other than immune escape itself has rarely been studied. Here, we show that immune escape mutations selected by V3-glycan specific NAbs in vivo can alter coreceptor usage repertoire of the transmitted/founder (T/F) HIV-1. In a participant developed V3-glycan NAb response, naturally selected escape mutations at the V3 N301 and N332 glycan sites abrogated CCR8 usage while conferred APJ usage on the cognate T/F strain. Mutations at the N301 glycan also impaired CCR3 usage and partially compromised the efficiency in using CCR5, which could be fully restored by a single escape mutation at the N332 glycan site. Our study demonstrates the link between NAb escape and coreceptor usage alteration in natural HIV-1 infection and indicates that NAb response could drive virus entry tropism evolution in vivo.

A CLUSTER OF SARS‐COV‐2 DELTA VARIANT OF CONCERN ADDITIONALLY HARBORING F490S, NORTHERN LOMBARDY, ITALY

The Delta variant of concern (VOC) of SARS-CoV-2 has become dominant worldwide. In this article, we report a cluster caused by B.1.617.2 harboring the additional mutation of concern (MOC) F490S. We observed that 5 fully vaccinated subjects aged between 47 and 84 years were infected with this variant. The immune escape mutation F490S, first identified in the Lambda VOI, appears to impair vaccine efficacy and is rapidly increasing in prevalence worldwide.

Lessons from mouse models of MPN.

Over the past decades, a variety of MPN mouse models have been developed to express in HSC the main mutations identified in patients: JAK2V617F, CALRdel52 or ins5 and MPLW515L. These models mimic quite faithfully human PV or ET with their natural evolutions into MF and their hemostasis complications, demonstrating the driver function of these mutations in MPN. Here, we review these models and show how they have improved our general understanding of MPN regarding (1) the mechanisms of fibrosis, thrombosis/hemorrhages and disease initiation, (2) the roles of additional mutations and signaling pathways in disease progression and (3) the preclinical development of novel therapies. We also address controversial results between these models and remind how these models may differ from human MPN onset and also how basically mice are not humans, encouraging caution when one draw lessons from mice to humans. Furthermore, the contribution of germline genetic predisposition, HSC and niche aging, metabolic, oxidative, replicative or genotoxic stress, inflammation, immune escape and additional mutations need to be considered in further investigations to encompass the full complexity of human MPN in mice.

The dynamic changes of HBV quasispecies diversity in infancy after immunoprophylaxis failure: a prospective cohort study

BackgroundPrevious works have observed that younger infants with chronic hepatitis B virus (HBV) infection are more responsive to antiviral treatment. However, the underlying mechanism remains unclear. In this study, the dynamic changes of HBV quasispecies in infants with immunoprophylaxis failure were investigated to provide virological explanations for clinical management on infantile antiviral therapy.MethodsThirteen 7-month-old infants with immunoprophylaxis failure and their mothers were enrolled from a prospective cohort, and 8 of them were followed up to 3 years old. The sequences of HBV quasispecies were analyzed by the full-length genome clone-based sequencing, and compared among mothers and their infants at different ages.ResultsThe results revealed that the complexity, mutation frequency and genetic distance of HBV quasispecies decreased significantly at full-length, partial open reading frames and regulatory regions of HBV genome at nucleotide level in 7-month-old infants comparing with their mothers, whereas increased significantly to near the maternal level when infants grew up to 3 years old. Furthermore, similar changes were also found in Core, PreS2, RT and P regions of HBV genome at amino acid level, especially for potential NAs-resistant mutants in RT region and immune-escape mutants in Core and PreS2 regions.ConclusionsThis study uncovered the evolution of HBV quasispecies in infancy after mother-to-child transmission, which may provide the virological evidence for explaning that younger children are more responsive to antiviral therapy.

Understanding the Secret of SARS-CoV-2 Variants of Concern/Interest and Immune Escape.

