Neuroinvasive Bacillus cereus Infection in Immunocompromised Hosts: Epidemiologic Investigation of 5 Patients With Acute Myeloid Leukemia

Background

Bacillus cereus is a ubiquitous gram-positive rod-shaped bacterium that can cause sepsis and neuroinvasive disease in patients with acute leukemia or neutropenia.

Methods

A single-center retrospective review was conducted to evaluate patients with acute leukemia, positive blood or cerebrospinal fluid test results for B cereus, and abnormal neuroradiographic findings between January 2018 and October 2022. Infection control practices were observed, environmental samples obtained, a dietary case-control study completed, and whole genome sequencing performed on environmental and clinical Bacillus isolates.

Results

Five patients with B cereus neuroinvasive disease were identified. All patients had acute myeloid leukemia (AML), were receiving induction chemotherapy, and were neutropenic. Neurologic involvement included subarachnoid or intraparenchymal hemorrhage or brain abscess. All patients were treated with ciprofloxacin and survived with limited or no neurologic sequelae. B cereus was identified in 7 of 61 environmental samples and 1 of 19 dietary protein samples-these were unrelated to clinical isolates via sequencing. No point source was identified. Ciprofloxacin was added to the empiric antimicrobial regimen for patients with AML and prolonged or recurrent neutropenic fevers; no new cases were identified in the ensuing year.

Conclusions

B cereus is ubiquitous in the hospital environment, at times leading to clusters with unrelated isolates. Fastidious infection control practices addressing a range of possible exposures are warranted, but their efficacy is unknown and they may not be sufficient to prevent all infections. Thus, including B cereus coverage in empiric regimens for patients with AML and persistent neutropenic fever may limit the morbidity of this pathogen.

Comparison of bivalent and monovalent SARS-CoV-2 variant vaccines: the phase 2 randomized open-label COVAIL trial

Vaccine protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection wanes over time, requiring updated boosters. In a phase 2, open-label, randomized clinical trial with sequentially enrolled stages at 22 US sites, we assessed safety and immunogenicity of a second boost with monovalent or bivalent variant vaccines from mRNA and protein-based platforms targeting wild-type, Beta, Delta and Omicron BA.1 spike antigens. The primary outcome was pseudovirus neutralization titers at 50% inhibitory dilution (ID50 titers) with 95% confidence intervals against different SARS-CoV-2 strains. The secondary outcome assessed safety by solicited local and systemic adverse events (AEs), unsolicited AEs, serious AEs and AEs of special interest. Boosting with prototype/wild-type vaccines produced numerically lower ID50 titers than any variant-containing vaccine against all variants. Conversely, boosting with a variant vaccine excluding prototype was not associated with decreased neutralization against D614G. Omicron BA.1 or Beta monovalent vaccines were nearly equivalent to Omicron BA.1 + prototype or Beta + prototype bivalent vaccines for neutralization of Beta, Omicron BA.1 and Omicron BA.4/5, although they were lower for contemporaneous Omicron subvariants. Safety was similar across arms and stages and comparable to previous reports. Our study shows that updated vaccines targeting Beta or Omicron BA.1 provide broadly crossprotective neutralizing antibody responses against diverse SARS-CoV-2 variants without sacrificing immunity to the ancestral strain. ClinicalTrials.gov registration: NCT05289037 .

Immunogenicity of quadrivalent meningococcal conjugate vaccine in frequent platelet donors

Frequent plateletpheresis is associated with severe lymphopenia of uncertain clinical significance. We assessed the functional impact of frequent platelet donations and associated lymphopenia on the response to neoantigens. We conducted a prospective study of 102 platelet donors (HIV uninfected) who were naive to meningococcal vaccination recruited at Brigham and Women's Hospital. One dose of quadrivalent meningococcal conjugate vaccine was administered. Seroresponse was defined as a fourfold increase of serum bactericidal antibody titers and seroprotection was defined as postvaccination titers of ≥1:8, for each of the 4 vaccine antigens (A, C, W, and Y). Mean age of participants was 61 years, 69% were male, and medial number of platelet donations in prior year was 14 (interquartile range, 4-20). Frequent platelet donors had a low CD4 count (14% with ≤200/μL and 34% with ≤350/μL). Seroresponse rates varied from 68% for serogroup Y to 86% for serogroup A and were higher for participants with baseline titers of <1:8. Postvaccination seroprotection rates varied from 76% for serogroup Y to 96% for serogroup A. After adjustments for age, sex, and frequent donations, lower total lymphocyte or lower CD4 counts were not associated with lower responses. These data suggest no impairment by plateletpheresis-associated lymphopenia on response to these neoantigens. This trial was registered at www.clinicaltrials.gov as #NCT04224311.

SARS-CoV-2 Vaccine-Induced Immune Responses Among Hematopoietic Stem Cell Transplant Recipients

Background

Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination reduces the risk and severity of coronavirus disease 2019 (COVID-19), several variables may impact the humoral response among patients undergoing hematopoietic stem cell transplantation (HSCT).

Methods

A retrospective chart review was conducted among SARS-CoV-2-vaccinated HSCT recipients between 2020 and 2022 at a single center in Boston, Massachusetts. Patients age ≥18 years who received doses of Pfizer, Moderna, or J&J vaccines were included. Anti-spike (S) immunoglobulin G (IgG) titer levels were measured using the Roche assay. Responders (≥0.8 U/mL) and nonresponders (<0.8 U/mL) were categorized and analyzed. Multivariable linear and logistic regression were used to estimate the correlation coefficient and odds ratio of response magnitude and status.

Results

Of 152 HSCT recipients, 141 (92.8%) were responders, with a median (interquartile range [IQR]) anti-S IgG titer of 2500 (107.9-2500) U/mL at a median (IQR) of 80.5 (36-153.5) days from last dose, regardless of the number of doses received. Higher quantitative titers were associated with receipt of more vaccine doses (coeff, 205.79; 95% CI, 30.10 to 381.47; P = .022), being female (coeff, 343.5; 95% CI, -682.6 to -4.4; P = .047), being younger (<65 years; coeff, 365.2; 95% CI, -711.3 to 19.1; P = .039), and not being on anti-CD20 therapy (coeff, -1163.7; 95% CI, -1717.7 to -609.7; P = .001). Being male (odds ratio [OR], 0.11; 95% CI, 0.01 to 0.93; P = .04) and being on anti-CD20 therapy (OR, 0.16; 95% CI, 0.03 to 0.70; P = .016) were associated with nonresponse.

Conclusions

Overall, most HSCT recipients had high SARS-CoV-2 antibody responses. More vaccine doses improved the magnitude of immune responses. Anti-S IgG monitoring may be useful for identifying attenuated vaccine-induced responses.

Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine Immunogenicity among Chimeric Antigen Receptor T Cell Therapy Recipients

Patients receiving chimeric antigen receptor T cell (CAR-T) therapy may have impaired humoral responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinations owing to their underlying hematologic malignancy, prior lines of therapy, and CAR-T-associated hypogammaglobulinemia. Comprehensive data on vaccine immunogenicity in this patient population are limited. A single-center retrospective study of adults receiving CD19 or BCMA-directed CAR-T therapy for B cell non-Hodgkin lymphoma or multiple myeloma was conducted. Patients received at least 2 doses of SARS-CoV-2 vaccination with BNT162b2 or mRNA-1273 or 1 dose of Ad26.COV2.S and had SARS-CoV-2 anti-spike antibody (anti-S IgG) levels measured at least 1 month after the last vaccine dose. Patients were excluded if they received SARS-CoV-2 monoclonal antibody therapy or immunoglobulin within 3 months of the index anti-S titer. The seropositivity rate (assessed by an anti-S assay cutoff of ≥.8 U/mL in the Roche assay) and median anti-S IgG titers were analyzed. Fifty patients were included in the study. The median age was 65 years (interquartile range [IQR], 58 to 70 years), and the majority were male (68%). Thirty-two participants (64%) had a positive antibody response, with a median titer of 138.5 U/mL (IQR, 11.61 to 2541 U/mL). Receipt of ≥3 vaccines was associated with a significantly higher anti-S IgG level. Our study supports current guidelines for SARS-CoV-2 vaccination among recipients of CAR-T therapy and demonstrates that a 3-dose primary series followed by a fourth booster increases antibody levels. However, the relatively low magnitude of titers and low percentage of nonresponders demonstrates that further studies are needed to optimize vaccination timing and determine predictors of vaccine response in this population.