The global pandemic of the coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), places a heavy burden on global public health. Four SARS-CoV-2 variants of concern including B.1.1.7, B.1.351, B.1.617.2, and P.1, and two variants of interest including C.37 and B.1.621 have been reported to have potential immune escape, and one or more mutations endow them with worrisome epidemiologic, immunologic, or pathogenic characteristics. This review introduces the latest research progress on SARS-CoV-2 variants of interest and concern, key mutation sites, and their effects on virus infectivity, mortality, and immune escape. Moreover, we compared the effects of various clinical SARS-CoV-2 vaccines and convalescent sera on epidemic variants, and evaluated the neutralizing capability of several antibodies on epidemic variants. In the end, SARS-CoV-2 evolution strategies in different transmission stages, the impact of different vaccination strategies on SARS-CoV-2 immune escape, antibody therapy strategies and COVID-19 epidemic control prospects are discussed. This review will provide a systematic and comprehensive understanding of the secret of SARS-CoV-2 variants of interest/concern and immune escape.

Simultaneous evaluation of antibodies that inhibit SARS-CoV-2 variants via multiplex assay.

The SARS-CoV-2 receptor binding domain (RBD) is both the principal target of neutralizing antibodies and one of the most rapidly evolving domains, which can result in the emergence of immune escape mutations, limiting the effectiveness of vaccines and antibody therapeutics. To facilitate surveillance, we developed a rapid, high-throughput, multiplex assay able to assess the inhibitory response of antibodies to 24 RBD natural variants simultaneously. We demonstrate how this assay can be implemented as a rapid surrogate assay for functional cell-based serological methods to measure the SARS-CoV-2 neutralizing capacity of antibodies at the angiotensin-converting enzyme 2–RBD (ACE2-RBD) interface. We describe the enhanced affinity of RBD variants N439K, S477N, Q493L, S494P, and N501Y to the ACE2 receptor and demonstrate the ability of this assay to bridge a major gap for SARS-CoV-2 research, informing selection of complementary monoclonal antibody candidates and the rapid identification of immune escape to emerging RBD variants following vaccination or natural infection.

SARS-CoV-2 Clinical Outcome in Domestic and Wild Cats: A Systematic Review.

Simple SummaryIn view of the current global situation due to the COVID-19 pandemic and considering the evidence that SARS-CoV-2 has the ability to infect multiple species, this work was aimed at identifying the clinical signs of SARS-CoV-2 infection in domestic and wild felids. Our results evince that the signs developed in felids show similar progression to those occurring in humans, suggesting a relationship between the viral cycle and target tissues of the virus in different species. Recently, it has been proved that SARS-CoV-2 has the ability to infect multiple species. This work was aimed at identifying the clinical signs of SARS-CoV-2 infection in domestic and wild felids. A PRISMA-based systematic review was performed on case reports on domestic and wild cats, reports on experimental infections, case reports in databases, preprints and published press releases. Descriptive statistical analysis of the data was performed. A total of 256 articles, 63 detailed official reports and 2 press articles on SARS-CoV-2 infection in domestic and wild cats were analyzed, of which 19 articles and 65 reports were finally included. In domestic cats, most cats’ infections are likely to be asymptomatic, and 46% of the reported infected animals were symptomatic and predominantly presented respiratory signs such as sneezing and coughing. In wild felines, respiratory clinical signs were most frequent, and up to 96.5% of the reported affected animals presented coughing. It is noteworthy that, to date, symptomatic animals with SARS-CoV-2 infection have been reported to belong to two different subfamilies (Phanterinae and Felinae), with up to five different felid species affected within the Felidae family. Reported results evince that the signs developed in felids show similar progression to those occurring in humans, suggesting a relationship between the viral cycle and target tissues of the virus in different species. While viral transmission to humans in contact with animal populations has not been reported, spill-back could result in the emergence of immune-escape mutants that might pose a risk to public health. Despite the clear results in the identification of the typical clinical picture of SARS-CoV-2 infection in felines, the number of detailed academic reports and papers on the subject is scarce. Therefore, further description of these cases will allow for more accurate and statistically robust clinical approaches in the future.