Impact of Donor and Recipient SARS-CoV-2 Vaccination or Infection on Immunity after Hematopoietic Cell Transplantation

The role of donor and recipient Coronavirus disease 2019 (COVID-19) immunologic status pre-transplantation has not been fully investigated in allogeneic hematopoietic stem cell transplantation (HSCT) recipients. Given the poor immunogenicity to vaccines in this population and the serious outcomes of COVID-19, adoptive transfer of immunity may offer important insight into improving protection for this vulnerable population. In this study, we evaluated the role of adoptive transfer of immunity at 1 month post-transplantation and 6 months post-transplantation after vaccination of recipients, based on pre-transplantation severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and infection exposures of both recipient and donor. Using banked specimens from related donor allogeneic HSCT recipients and clinical data from both donors and recipients, anti-Spike (S) IgG titers were analyzed at 1, 3, and 6 months post-transplantation according to prior SARS-CoV-2 immunologic exposures. Recipients were excluded if they had received SARS-CoV-2 monoclonal antibodies or had infection in the first 6 months post-transplantation. Of the 53 recipient-donor pairs, 29 donors and 24 recipients had prior SARS-CoV-2 immunologic exposure. Recipient-donor pairs with no prior SARS-CoV-2 exposure (D0R0) had significantly lower anti-S IgG titers at 1 month compared to those with prior exposures (D1R1) (D0R0: median, 2.43 [interquartile range (IQR), .41 to 3.77]; D1R1: median, 8.42; IQR, 5.58 to 12.20]; P = .008). At 6 months, anti-S IgG titers were higher in recipients who were vaccinated at 3 months post-transplantation in the D1R1 cohort (median IgG, 148.34; IQR, 92.36 to 204.33) compared with the D0R0 cohort (median IgG, 38.74; IQR, 8.93 to 119.71). Current strategies should be optimized to enhance SARS-CoV-2 protection for HSCT recipients, including augmentation of the immune response for both donors and recipients prior to transplantation.

Lessons learned: A look back at the performance of nine COVID-19 serologic assays and their proposed utility

BACKGROUND

Serologic assays for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been proposed to assist with the acute diagnosis of infection, support epidemiological studies, identify convalescent plasma donors, and evaluate vaccine response.

METHODS

We report an evaluation of nine serologic assays: Abbott (AB) and Epitope (EP) IgG and IgM, EUROIMMUN (EU) IgG and IgA, Roche anti-N (RN TOT) and anti-S (RS TOT) total antibody, and DiaSorin (DS) IgG. We evaluated 291 negative controls (NEG CTRL), 91 PCR positive (PCR POS) patients (179 samples), 126 convalescent plasma donors (CPD), 27 healthy vaccinated donors (VD), and 20 allogeneic hematopoietic stem cell transplant (HSCT) recipients (45 samples).

RESULTS

We observed good agreement with the method performance claims for specificity (93-100%) in NEG CTRL but only 85% for EU IgA. The sensitivity claims in the first 2 weeks of symptom onset was lower (26-61%) than performance claims based on > 2 weeks since PCR positivity. We observed high sensitivities (94-100%) in CPD except for AB IgM (77%), EP IgM (0%). Significantly higher RS TOT was observed for Moderna vaccine recipients then Pfizer (p-values < 0.0001). A sustained RS TOT response was observed for the five months following vaccination. HSCT recipients demonstrated significantly lower RS TOT than healthy VD (p < 0.0001) at dose 2 and 4 weeks after.

CONCLUSIONS

Our data suggests against the use of anti-SARS-CoV-2 assays to aid in acute diagnosis. RN TOT and RS TOT can readily identify past-resolved infection and vaccine response in the absence of native infection. We provide an estimate of expected antibody response in healthy VD over the time course of vaccination for which to compare antibody responses in immunosuppressed patients.

The mRNA vaccine BNT162b2 demonstrates impaired TH1 immunogenicity in human elders in vitro and aged mice in vivo

mRNA vaccines have been key to addressing the SARS-CoV-2 pandemic but have impaired immunogenicity and durability in vulnerable older populations. We evaluated the mRNA vaccine BNT162b2 in human in vitro whole blood assays with supernatants from adult (18-50 years) and elder (≥60 years) participants measured by mass spectrometry and proximity extension assay proteomics. BNT162b2 induced increased expression of soluble proteins in adult blood (e.g., C1S, PSMC6, CPN1), but demonstrated reduced proteins in elder blood (e.g., TPM4, APOF, APOC2, CPN1, and PI16), including 30-85% lower induction of TH1-polarizing cytokines and chemokines (e.g., IFNγ, and CXCL10). Elder TH1 impairment was validated in mice in vivo and associated with impaired humoral and cellular immunogenicity. Our study demonstrates the utility of a human in vitro platform to model age-specific mRNA vaccine activity, highlights impaired TH1 immunogenicity in older adults, and provides rationale for developing enhanced mRNA vaccines with greater immunogenicity in vulnerable populations.

1939. COVID-19 vaccine immunogenicity among CD19 receptor T-cell (CAR-T) therapy

Background

Patients receiving CAR-T therapy may have impaired humoral responses to SARS-CoV-2 vaccinations due to their high net state of immunosuppression associated with the underlying disease, prior lines of therapy and CAR-T treatment associated hypogammaglobinemia. Comprehensive data on vaccine immunogenicity in this patient population are currently lacking.

Methods

A single-center retrospective study of adults receiving CD19 CAR-T therapy for non-Hodgkin’s lymphoma was conducted between 3/27/2018 – 8/31/2021. Patients received at least two doses of COVID-19 vaccinations with BNT162b2 (Pfizer, BioNTech), mRNA-1273 (Moderna), or 1 dose of Ad26.COV2.S (Janssen) and had SARS-CoV-2 anti-spike (S) levels measured at least one month after the last vaccine dose. We excluded patients who received COVID-19 monoclonal antibody therapy or immunoglobulin within 3 months of the index anti-S titer. Patients were followed from the time of the first COVID-19 vaccines through their index anti-S antibody result. Patients were censored on the first day of any additional antineoplastic therapy after disease relapse. Our primary endpoint was the percentage of patients who develop a positive anti-S response (assessed by anti-S assay cutoff of &gt;0.8 U/mL, Roche assay).

Results

Twenty-five patients met eligibility. Median age was 65 years (range 41 – 78), and majority of patients were male (72%). The number of patients with a positive antibody response was 12 (48%). Median number of vaccines received was 3. 18 patients (72%) received Pfizer vaccines, 4 patients (16%) received Moderna, 2 patients (8%) received Moderna and Pfizer, and 1 patient (4%) received Janssen and Pfizer. Median anti-S titers among patients with a positive response was 111 U/mL (range 2.44 – 12500). Two patients (8%) had COVID-19, both with negative anti-S responses.

Conclusion

Our analysis shows that only 48% of patients who received CAR-T therapy developed a positive antibody response after at least two COVID-19 vaccine doses, with a low median titer among responders. This patient population is at higher risk for developing severe COVID-19 disease and likely remains vulnerable even after vaccination. Alternative approaches are needed to prevent COVID-19 and mitigate disease severity in patients undergoing CAR-T.

Disclosures

Nicolas C. Issa, MD, AiCuris: Grant/Research Support|Merck: Grant/Research Support Sarah P. Hammond, MD, F2G: Advisor/Consultant|F2G: Grant/Research Support|GSK: Grant/Research Support|Scynexis: Grant/Research Support Caron Jacobson, MD, MMSc, Abintus Bio: Advisor/Consultant|Bluebird Bio: Advisor/Consultant|BMS/Celgene: Advisor/Consultant|Daiichi-Sankyo: Advisor/Consultant|Epizyme: Advisor/Consultant|ImmPACT Bio: Advisor/Consultant|Instill Bio: Advisor/Consultant|Ipsen: Advisor/Consultant|Kite/Gilead: Advisor/Consultant|Kite/Gilead: Grant/Research Support|Lonza: Advisor/Consultant|Novartis: Advisor/Consultant|Pfizer: Grant/Research Support.

2098. Cytomegalovirus (CMV) Infection Following Hematopoietic Cell Transplantation (HCT) with Post-transplant Cyclophosphamide (PTCy): Outcomes in Haploidentical versus Matched or Mismatched Unrelated Donor (MUD/MMURD) Allografts

Background

PTCy is increasingly being used in MUD/MMURD, and haploidentical donor HCT for prevention of graft-versus-host disease (GVHD). PTCy has been associated with increased risk of infections including CMV viremia after HCT. It remains unclear if this observation is independent of graft type. This study aims to evaluate the incidence of clinically significant CMV infection (CS-CMVi) following PTCy in MUD/MMURD compared to haploidentical donor HCT.

Methods

We performed a single-center retrospective study of all adults undergoing HCT with PTCy between January 1, 2015 and July 1, 2021. CS-CMVi, defined as CMV viremia or disease requiring initiation of CMV therapy, was evaluated in two groups: haploidentical HCT (n=170) and MUD/MMURD HCT (n=137). We assessed the incidence of CMV viremia, CS-CMVi, and CMV disease, as well as incidence of letermovir breakthrough infections and late CMV events after cessation of prophylaxis. Cumulative Incidence Functions were calculated based on time to CS-CMVi using dates of infection-free death, disease relapse, and repeat HCT as competing risks.

Results

The one-year cumulative incidence of CS-CMVi accounting for competing risks was 25% (95% CI 19 – 32) in the haploidentical group and 18% (95% CI 12 – 25) in the MUD/MMURD group (HR 1.50; 95% CI 0.91 – 2.46; p=0.11). CMV disease was rare, (haploidentical n=1; MUD/MMURD n=1) and no patients died of CMV infection. CS-CMVi in CMV seropositive patients was more common in the haploidentical group (23% versus 9%; p=0.002). Notably, CMV D+/R- HCT patients had a significantly higher rate of CS-CMVi in the MUD/MMURD cohort than in the haploidentical cohort. Of the CS-CMVi, letermovir breakthrough constituted 26% in the haploidentical group and 29% in the MUD/MMURD group. Late infections after cessation of letermovir occurred in only 14% of cases in the haploidentical group and 25% of cases in the MUD/MMURD group.

Conclusion

Rates of CS-CMVi, CMV viremia, and CMV disease were similar following PTCy in haploidentical donor HCT and MUD/MMURD HCT. CS-CMVi in CMV seropositive patients was more common in the haploidentical donor HCT population and MUD/MMURD HCT recipients had a higher incidence of CS-CMVi in the D+/R- patients.

Disclosures

Roman M. Shapiro, M.D., Miltenyi Biotec: Honoraria Rizwan Romee, M.D., Crispr Therapeutics: Grant/Research Support|Glycostem Therapeutics: Advisor/Consultant|NK Therapeutics: Advisor/Consultant|Skyline Therapeutics: Grant/Research Support Robert J. Soiffer, M.D., CSL Behring: Advisor/Consultant|Gilead: Career Chair Development Award|Jasper Therapeutics: Advisor/Consultant|Jazz Pharmaceuticals: Advisor/Consultant|Juno (BMS): DSMB|Kiadis: Board Member|Vor: Advisor/Consultant Vincent T. T. Ho, M.D., Alexion Pharmaceuticals: Advisor/Consultant|Allovir: Advisor/Consultant|Allovir: DSMC|Jazz Pharmaceuticals: Grant/Research Support|Omeros: Advisor/Consultant Nicolas C. Issa, MD, AiCuris: Grant/Research Support|Merck: Grant/Research Support.

1073. SARS-CoV-2 Vaccine-Induced Immunogenicity among Hematopoietic Stem Cell Transplant Recipients (HSCT)

Background

SARS-CoV-2 vaccination reduces the risk and severity of coronavirus disease 2019 (COVID-19), but immunogenicity may be reduced in patients undergoing hematopoietic stem cell transplantation (HSCT). The variables that impact the humoral response, such as age, gender, disease and transplant type, prior treatments, and vaccine type, have not been comprehensively described.

Methods

A retrospective review was conducted at a single-centre of HSCT recipients who received COVID-19 vaccinations between 2020 and 2021. Participants were included if >18 years and had received at least a single dose of Pfizer, Moderna or Johnson & Johnson (J&J) vaccine. Anti-Spike (S) IgG titers were quantitatively measured at provider discretion during routine care using the Roche Elecsys Anti-SARS-CoV-2 spike immunoassay and categorized as Responders (< 0.8U/mL) and Non-responder (>0.8). Multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for Responders vs Non-responders. Controlled risk factors included; Age, disease, treatments, and history of graft-versus-host disease (GVHD).

Results

Of 117 HSCT patients assessed, 59 (50.4%) were female, 106 (90.6%) were white, and the median age was 62.5 years (interquartile range [IQR, 49.9-67.8). Vaccinations were administered at a median of 179 days post-transplant (IQR 319 - 105) and antibody responses were measured at a median of 135.5 days post-vaccination (IQR 190-50). 106(90.6%) were responders with a mean titre of 1141.5U/mL (SD=1095.3). 35% had Low (< 100U/mL) titres. Being Female (OR 0.02, 95%CI 0.003 - 0.6) was associated with a slightly higher odds of being a responder.

Conclusion

Hematopoietic stem cell transplant recipients demonstrated a high prevalence of anti-S IgG antibody positivity following COVID vaccination. However, neither patient characteristics nor treatment regimens were seen to be strongly associated with anti-S protein positivity among HSCT recipients. More studies are needed to further characterize patient and treatment characteristics that correlate with seroprotection among these patients.

Disclosures

Stephen R. Walsh, MD, Janssen Vaccines: Grant/Research Support|ModernaTX: Grant/Research Support|Sanofi Pasteur: Grant/Research Support.

733. Letermovir treatment for refractory or resistant cytomegalovirus infection or disease with concurrent organ dysfunction: an interim analysis of a Phase 2 open label study

Background

Cytomegalovirus (CMV) disease is associated with increased morbidity and mortality following solid organ and hematopoietic cell transplantation. Currently, standard of care CMV treatments often have significant myelosuppressive or renal toxicities. Given letermovir’s favorable safety profile when used prophylactically, it may be a safe and efficacious alternative agent for CMV treatment.

Methods

A proof-of-concept, open-label trial was conducted in patients who lacked effective therapeutic options or presented with baseline organ dysfunction. Participants were eligible for enrollment if they were ≥12 years old and had documented CMV infection refractory to treatment defined as failure to achieve >1 log reduction in CMV viral load (VL) (when VL > 500 IU/mL) or lack of clinical improvement for CMV end-organ disease after ≥14 days of standard CMV treatment. Alternatively, patients with severe myelosuppression and renal dysfunction at baseline or genotypic antiviral resistance were also eligible. Participants were excluded if their current CMV infection developed while receiving letermovir for CMV prophylaxis. Letermovir was administered daily (480 mg PO/IV) for up to 12 weeks, with optional additional 12 weeks of treatment for secondary prophylaxis if clinically indicated.

Results

Ten patients met eligibility criteria and were enrolled. Reasons for enrollment included ganciclovir resistance (1/10), refractory CMV infection (6/10), renal dysfunction (7/10), and myelosuppression (7/10). The median baseline CMV VL was 1272 IU/ml [interquartile range (IQR); 925, 2546]. Six patients completed the study, three died due to complications of primary disease, and one discontinued due to diarrhea. Five patients (50%) had documented CMV viremia clearance, with a median time to first unquantifiable/undetectable CMV VL of 13 days [IQR; 9,18] and a median treatment duration of 53 days [IQR; 15,84]. Infections and GI disorders were the most common adverse events (AE), none considered related to study drug. No unexpected AE were observed during letermovir treatment.