The release of viral particle from hepatitis B virus infected hepatocytes is inhibited by recombinant hepatitis B virus immunoglobulin (lenvervimab)

Potent and relatively low cost hepatitis B immunoglobulin (HBIG) could be good alternatives by overcoming the drawbacks of recent regimen and recombinant monoclonal HBIG (lenvervimab) has been reported the consistent avidity of variety to cloned S antigens including the immune escape mutant G145R and it did not interfere with the antibody binding in hepatitis B virus (HBV) with mutations of the S gene sequence which makes drug resistance to NA. We investigated the action of intracellularly located lenvervimab in HBV infected cells which is incompletely understood yet. We used five human hepatoma cell lines; Huh7, HepG2 as HBV negative and PLC/PRF/5, HepG2.2.15, and Hep3B expressing HBsAg. and various intracellular orgarnells markers; endosome (Rab5), autophagy marker (LC3) , anti-calnexin (ER), giantin (golgi), multivesicular body (Rab7). Immunofluorescence images were used to investigate the intracellular locations of lenvervimab and HBsAg. Western blot and PEG down, ELISA were used for protein analysis. Lenvervimab was co-localized with Rab5 (early endosome marker) and and induces autophagosome but not autolysis. HBsAg and Lenvervimab were co-localized with making precipitations in cytoplasm and these precipitations were not co-localized with ER and golgi marker. Rab7 (multivesicular body marker) and lenvervimab, HBsAg were co-localized in PLC/PRF/5. The release of viral particle is suppressed by lenvervimab with antigen-antibody reaction in multivesicular body.

Detection of Q129H Immune Escape Mutation in Apparently Healthy Hepatitis B Virus Carriers in Southwestern Nigeria.

As the global effort to eradicate hepatitis B continues, immune escape mutations (IEMs) and drug resistance mutations (DRMs) affecting its diagnosis, treatment, and prevention are compromising this goal. However, knowledge about the prevalence and circulation of these mutations in Nigeria is scarce. Serum samples (n = 199) from apparently healthy prospective blood donors, pregnant women, and individuals presenting with fever in southwestern Nigeria were analyzed for the presence of IEMs and DRMs by means of nested PCR in the HBV S (HBs) and HBV polymerase (Pol) genes, followed by phylogenetic and mutational analyses. In total, 25.1% (n = 50/199) of samples were positive for HBV, as measured by PCR. In 41 samples (20.6%), both fragments could be amplified, whereas the HBs gene and the Pol gene fragment alone were detected in 0.5% (n = 1/199) and 4% (n = 8/199) of samples, respectively. Sequences were successfully obtained for all 42 HBs gene fragments but for only 31/49 Pol gene fragments (totaling 73 sequences from 44 individuals). All sequences were identified as HBV genotype E. IEMs were present in 18.2% (n = 8/44) of the sequences of HBV-positive individuals with available sequences. IEM Q129H was detected in eight out of the 44 (18.2%) HBV isolates sequenced in this study; however, no DRMs were observed. This study confirms the circulation of HBV IEMs and reports the presence of Q129H IEM for the first time in Nigeria. Intensified research on the dynamics of IEM is necessary in order to enhance the elimination of HBV.

Evolution and phenotypic characterization of whole HBV genome in compliant patients experiencing unexplained entecavir treatment failure

Entecavir treatment failure can be observed in compliant patients despite an absence of detectable resistance mutations by Pol/RT Sanger sequencing. We hypothesized that these unexplained treatment failures could rely on other mechanisms of viral resistance, especially on mutations selected outside of the Pol/RT domain. Partial virological response to entecavir was observed in three patients treated with immunosuppressive drugs, without selection of Pol/RT resistance mutations. Mutations selected in the whole HBV genome during entecavir treatment and potentially associated with resistance were searched for using deep sequencing and characterized using a phenotypic resistance assay. Mutations Q206K (pre-core/core), Q120K (pre-S1/pre-S2, T-cell epitope) and A300E (spacer domain) were selected during entecavir treatment in patient #1 but were not associated with an increased level of resistance to entecavir or an increase in HBV replication capacity. Core promoter mutations T1753G, A1762T and G1764A were present as major mutations before and after treatment in patient #1. HBs Ag immune escape mutations were present as major mutations before and after treatment in patients #2 (sK122R, sT126I, sP127S and sG145R) and #3 (sM133I). We demonstrated that PVR to entecavir does not require selection of any resistance mutation in the whole HBV genome. Our results demonstrate that major mutations can be selected outside of the Pol/RT domain before or during entecavir treatment. These mutations could contribute to entecavir treatment failure by other mechanisms than an increased level of resistance.

Recurrent emergence of SARS-CoV-2 spike deletion H69/V70 and its role in the Alpha variant B.1.1.7.