Conclusion

Letermovir may be a safe and tolerable alternative for patients with treatment refractory CMV infection or for patients with severe baseline myelosuppression and renal dysfunction.

Disclosures

Matthew Cheng, MD, AstraZeneca: Honoraria|Cidara Therapeutics: Grant/Research Support|Scynexis Inc.: Grant/Research Support Sandra Burchett, MD, MSc, merck: Grant/Research Support Sarah P. Hammond, MD, F2G: Advisor/Consultant|F2G: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|pfizer: Advisor/Consultant|Scynexis: Grant/Research Support Nicolas C. Issa, MD, AiCuris: Grant/Research Support|Merck: Grant/Research Support Francisco M. Marty, MD, SM, AlloVir: Advisor/Consultant|Amplyx: Advisor/Consultant|Amplyx: Grant/Research Support|Ansun: Grant/Research Support|Avir: Advisor/Consultant|Chimerix: Grant/Research Support|Cidara: Grant/Research Support|F2G: Advisor/Consultant|F2G: Grant/Research Support|Gilead: Grant/Research Support|Janssen: Advisor/Consultant|Kyorin: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Regeneron: Advisor/Consultant|Regeneron: Grant/Research Support|ReViral: Advisor/Consultant|Scynexis: Grant/Research Support|Symbio: Advisor/Consultant|Takeda: Grant/Research Support|United Medical: Advisor/Consultant|WHISCO: Grant/Research Support.

Phenotypes of disease severity in a cohort of hospitalized COVID-19 patients: Results from the IMPACC study

BACKGROUND

Better understanding of the association between characteristics of patients hospitalized with coronavirus disease 2019 (COVID-19) and outcome is needed to further improve upon patient management.

METHODS

Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) is a prospective, observational study of 1164 patients from 20 hospitals across the United States. Disease severity was assessed using a 7-point ordinal scale based on degree of respiratory illness. Patients were prospectively surveyed for 1 year after discharge for post-acute sequalae of COVID-19 (PASC) through quarterly surveys. Demographics, comorbidities, radiographic findings, clinical laboratory values, SARS-CoV-2 PCR and serology were captured over a 28-day period. Multivariable logistic regression was performed.

FINDINGS

The median age was 59 years (interquartile range [IQR] 20); 711 (61%) were men; overall mortality was 14%, and 228 (20%) required invasive mechanical ventilation. Unsupervised clustering of ordinal score over time revealed distinct disease course trajectories. Risk factors associated with prolonged hospitalization or death by day 28 included age ≥ 65 years (odds ratio [OR], 2.01; 95% CI 1.28-3.17), Hispanic ethnicity (OR, 1.71; 95% CI 1.13-2.57), elevated baseline creatinine (OR 2.80; 95% CI 1.63- 4.80) or troponin (OR 1.89; 95% 1.03-3.47), baseline lymphopenia (OR 2.19; 95% CI 1.61-2.97), presence of infiltrate by chest imaging (OR 3.16; 95% CI 1.96-5.10), and high SARS-CoV2 viral load (OR 1.53; 95% CI 1.17-2.00). Fatal cases had the lowest ratio of SARS-CoV-2 antibody to viral load levels compared to other trajectories over time (p=0.001). 589 survivors (51%) completed at least one survey at follow-up with 305 (52%) having at least one symptom consistent with PASC, most commonly dyspnea (56% among symptomatic patients). Female sex was the only associated risk factor for PASC.

INTERPRETATION

Integration of PCR cycle threshold, and antibody values with demographics, comorbidities, and laboratory/radiographic findings identified risk factors for 28-day outcome severity, though only female sex was associated with PASC. Longitudinal clinical phenotyping offers important insights, and provides a framework for immunophenotyping for acute and long COVID-19.

FUNDING

NIH.

Severe Acute Respiratory Syndrome Coronavirus 2 Messenger RNA Vaccines in Allogeneic Hematopoietic Stem Cell Transplant Recipients: Immunogenicity and Reactogenicity

The severe acute respiratory syndrome coronavirus 2 messenger RNA vaccine-induced humoral response and reactogenicity profile are described in allogeneic hematopoietic stem cell transplant (HSCT) recipients. Findings showed that 75.0% (by Simoa assay) or 80.0% (by Roche assay) of the HSCT cohort had a positive antibody response on series completion, compared with 100% in the healthy cohort.

Immunogenicity of a three-dose primary series of mRNA COVID-19 vaccines in patients with lymphoid malignancies

Background

Patients with lymphoid malignancies are at risk for poor COVID-19 related outcomes and have reduced vaccine-induced immune responses. Currently a three-dose primary regimen of mRNA vaccines is recommended in the U.S. for immunocompromised hosts.

Methods

A prospective cohort study of healthy adults (n = 27) and patients with lymphoid malignancies (n = 94) was conducted, with longitudinal follow-up through completion of a two or three-dose primary mRNA COVID vaccine series, respectively. Humoral responses were assessed in all participants, and cellular immunity in a subset of participants.

Results

The rate of seroconversion (68.1% v. 100%) and the magnitude of peak anti-S IgG titer (median anti-S IgG 32.4, IQR 0.48-75.0 v. 72.6, IQR 51.1-100.1; p = 0.0202) were both significantly lower in patients with lymphoid malignancies as compared to the healthy cohort. However, peak titers of patients with lymphoid malignancies who responded to vaccination were similar to healthy cohort titers (median anti-S IgG 64.3, IQR 23.7 - 161.5, p = 0.7424). The third dose seroconverted 7/41 (17.1%) patients who were seronegative after the first two doses. Although most patients with lymphoid malignancies produced vaccine-induced T-cell responses in the subset studied, B-cell frequencies were low with minimal memory cell formation.

Conclusions

A three-dose primary mRNA series enhanced anti-S IgG responses to titers equivalent to healthy adults in patients with lymphoid malignancies who were seropositive after the first two doses and seroconverted 17.1% who were seronegative after the first two doses. T-cell responses were present, raising the possibility that the vaccines may confer some cell-based protection even if not measurable by anti-S IgG.

SARS-CoV-2 Variant Vaccine Boosters Trial: Preliminary Analyses

Background

Protection from SARS-CoV-2 vaccines wanes over time and is compounded by emerging variants including Omicron subvariants. This study evaluated safety and immunogenicity of SARS-CoV-2 variant vaccines.

Methods

This phase 2 open-label, randomized trial enrolled healthy adults previously vaccinated with a SARS-CoV-2 primary series and a single boost. Eligible participants were randomized to one of six Moderna COVID19 mRNA vaccine arms (50µg dose): Prototype (mRNA-1273), Omicron BA.1+Beta (1 or 2 doses), Omicron BA.1+Delta, Omicron BA.1 monovalent, and Omicron BA.1+Prototype. Neutralization antibody titers (ID 50 ) were assessed for D614G, Delta, Beta and Omicron BA.1 variants and Omicron BA.2.12.1 and BA.4/BA.5 subvariants 15 days after vaccination.

Results

From March 30 to May 6, 2022, 597 participants were randomized and vaccinated. Median age was 53 years, and 20% had a prior SARS-CoV-2 infection. All vaccines were safe and well-tolerated. Day 15 geometric mean titers (GMT) against D614G were similar across arms and ages, and higher with prior infection. For uninfected participants, Day 15 Omicron BA.1 GMTs were similar across Omicron-containing vaccine arms (3724-4561) and higher than Prototype (1,997 [95%CI:1,482-2,692]). The Omicron BA.1 monovalent and Omicron BA.1+Prototype vaccines induced a geometric mean ratio (GMR) to Prototype for Omicron BA.1 of 2.03 (97.5%CI:1.37-3.00) and 1.56 (97.5%CI:1.06-2.31), respectively. A subset of samples from uninfected participants in four arms were also tested in a different laboratory at Day 15 for neutralizing antibody titers to D614G and Omicron subvariants BA.1, BA.2.12.2 and BA.4/BA.5. Omicron BA.4/BA.5 GMTs were approximately one third BA.1 GMTs (Prototype 517 [95%CI:324-826] vs. 1503 [95%CI:949-2381]; Omicron BA.1+Beta 628 [95%CI:367-1,074] vs. 2125 [95%CI:1139-3965]; Omicron BA.1+Delta 765 [95%CI:443-1,322] vs. 2242 [95%CI:1218-4128] and Omicron BA.1+Prototype 635 [95%CI:447-903] vs. 1972 [95%CI:1337-2907).

Conclusions

Higher Omicron BA.1 titers were observed with Omicron-containing vaccines compared to Prototype vaccine and titers against Omicron BA.4/BA.5 were lower than against BA.1 for all candidate vaccines.

Clinicaltrialsgov

NCT05289037.

Pediatric Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Vaccines: Perceptions and Attitudes From the Food and Drug Administration Public Commentary

Authorization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines for children has ushered in a new phase of the immunization campaign to address the pandemic but has been received with mixed responses from parents, children, and opinion leaders. Herein we consider perceptions and attitudes towards pediatric SARS-CoV-2 vaccines from a Food and Drug Administration (FDA) public commentary reflecting more than 63 000 comments.

The Effect of Vaccine Type and SARS-CoV-2 Lineage on Commercial SARS-CoV-2 Serologic and Pseudotype Neutralization Assays in mRNA Vaccine Recipients

The use of anti-spike (S) serologic assays as surrogate measurements of SARS-CoV-2 vaccine induced immunity will be an important clinical and epidemiological tool. The characteristics of a commercially available anti-S antibody assay (Roche Elecsys anti-SARS-CoV-2 S) were evaluated in a cohort of vaccine recipients. Levels were correlated with pseudotype neutralizing antibodies (NAb) across SARS-CoV-2 variants. We recruited adults receiving a two-dose series of mRNA-1273 or BNT162b2 and collected serum at scheduled intervals up to 8 months post-first vaccination. Anti-S and NAb levels were measured, and correlation was evaluated by (i) vaccine type and (ii) SARS-CoV-2 variant (wild-type, Alpha, Beta, Gamma, and three constructs Day 146*, Day 152*, and RBM-2). Forty-six mRNA vaccine recipients were enrolled. mRNA-1273 vaccine recipients had higher peak anti-S and NAb levels compared with BNT162b2 (P < 0.001 for anti-S levels; P < 0.05 for NAb levels). When anti-S and NAb levels were compared, there was good correlation (all r values ≥ 0.85) in both BNT162b2 and mRNA-1273 vaccine recipients across all evaluated variants; however, these correlations were nonlinear in nature. Lower correlation was identified between anti-S and NAb for the Beta variant (r = 0.88) compared with the wild-type (WT) strain (r = 0.94). Finally, the degree of neutralizing activity at any given anti-S level was lower for each variant compared with that of the WT strain, (P < 0.001). Although the Roche anti-S assay correlates well with NAb levels, this association is affected by vaccine type and SARS-CoV-2 variant. These variables must be considered when interpreting anti-S levels. IMPORTANCE We evaluated anti-spike antibody concentrations in healthy mRNA vaccinated individuals and compared these concentrations to values obtained from pseudotype neutralization assays targeting SARS-CoV-2 variants of concern to determine how well anti-spike antibodies correlate with neutralizing titers, which have been used as a marker of immunity from COVID-19 infection. We found high peak anti-spike concentrations in these individuals, with significantly higher levels seen in mRNA-1273 vaccine recipients. When we compared anti-spike and pseudotype neuralization titers, we identified good correlation; however, this correlation was affected by both vaccine type and variant, illustrating the difficulty of applying a "one size fits all" approach to anti-spike result interpretation. Our results support CDC recommendations to discourage anti-spike antibody testing to assess for immunity after vaccination and cautions providers in their interpretations of these results as a surrogate of protection in COVID-vaccinated individuals.

Coronavirus Disease 2019 Vaccine Trials (and Tribulations): How to Improve the Process of Clinical Trials in a Pandemic

Vaccine clinical trials have been essential to developing effective severe acute respiratory syndrome coronavirus 2 vaccines. The challenges of supply chain disruptions, infection control, study designs, and participant factors that affect trial procedures are reviewed, with specific solutions to streamline the clinical trial process.

Vaccine-Induced Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Response and the Path to Accelerating Development (Determining a Correlate of Protection)

As new public health challenges relating to COVID-19 emerge, such as variant strains, waning vaccine efficacy over time, and decreased vaccine efficacy for special populations (immunocompromised hosts), it is important to determine a correlate of protection (CoP) to allow accurate bridging studies for special populations and against variants of concern. Large-scale phase 3 clinical trials are inefficient to rapidly assess novel vaccine candidates for variant strains or special populations, because these trials are slow and costly. Defining a practical CoP will aid in efficiently conducting future assessments to further describe protection for individuals and on a population level for surveillance.

An aluminum hydroxide:CpG adjuvant enhances protection elicited by a SARS-CoV-2 receptor binding domain vaccine in aged mice

Global deployment of vaccines that can provide protection across several age groups is still urgently needed to end the COVID-19 pandemic, especially in low- and middle-income countries. Although vaccines against SARS-CoV-2 based on mRNA and adenoviral vector technologies have been rapidly developed, additional practical and scalable SARS-CoV-2 vaccines are required to meet global demand. Protein subunit vaccines formulated with appropriate adjuvants represent an approach to address this urgent need. The receptor binding domain (RBD) is a key target of SARS-CoV-2 neutralizing antibodies but is poorly immunogenic. We therefore compared pattern recognition receptor (PRR) agonists alone or formulated with aluminum hydroxide (AH) and benchmarked them against AS01B and AS03-like emulsion-based adjuvants for their potential to enhance RBD immunogenicity in young and aged mice. We found that an AH and CpG adjuvant formulation (AH:CpG) produced an 80-fold increase in anti-RBD neutralizing antibody titers in both age groups relative to AH alone and protected aged mice from the SARS-CoV-2 challenge. The AH:CpG-adjuvanted RBD vaccine elicited neutralizing antibodies against both wild-type SARS-CoV-2 and the B.1.351 (beta) variant at serum concentrations comparable to those induced by the licensed Pfizer-BioNTech BNT162b2 mRNA vaccine. AH:CpG induced similar cytokine and chemokine gene enrichment patterns in the draining lymph nodes of both young adult and aged mice and enhanced cytokine and chemokine production in human mononuclear cells of younger and older adults. These data support further development of AH:CpG-adjuvanted RBD as an affordable vaccine that may be effective across multiple age groups.

Structural basis for continued antibody evasion by the SARS-CoV-2 receptor binding domain

Many studies have examined the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants on neutralizing antibody activity after they have become dominant strains. Here, we evaluate the consequences of further viral evolution. We demonstrate mechanisms through which the SARS-CoV-2 receptor binding domain (RBD) can tolerate large numbers of simultaneous antibody escape mutations and show that pseudotypes containing up to seven mutations, as opposed to the one to three found in previously studied variants of concern, are more resistant to neutralization by therapeutic antibodies and serum from vaccine recipients. We identify an antibody that binds the RBD core to neutralize pseudotypes for all tested variants but show that the RBD can acquire an N-linked glycan to escape neutralization. Our findings portend continued emergence of escape variants as SARS-CoV-2 adapts to humans.

Safety of Live-Attenuated Measles, Mumps, and Rubella Vaccine Administered Within 2 Years of Hematopoietic Cell Transplant

Background

Measles, mumps, and rubella (MMR) vaccine is a live-attenuated vaccine usually contraindicated within the first 2 years of hematopoietic cell transplant (HCT). The objective of this study was to assess the safety of MMR vaccine when administered within 2 years of HCT.

Methods

We conducted a retrospective review of patients who received MMR vaccination within 2 years of an autologous or allogeneic HCT, mostly in the context of the 2019 measles outbreak. Adverse reactions were collected for 42 days postvaccination, and all hospitalizations and deaths following vaccination were reviewed.