SummaryWe report severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike ΔH69/V70 in multiple independent lineages, often occurring after acquisition of receptor binding motif replacements such as N439K and Y453F, known to increase binding affinity to the ACE2 receptor and confer antibody escape. In vitro, we show that, although ΔH69/V70 itself is not an antibody evasion mechanism, it increases infectivity associated with enhanced incorporation of cleaved spike into virions. ΔH69/V70 is able to partially rescue infectivity of spike proteins that have acquired N439K and Y453F escape mutations by increased spike incorporation. In addition, replacement of the H69 and V70 residues in the Alpha variant B.1.1.7 spike (where ΔH69/V70 occurs naturally) impairs spike incorporation and entry efficiency of the B.1.1.7 spike pseudotyped virus. Alpha variant B.1.1.7 spike mediates faster kinetics of cell-cell fusion than wild-type Wuhan-1 D614G, dependent on ΔH69/V70. Therefore, as ΔH69/V70 compensates for immune escape mutations that impair infectivity, continued surveillance for deletions with functional effects is warranted.

Bamlanivimab Treatment Leads to Rapid Selection of Immune Escape Variant Carrying the E484K Mutation in a B.1.1.7-Infected and Immunosuppressed Patient

To the Editor—Kumar et al [1] reported on the role of single bamlanivimab in preventing hospitalization associated with coronavirus disease 2019 (COVID-19). There is scarce evidence of prevalence of emergent variants in patients treated with bamlanivimab [2]. But very little is known about treatment-emergent variants in the B.1.1.7 lineage, which is by now the dominant strain throughout Europe and North America. We hereby report the selection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immune escape mutations in a B.1.1.7 variant 7 days after administration of single bamlanivimab in a patient with deeply impaired cellular immunity (Figure 1). The patient newly diagnosed with acute myeloid leukemia first tested positive for SARS-CoV-2 at day 11 after the start of chemotherapy. Initially, the cycle threshold (Ct) was above 30 and melting point analysis at day 15 suggested B.1.1.7 as the causative agent of this...

One dose or two?

Coronavirus For two-dose vaccines against severe acute respiratory syndrome coronavirus 2, some jurisdictions have decided to delay the second dose to rapidly get the vaccine into more people. The consequences of deviating from manufacturer-prescribed dosing regimens are unknown but will depend on the strength of immune responses to the vaccines. Saad-Roy et al. took a modeling approach to tackling the inevitable uncertainties facing vaccine rollout. The authors found that although one-dose strategies generally reduce infections in the short term, in the long term, the outcome depends on immune robustness. A one-dose strategy may increase the potential for antigenic evolution if immune responses are suboptimal and the virus continues to replicate in some vaccinated people, potentially leading to immune-escape mutations. It is critical to gather serological data from vaccinated people and, to avoid negative outcomes, to ramp up vaccination efforts worldwide. Science , this issue p. [363][1] [1]: /lookup/doi/10.1126/science.abg8663

Adenovirus-vectored T cell vaccine for hepacivirus shows reduced effectiveness against a CD8 T cell escape variant in rats.

There is an urgent need for a vaccine to prevent chronic infection by hepatitis C virus (HCV) and its many genetic variants. The first human vaccine trial, using recombinant viral vectors that stimulate pan-genotypic T cell responses against HCV non-structural proteins, failed to demonstrate efficacy despite significant preclinical promise. Understanding the factors that govern HCV T cell vaccine success is necessary for design of improved immunization strategies. Using a rat model of chronic rodent hepacivirus (RHV) infection, we assessed the impact of antigenic variation and immune escape upon success of a conceptually analogous RHV T cell vaccine. Naïve Lewis rats were vaccinated with a recombinant human adenovirus expressing RHV non-structural proteins (NS)3-5B and later challenged with a viral variant containing immune escape mutations within major histocompatibility complex (MHC) class I-restricted epitopes (escape virus). Whereas 7 of 11 (64%) rats cleared infection caused by wild-type RHV, only 3 of 12 (25%) were protected against heterologous challenge with escape virus. Uncontrolled replication of escape virus was associated with durable CD8 T cell responses targeting escaped epitopes alone. In contrast, clearance of escape virus correlated with CD4 T cell helper immunity and maintenance of CD8 T cell responses against intact viral epitopes. Interestingly, clearance of wild-type RHV infection after vaccination conferred enhanced protection against secondary challenge with escape virus. These results demonstrate that the efficacy of an RHV T cell vaccine is reduced when challenge virus contains escape mutations within MHC class I-restricted epitopes and that failure to sustain CD8 T cell responses against intact epitopes likely underlies immune failure in this setting. Further investigation of the immune responses that yield protection against diverse RHV challenges in this model may facilitate design of broadly effective HCV vaccines.