Results

A total of 129 patients (75 autologous and 54 allogeneic HCT) were vaccinated 300–729 days after HCT (median, 718 days), and 39 (30%) of these were vaccinated earlier than 23 months post-transplant. Ten adverse reactions in 7 patients (5%) were identified within 42 days of vaccination: 6 respiratory tract infections (3 with fever) and 1 rash. The rash was seen in a 37-year-old female who had an allogeneic HCT 542 days before vaccination. She presented with a centrifugal maculopapular rash, confirmed to be caused by the vaccine strain rubella virus. She fully recovered. No other vaccine-associated illness was identified in the cohort after a median follow-up of 676 days.

Conclusions

MMR vaccine appears to be well tolerated in select HCT recipients when given between 300 and 729 days after transplant. An uncomplicated case of vaccine-associated rubella illness was seen after vaccination. Assessment of potential risks and benefits of MMR vaccination given within 2 years of HCT remains important.

100. Safety Analysis of Live-Attenuated Measles, Mumps, Rubella Vaccine Among Hematopoietic Cell Transplant Recipients Vaccinated Within Two Years of Transplant

Background

Measles, mumps and rubella (MMR) vaccine is a live-attenuated vaccine usually contraindicated within the first two years of hematopoietic cell transplant (HCT). During the 2019 measles outbreak at our center, the benefits of administering MMR vaccine within the first two years after HCT were weighed against the potential risks.

Methods

We conducted a retrospective review of patients who received MMR vaccination within two years of an autologous or allogeneic HCT. Patients’ demographics, date and type of HCT, underlying hematologic disease, type of immunosuppressive therapy and date of MMR vaccination were extracted from the electronic medical record. Adverse reactions that could be related to the vaccine were collected for up to 42 days post-vaccination and all hospitalizations and deaths following vaccination were reviewed.

Results

A total of 129 patients (75 autologous and 54 allogeneic HCT) were vaccinated between 300-729 days after HCT (median of 718 days). The median age at vaccination was 61 years old, 57% of the patients were male and 43% were on immunosuppressive therapy, 87% of whom were on maintenance therapy for multiple myeloma after auto-HCT. Seven patients (5%) had adverse reactions within 42 days of vaccination: six had respiratory tract infections (three with associated fever) and one had a rash leading to a brief hospitalization. This was a 37-year-old female who had an allogeneic HCT 542 days prior to MMR vaccination. She presented with a centrifugal maculopapular rash that was confirmed to be caused by the vaccine strain rubella virus (Fig 1). She fully recovered without sequalae. There was no other vaccine-associated illness identified in the cohort, after a median follow-up of 676 days.

Conclusion

MMR vaccine appears to be well tolerated in selected HCT recipients when given earlier than 2 years after transplant. No attributable severe outcomes or deaths were described. A mild uncomplicated case of vaccine-associated rubella illness was seen after vaccination. In the setting of a measles outbreak, assessment of potential risks and benefits of MMR vaccination given within two years of HCT remains important.

Disclosures

Stephen R. Walsh, MDCM, Janssen Vaccines (Scientific Research Study Investigator)Regeneron (Scientific Research Study Investigator)Sanofi Pasteur (Scientific Research Study Investigator) Matthew Cheng, MD, GEn1E Lifesciences (Advisor or Review Panel member)Kanvas Biosciences (Board Member, Shareholder)nplex biosciences (Advisor or Review Panel member) Sanjat Kanjilal, MD, MPH, GlaskoSmithKline (Advisor or Review Panel member) Nicolas C. Issa, MD, AiCuris (Scientific Research Study Investigator)Astellas (Scientific Research Study Investigator)GSK (Scientific Research Study Investigator)Merck (Scientific Research Study Investigator)

25. Immunogenicity and Reactogenicity of COVID-19 mRNA Vaccines in Allogeneic Stem Cell Transplant Recipients

Background

Allogeneic stem cell transplant (SCT) recipients are at an increased risk of poor outcomes from COVID-19. While the mRNA-1273 (Moderna) and BNT162b2 (Pfizer) COVID-19 mRNA vaccines are highly immunogenic in the general population, the immune response in SCT recipients is poorly understood. We characterized the immunogenicity and reactogenicity of COVID-19 mRNA vaccines in a cohort of SCT patients.

Methods

We performed a prospective cohort study of 16 allogeneic SCT patients and 23 healthy controls. Blood samples for both cohorts were collected prior to first vaccination (baseline), at the time of second vaccination, and approximately 28 days post-second vaccination. Anti-Spike (S), anti-S1, anti-receptor binding domain (RBD), and anti-Nucleocapsid (N) IgG levels were measured quantitatively from plasma using a multiplexed single molecule array (Simoa) immunoassay. Reactogenicity was captured for the SCT cohort via a self-reported post-vaccination diary for 7 days after each dose.

Results

Demographics and SCT recipients’ characteristics are shown in Table 1. In the SCT cohort, we observed a significantly lower anti-S (p< 0.0001), S1 (p< 0.0001), and RBD (p< 0.0001) IgG responses as compared to healthy controls, both at the time of dose 2 and 28 days post-vaccine series (Fig 1). Overall, 62.5% of SCT recipients were responders after vaccine series completion, as compared to 100% of healthy controls (Fig 2). While no patients had a reported history of COVID-19 diagnosis, 2 patients in the SCT cohort had elevated anti-S IgG levels and 1 showed elevated anti-N at baseline.

10/16 participants in the SCT cohort completed at least one post-vaccination diary. Local and systemic reactions were reported by 67% and 22% of participants, respectively, after dose 1, and 63% and 50% after dose 2 (Figure 3). All reported events were mild.

Table 1: Demographics

Figure 1: Plasma IgG Titers

Anti-Spike (A), anti-S1 (B), anti-RBD (C), and anti-nucleocapsid (D) IgG titers were measured at baseline, time of second dose, and approximately 28 days after second vaccination. IgG levels were measured quantitatively using multiplexed single molecule array (Simoa) immunoassays, and are reported as Normalized Average Enzymes per Bead (AEB). Allogeneic stem cell transplant recipients (mauve) showed significantly lower anti-S, S1, and RBD IgG responses as compared to healthy controls (mint). Low titers of anti-N IgG demonstrates no history of COVID-19 natural infection during the course of the study.

Figure 3. Solicited Local and Systemic Adverse Events

10 allogeneic stem cell transplant recipients completed at least one diary for 7 days after vaccination. Reactions after dose 1 are shown in light blue, and reactions after dose 2 are shown in dark blue. Local reactions (A) were reported by 67% (6/9) of participants after dose 1, and 63% (5/8) after dose 2. Systemic reactions (B) were reported by 22% (2/9) of participants after dose 1, and 50% (4/8) after dose 2. All reported events were mild (Grade 1).

Conclusion

Among SCT recipients, mRNA COVID-19 vaccines were well-tolerated but less immunogenic than in healthy controls. Further study is warranted to better understand heterogeneous characteristics that may affect the immune response in order to optimize COVID-19 vaccination strategies for SCT recipients.

Figure 2: Response Rate to COVID-19 Vaccination

An internally validated threshold for responders was established using pre-pandemic sera from healthy adults. A positive antibody response was was defined as individuals with anti-Spike IgG levels above the 1.07 Normalized AEB threshold.

Disclosures

Amy Joyce, NP, Kadmon (Advisor or Review Panel member) Lewis A. Novack, MS, Lumicell Inc. (Scientific Research Study Investigator, Research Grant or Support)Precision Healing, Inc. (Scientific Research Study Investigator, Research Grant or Support) David Walt, PhD, Quanterix Corporation (Board Member, Shareholder) Robert Soiffer, MD, alexion (Consultant)gilead (Advisor or Review Panel member)jazz (Advisor or Review Panel member)juno/bms (Advisor or Review Panel member)kiadis (Board Member)precision bioscience (Consultant)Rheos (Consultant)takeda (Consultant) Nicolas C. Issa, MD, AiCuris (Scientific Research Study Investigator)Astellas (Scientific Research Study Investigator)GSK (Scientific Research Study Investigator)Merck (Scientific Research Study Investigator)

586. Immunogenicity of COVID-19 mRNA Vaccines in Patients with Lymphoid Malignancies

Background

Patients with lymphoid malignancies are at high risk of severe COVID-19 disease and were not included in the phase 3 mRNA vaccine trials. Many patients with lymphoid malignancies receive immunosuppressive therapies, including B-cell depleting agents, that may negatively impact humoral response to vaccination.

Methods

We recruited patients with lymphoid malignancies and healthy participants who planned to receive two doses of SARS-CoV-2 mRNA vaccine (BNT162b2 or mRNA-1273). Blood was drawn at baseline, prior to second dose of vaccine, and 28 days after last vaccination. Disease characteristics and therapies were extracted from patients’ electronic medical record. An ultrasensitive, single molecule array (Simoa) assay detected anti-Spike (S), anti-S1, anti-receptor binding domain (RBD), and anti-Nucleocapsid (N) IgG from plasma at each timepoint.

Results

23 healthy participants and 37 patients with lymphoid malignancies were enrolled (Table 1). Low titers of anti-N (Fig 1A) demonstrate no prior exposure or acquisition of COVID-19 before vaccination or during the study. 37.8% of the lymphoid malignancy cohort responded to the vaccine, using an internally validated AEB cutoff of 1.07. A significantly higher magnitude of anti-S (p< 0.0001), anti-S1 (p< 0.0001) and anti-RBD (p< 0.0001) are present in the healthy as compared to lymphoid malignancy cohort at the second dose and day 28 post-series (Fig 1B, Fig 1C and Fig 1D). Anti-S IgG titers were compared between the healthy cohort, treatment naïve, and treatment experienced groups (Fig 2). The treatment naïve cohort had high titers by series completion which were not significantly different from the healthy cohort (p=0.2259), although the treatment experienced group had significantly decreased titers (p< 0.0001). Of the 20 patients who had received CD20 therapy, there was no clear correlation of anti-S IgG response with time from CD20 therapy, although most patients who received CD20 therapies within 12 months from the vaccine had no response (Figure 3).

Table 1. Demographics

Figure 1. Anti-N, Anti-S, Anti-S1, Anti-RBD and Anti-N Ig G for healthy v. lymphoid malignancy cohort

The dotted line at 1.07 marks in an internally validated threshold to mark anti-S IgG response. The black bars denote median with 95% CI.

Figure 2: Anti-S IgG for healthy v. treatment naïve v. treatment experienced

The dotted line at 1.07 marks in an internally validated threshold to mark antibody response. The black bars denote median with 95% CI.

Conclusion

The vaccine-induced immune response was poor among treatment-experienced patients with lymphoid malignancies, especially among those who received CD20 therapies within 12 months.

Figure 3. Months from CD20 therapy v. anti-S IgG titers

The dotted line at 1.07 marks in an internally validated threshold to mark antibody response.

Disclosures

Jennifer Crombie, MD, AbbVie (Grant/Research Support)Bauer (Grant/Research Support)Karyopharm (Consultant)MorphoSys (Consultant) Philippe Armand, MD PhD, ADCT, Celgene, Morphosys, Daiichi, Miltenyi, Tessa, C4, Genmab, Enterome, Regeneron, Genentech, Epizyme, Astra Zeneca (Consultant, Sorry to put them all in, hope you can deconvolute for me)Affimed, Adaptive, BMS, Merck, Kite, IGM, Genentech (Research Grant or Support, Institutional research funding) David Walt, PhD, Quanterix Corporation (Board Member, Shareholder) Nicolas C. Issa, MD, AiCuris (Scientific Research Study Investigator)Astellas (Scientific Research Study Investigator)GSK (Scientific Research Study Investigator)Merck (Scientific Research Study Investigator)

996. CD4+ T-Cell Lymphopenia Associated with Frequent Plateletpheresis in Healthy Donors

Background

Frequent plateletpheresis using the Time Accel leukoreduction system chamber may result in lymphopenia in healthy donors, with increased donation in the previous year associated with CD4+ T-cell count of less than 200 cells/µL. However, this finding has not been replicated and the clinical significance of plateletpheresis-associated lymphopenia remains unclear.

Methods

A prospective observational study of healthy plateletpheresis donors aged 18 or older who donated at least once in the previous 365 days was conducted at the Kraft Blood Center at Brigham and Women’s Hospital/Dana Farber Cancer Institute, where the Time Accel system is used exclusively. Blood was drawn immediately before plateletpheresis or at least 2 weeks after the last donation to assess for total lymphocyte and CD4+ T-cell counts.

Results

A total of 86 participants were enrolled: 23 had 1-5 donations, 36 had 6-19 donations, and 27 had 20-24 donations within the previous 365 days (Figure 1). For the low-, medium-, and high-frequency donation groups, the median age was 53 years (IQR 43-64), 61 years (IQR 53-68), and 61 years (IQR 55-65), respectively. The median total lymphocyte count was 1.5 (IQR 1.3-1.9), 1.2 (IQR 0.9-1.5), 0.8 (IQR 0.6-0.9) 10³ cells/µL, and the median CD4+ T-cell count was 648 (IQR 531-843), 525 (IQR 348-698), and 220 (IQR 184-347) cells/µL. CD4+ T-cell counts were < 200 cells/µL in 0/23 (0%), 3/36 (8%), and 9/27 (33%) participants across the three groups. Total lymphocyte and CD4+ T-cell counts were inversely correlated with the number of platelet donations in the prior 365 days, R² = 0.384 (Fig 2) and 0.402 (Fig 3) respectively.

Conclusion

Frequent plateletpheresis using Time Accel leukoreduction system chamber is associated with CD4+ T-cell lymphopenia, with counts below 200 cells/µL seen in one third of those who donated 20-24 times in the previous year. Vaccine immunogenicity studies are ongoing to evaluate the clinical significance of this finding.

Disclosures

Stephen R. Walsh, MDCM, Janssen Vaccines (Scientific Research Study Investigator)Regeneron (Scientific Research Study Investigator)Sanofi Pasteur (Scientific Research Study Investigator)

Application of SARS-CoV-2 Serology to Address Public Health Priorities

Background: Antibodies against SARS-CoV-2 can be detected by various testing platforms, but a detailed understanding of assay performance is critical. Methods: We developed and validated a simple enzyme-linked immunosorbent assay (ELISA) to detect IgG binding to the receptor-binding domain (RBD) of SARS-CoV-2, which was then applied for surveillance. ELISA results were compared to a set of complimentary serologic assays using a large panel of clinical research samples. Results: The RBD ELISA exhibited robust performance in ROC curve analysis (AUC> 0.99; Se = 89%, Sp = 99.3%). Antibodies were detected in 23/353 (6.5%) healthcare workers, 6/9 RT-PCR-confirmed mild COVID-19 cases, and 0/30 non-COVID-19 cases from an ambulatory site. RBD ELISA showed a positive correlation with neutralizing activity (p = <0.0001, R2 = 0.26). Conclusions: We applied a validated SARS-CoV-2-specific IgG ELISA in multiple contexts and performed orthogonal testing on samples. This study demonstrates the utility of a simple serologic assay for detecting prior SARS-CoV-2 infection, particularly as a tool for efficiently testing large numbers of samples as in population surveillance. Our work also highlights that precise understanding of SARS-CoV-2 infection and immunity at the individual level, particularly with wide availability of vaccination, may be improved by orthogonal testing and/or more complex assays such as multiplex bead assays.

SARS-CoV-2 mRNA Vaccine Attitudes as Expressed in U.S. FDA Public Commentary: Need for a Public-Private Partnership in a Learning Immunization System

As part of the U.S. Food and Drug Administration COVID-19 vaccine review process, public commentary was solicited offering an opportunity to reflect on vaccine attitudes that may impact the uptake of coronavirus vaccines. We identified themes in the commentary that highlighted the safety, efficacy, ethics, and trustworthiness and transparency regarding the novel mRNA COVID-19 vaccines. A “Learning Immunization System” model is proposed to optimize public, private, and academic partnerships relating to vaccine development and implementation.