Occult and active hepatitis B virus detection in donated blood in São Paulo, Brazil.

The present study determined the HBV antigen, antibody, and DNA status in blood donations deemed to be HBV positive. Individuals with an occult HBV infection (OBI), defined as being positive for HBV DNA but negative for HBV surface antigen (HBsAg), as well as those with active infection (HBsAg-positive), were identified and characterized. From a total pool if 198,363 blood donations, we evaluated in a cross-sectional study, 1106 samples that were positive in screening tests for antibody to HBV core antigen (HBcAb), HBsAg, and/or HBV DNA by nucleic acid testing (NAT-HBV). The presence of genetic variants in the HBV pol/S gene in individuals with an active HBV infection was also determined. OBIs were detected in six of 976 samples (0.6%) that were positive only for HBcAb. The rate of HBV active infection was 0.024% (48/198,363) and there was a predominance of HBV sub-genotype A1 (62.2%, 28/45), followed by D3 (17.8%, 8/45). Mutations in the S gene were found in 57.8% (26/45) and immune escape mutations in 37.8% (17/45) of active HBV-infected donors. Among them, T123N, G145A, and D144G high-impact immune escape mutations were identified. Highly sensitive molecular tests improve the capacity to detect OBIs. When NAT is performed in pooled samples, HBcAb test has value in the detection of donors with OBI and improves transfusion safety. Mutations in the S gene are frequent in HBsAg-positive blood, including those associated with diagnostic failure and vaccine escape mutations.

SARS-CoV-2 Variant of Concern 202012/01 Has about Twofold Replicative Advantage and Acquires Concerning Mutations.

The novel SARS-CoV-2 Variant of Concern (VOC)-202012/01 (also known as B.1.1.7), first collected in United Kingdom on 20 September 2020, is a rapidly growing lineage that in January 2021 constituted 86% of all SARS-CoV-2 genomes sequenced in England. The VOC has been detected in 40 out of 46 countries that reported at least 50 genomes in January 2021. We have estimated that the replicative advantage of the VOC is in the range 1.83–2.18 [95% CI: 1.71–2.40] with respect to the 20A.EU1 variant that dominated in England in November 2020, and in range 1.65–1.72 [95% CI: 1.46–2.04] in Wales, Scotland, Denmark, and USA. As the VOC strain will likely spread globally towards fixation, it is important to monitor its molecular evolution. We have estimated growth rates of expanding mutations acquired by the VOC lineage to find that the L18F substitution in spike has initiated a fast growing VOC substrain. The L18F substitution is of significance because it has been found to compromise binding of neutralizing antibodies. Of concern are immune escape mutations acquired by the VOC: E484K, F490S, S494P (in the receptor binding motif of spike) and Q677H, Q675H (in the proximity of the polybasic cleavage site at the S1/S2 boundary). These mutants may hinder efficiency of existing vaccines and expand in response to the increasing after-infection or vaccine-induced seroprevalence.

Non-synonymous Substitutions in HIV-1 GAG Are Frequent in Epitopes Outside the Functionally Conserved Regions and Associated With Subtype Differences.

In 2019, 38 million people lived with HIV-1 infection resulting in 690,000 deaths. Over 50% of this infection and its associated deaths occurred in Sub-Saharan Africa. The West African region is a known hotspot of the HIV-1 epidemic. There is a need to develop an HIV-1 vaccine if the HIV epidemic would be effectively controlled. Few protective cytotoxic T Lymphocytes (CTL) epitopes within the HIV-1 GAG (HIV_gagconsv) have been previously identified to be functionally conserved among the HIV-1 M group. These epitopes are currently the focus of universal HIV-1 T cell-based vaccine studies. However, these epitopes’ phenotypic and genetic properties have not been observed in natural settings for HIV-1 strains circulating in the West African region. This information is critical as the usefulness of universal HIV-1 vaccines in the West African region depends on these epitopes’ occurrence in strains circulating in the area. This study describes non-synonymous substitutions within and without HIV_gagconsv genes isolated from 10 infected Nigerians at the early stages of HIV-1 infection. Furthermore, we analyzed these substitutions longitudinally in five infected individuals from the early stages of infection till after seroconversion. We identified three non-synonymous substitutions within HIV_gagconsv genes isolated from early HIV infected individuals. Fourteen and nineteen mutations outside the HIV_gagconsv were observed before and after seroconversion, respectively, while we found four mutations within the HIV_gagconsv. These substitutions include previously mapped CTL epitope immune escape mutants. CTL immune pressure likely leaves different footprints on HIV-1 GAG epitopes within and outside the HIV_gagconsv. This information is crucial for universal HIV-1 vaccine designs for use in the West African region.

Advances in the creation of animal models of paroxysmal nocturnal hemoglobinuria

ABSTRACT Paroxysmal nocturnal hemoglobinuria (PNH) is a disease caused by a phosphatidylinositol glycan anchor biosynthesis class A (PIG-A) mutation in hematopoietic stem cells. There are three theories about the possible mechanism of the pathogenesis of PNH: immune escape, anti-apoptotic mechanism, and secondary gene mutation. There has been little gain in the knowledge regarding its pathogenesis during the last decade owing to the lack of representative cell lines and animal models. There have been recent reports about the successful creation of PNH mouse and PNH rhesus macaque models. The detection of glycosylphosphatidylinositol-anchor protein (GPI-AP)-deficient cells and/or fluorescently labeled variant of aerolysin (FLAER) test, estimation of erythrocyte life span, and hemolysis-related experiments demonstrated that these animal models of PNH had GPI-AP-deficient blood cells with shortened lifespans and increased sensitivity to complement-activated hemolysis. However, there were no clinical manifestations such as hemolysis and thrombosis in these animal models. This suggested that the PIG-A mutation is one of the several conditions required for PNH, but it alone is not enough to cause PNH.

Recurrent Emergence and Transmission of a SARS-CoV-2 Spike Deletion H69/V70

SARS-CoV-2 Spike amino acid replacements in the receptor binding domain (RBD) occur relatively frequently and some have a consequence for immune recognition. Here we report recurrent emergence and significant onward transmission of a six-nucleotide out of frame deletion in the S gene, which results in loss of two amino acids: H69 and V70. We show that 𝚫H69/V70 and other common NTD deletions occur at loop structures in RNA where polymerase activity is often compromised. In addition, the same two amino acid deletion is also observed in a set of closely related pangolin sarbecoviruses, but not in the bat sarbecovirus RaTG13. We report that in human infections 𝚫H69/V70 often co-occurs with the receptor binding motif amino acid replacements N501Y, N439K and Y453F, and in the latter two cases has followed the RBD mutation suggesting an epistatic interaction. One of the +.-|.-|.-| N501Y lineages, B.1.1.7, has undergone rapid expansion and includes eight other S gene mutations: RBD (N501Y and A570D), S1 (𝚫H69/V70 and 𝚫144/145) and S2 (P681H, T716I, S982A and D1118H). In vitro, we show that 𝚫H69/V70 does not impact serum neutralisation across multiple convalescent sera. However, the 𝚫H69/V70 does increase infectivity of Spike and is able to compensate for infectivity defects induced by RBD mutations N501Y, N439K and Y453F. In addition replacement of H69 and V70 in B.1.1.7 Spike substantially reduces its infectivity. Mechanistically, we demonstrate that 𝚫H69/V70 is associated with two fold increased Spike incorporation into virions, though it does not increase cell-cell fusion. Based on our data 𝚫H69/V70 increases Spike infectivity, likely acting as a permissive mutation that allows acquisition of otherwise deleterious immune escape mutations. Enhanced surveillance for the 𝚫H69/V70 deletion with and without RBD mutations should be considered as a global priority not only as a marker for the B.1.1.7 variant, but potentially also for other emerging variants of concern.Funding Statement: RKG is supported by a Wellcome Trust Senior Fellowship in Clinical Science (WT108082AIA). COG-UK is supported by funding from the Medical Research Council (MRC) & UK&ch & Innovation (UKRI), the National Institute of Health Research (NIHR) and Genome Research Limited, operating as the Wellcome Sanger Institute. SAK is supported by the Bill and Melinda Gates Foundation via PANGEA grant: OPP1175094. DLR is funded by the MRC (MC UU 1201412). WH is funded by the MRC (MR/R024758/1).We thank Dr James Voss for the kind gift of HeLa cells stably expressing ACE2. SL is funded by Medical Research Council MC_UU_12014/12. This study was also partly funded by Rosetrees Trust. Work in the AML lab is supported by NIHR Biomedical Research Centre Grant RCAG 817.Declaration of Interests: RKG has received consulting fees from UMOVIS lab, Gilead Sciences and ViiV Healthcare, and a research grant from InvisiSmart Technologies. On behalf of COG-UK, there are no other interests to declare.Ethics Approval Statement: Ethical approval for use of serum samples. Controls with COVID-19 were enrolled to the NIHR BioResource Centre Cambridge under ethics review board (17/EE/0025).

1066. Immune Escape Mutant Detection Using Commercially Available Methods for Hepatitis B Surface Antigen Serological Testing

BackgroundAlthough overall infection rates of Hepatitis B virus (HBV) in the United States (US) remain stable, as many as 2.2 million persons are still chronically infected with Hepatitis B Virus (HBV)1. Persons who inject drugs (PWID) are at a higher risk of HBV infection and since 2009 three states (KY, TN, WV) have reported up to a 114% increase in cases of acute HBV infection due to higher infection rates among a non-Hispanic white populations (30–39 years), and injection drug users2. Hepatitis B vaccination is recommended as primary prevention for adults who are at increased risk for HBV infection, including PWID. However, data from the National Health Interview Survey indicate that hepatitis B vaccination coverage is low among adults in the general population3, and it is likely to be lower among injection drug users.Hepatitis B Surface Antigen (HBsAg) is the first serological marker to appear after HBV exposure and infection; this marker is included in the recommended panel for acute hepatitis diagnosis and accurate detection is necessary for early and accurate diagnosis. Serological testing challenges exist for HBsAg due to the high degree of genetic variability which can further be exacerbated by endogenous and exogenous pressures. The immuno-dominant region may have one or more mutations described as immune escape mutations which can decrease or abrogate HBsAg binding to antibodies used in immunoassays. Although the prevalence of these mutations is not well documented in the United States, international studies have shown that up to 79% of HBV-reactivated patients (vs 3.1% of control patients; p< 0.001) carry HBsAg mutations localized in immune-active HBsAg regions4.MethodsA study was conducted using a panel of 10 unique recombinant HBsAg immune escape mutants. Panel members were tested by commercially available HBsAg serological immunoassays.ResultsIt was found that although commercially available HBsAg immunoassays are the primary diagnostic tool for HBV diagnosis, not all HBsAg immune escape mutants are detected, with some method detecting as few as 5 out of 10 of these mutant samples.Figure 1 ConclusionImprovement is needed in commercially available methods for the accurate detection of HBsAg.Disclosures Robert Gish, MD, Abbott (Consultant)AbbVie (Consultant, Advisor or Review Panel member, Speaker’s Bureau)Access Biologicals (Consultant)Antios (Consultant)Arrowhead (Consultant)Bayer (Consultant, Speaker’s Bureau)Bristol Myers (Consultant, Speaker’s Bureau)Dova (Consultant, Speaker’s Bureau)Dynavax (Consultant)Eiger (Consultant, Advisor or Review Panel member)Eisai (Consultant, Speaker’s Bureau)Enyo (Consultant)eStudySite (Consultant, Advisor or Review Panel member)Exelixis (Consultant)Fujifilm/Wako (Consultant)Genentech (Consultant)Genlantis (Consultant)Gilead (Consultant, Advisor or Review Panel member, Speaker’s Bureau)GLG (Consultant)HepaTX (Consultant, Advisor or Review Panel member)HepQuant (Consultant, Advisor or Review Panel member)Intercept (Consultant, Speaker’s Bureau)Ionis (Consultant)Janssen (Consultant)Laboratory for Advanced Medicine (Consultant)Lilly (Consultant)Merck (Consultant)Salix (Consultant, Speaker’s Bureau)Shionogi (Consultant, Speaker’s Bureau)Viking (Consultant)