Systems Biological Analysis of Immune Response to Influenza Vaccination

The last decade has witnessed tremendous progress in immunology and vaccinology, owing to several scientific and technological breakthroughs. Systems vaccinology is a field that has emerged at the forefront of vaccine research and development and provides a unique way to probe immune responses to vaccination in humans. The goals of systems vaccinology are to use systems-based approaches to define signatures that can be used to predict vaccine immunogenicity and efficacy and to delineate the molecular mechanisms driving protective immunity. The application of systems biological approaches in influenza vaccination studies has enabled the discovery of early signatures that predict immunogenicity to vaccination and yielded novel mechanistic insights about vaccine-induced immunity. Here we review the contributions of systems vaccinology to influenza vaccine development and critically examine the potential of systems vaccinology toward enabling the development of a universal influenza vaccine that provides robust and durable immunity against diverse influenza viruses.

Alum:CpG adjuvant enables SARS-CoV-2 RBD-induced protection in aged mice and synergistic activation of human elder type 1 immunity

Global deployment of vaccines that can provide protection across several age groups is still urgently needed to end the COVID-19 pandemic especially for low- and middle-income countries. While vaccines against SARS-CoV-2 based on mRNA and adenoviral-vector technologies have been rapidly developed, additional practical and scalable SARS-CoV-2 vaccines are needed to meet global demand. In this context, protein subunit vaccines formulated with appropriate adjuvants represent a promising approach to address this urgent need. Receptor-binding domain (RBD) is a key target of neutralizing antibodies (Abs) but is poorly immunogenic. We therefore compared pattern recognition receptor (PRR) agonists, including those activating STING, TLR3, TLR4 and TLR9, alone or formulated with aluminum hydroxide (AH), and benchmarked them to AS01B and AS03-like emulsion-based adjuvants for their potential to enhance RBD immunogenicity in young and aged mice. We found that the AH and CpG adjuvant formulation (AH:CpG) demonstrated the highest enhancement of anti-RBD neutralizing Ab titers in both age groups (∼80-fold over AH), and protected aged mice from the SARS-CoV-2 challenge. Notably, AH:CpG-adjuvanted RBD vaccine elicited neutralizing Abs against both wild-type SARS-CoV-2 and B.1.351 variant at serum concentrations comparable to those induced by the authorized mRNA BNT162b2 vaccine. AH:CpG induced similar cytokine and chemokine gene enrichment patterns in the draining lymph nodes of both young adult and aged mice and synergistically enhanced cytokine and chemokine production in human young adult and elderly mononuclear cells. These data support further development of AH:CpG-adjuvanted RBD as an affordable vaccine that may be effective across multiple age groups.

One Sentence Summary

Alum and CpG enhance SARS-CoV-2 RBD protective immunity, variant neutralization in aged mice and Th1-polarizing cytokine production by human elder leukocytes.

Circulating SARS-CoV-2 Vaccine Antigen Detected in the Plasma of mRNA-1273 Vaccine Recipients

SARS-CoV-2 proteins were measured in longitudinal plasma samples collected from 13 participants who received two doses of mRNA-1273 vaccine. 11 of 13 participants showed detectable levels of SARS-CoV-2 protein as early as day one after first vaccine injection. Clearance of detectable SARS-CoV-2 protein correlated with production of IgG and IgA.

The Effect of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Mitigation Strategies on Seasonal Respiratory Viruses: A Tale of 2 Large Metropolitan Centers in the United States

To assess the impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic on seasonal respiratory viruses, absolute case counts and viral reproductive rates from 2019-2020 were compared against previous seasons. Our findings suggest that the public health measures implemented to reduce SARS-CoV-2 transmission significantly reduced the transmission of other respiratory viruses.

Human Adenovirus 11 in 2 Renal Transplant Recipients: Suspected Donor-Derived Infection

BACKGROUND

Human adenovirus (HAdV) infections can lead to high mortality in solid organ transplant (SOT) recipients, with rare reports of donor-derived infection.

METHODS

Two renal transplant recipients with HAdV-11 infection who received kidneys from the same donor are described. Whole-genome sequencing (WGS) was performed.

RESULTS

WGS showed 100% nucleotide sequence identity for the 2 HAdV-11 isolates. The patients presented with distinct clinical syndromes, and both were treated with brincidofovir.

CONCLUSIONS

Donor-derived HAdV infection is presumed to be low; however, disseminated HAdV in SOT recipients can be severe, and clinicians should be aware of the clinical course and treatment options.

506. Variation in Occupational Activities and Infection Prevention Practices in Healthcare Personnel Based on Exposure to COVID-19 Units

Background

Healthcare personnel (HCP) may be at increased risk for COVID-19, but differences in risk by work activities are poorly defined. Centers for Disease Control and Prevention recommends cohorting hospitalized patients with COVID-19 to reduce in-hospital transmission of SARS-CoV-2, but it is unknown if occupational and non-occupational behaviors differ based on exposure to COVID-19 units.

Methods

We analyzed a subset of HCP from an ongoing CDC-funded SARS-CoV-2 serosurveillance study. HCP were recruited from four Atlanta hospitals of different sizes and patient populations. All HCP completed a baseline REDCap survey. We used logistic regression to compare occupational activities and infection prevention practices among HCP stratified by exposure to COVID-19 units: low (0% of shifts), medium (1–49% of shifts) or high (≥50% of shifts).

Results

Of 211 HCP enrolled (36% emergency department [ED] providers, 35% inpatient RNs, 17% inpatient MDs/APPs, 7% radiology technicians and 6% respiratory therapists [RTs]), the majority (79%) were female and the median age was 35 years. Nearly half of the inpatient MD/APPs (46%) and RNs (47%) and over two-thirds of the RTs (67%) worked primarily in the ICU. Aerosol generating procedures were common among RNs, MD/APPs, and RTs (26–58% performed ≥1), but rare among ED providers (0–13% performed ≥1). Compared to HCP with low exposure to COVID-19 units, those with medium or high exposure spent a similar proportion of shifts directly at the bedside and were about as likely to practice universal masking. Being able to consistently social distance from co-workers was rare (33%); HCP with high exposure to COVID-19 units were less likely to report social distancing in the workplace compared to those with low exposure; however, this was not significantly different (OR 0.6; 95% CI: 0.3, 1.1). Concerns about personal protective equipment in COVID-19 units were similar across levels of exposure (Table 1).

Table 1: Occupational activities and infection prevention behaviors of healthcare personnel stratified by level of exposure to COVID-19 units

Conclusion

The proportion of time spent in dedicated COVID-19 units did not appear to influence time HCP spend directly at the bedside or infection prevention practices (social distancing and universal masking) in the workplace. Risk for SARS-CoV-2 infection in HCP may depend more on factors acting at the individual level rather than those related to location of work.

Disclosures

Jessica Howard-Anderson, MD, Antibacterial Resistance Leadership Group (ARLG) (Other Financial or Material Support, The ARLG fellowship provides salary support for ID fellowship and mentored research training) Ben Lopman, PhD, MSc, Takeda Pharmaceuticals (Advisor or Review Panel member, Research Grant or Support, Other Financial or Material Support, Personal fees)World Health Organization (Advisor or Review Panel member, Other Financial or Material Support, Personal fees for technical advice and analysis)

484. The Impact of SARS-CoV-2 on Reproduction Rates of Seasonal Influenza and RSV

Background

The COVID-19 pandemic caused by SARS-CoV-2 has precipitated a global health crisis. In an effort to decrease person-to-person transmission, societal-level non-pharmacologic interventions (NPIs) to maintain social distancing have been enacted. As SARS-CoV-2 shares similar routes of transmission with other respiratory viruses, implementation of these NPIs may have decreased transmission for multiple viral pathogens. We compared influenza and respiratory syncytial (RSV) rates in prior seasons to rates during the 2019 - 2020 season at two large academic centers in Atlanta and Boston.

Methods

The clinical records were queried for adults with respiratory virus testing conducted at the Emory Healthcare system and associated clinics in Atlanta and the Mass General Brigham (MGB) Healthcare System in Boston. Total cases for influenza A and B, RSV and SARS-CoV-2 were analyzed for each week of the past 5 seasons (07/01/2015-05/30/2020) for the Atlanta and Boston sites. Systematic changes in viral infection rates were calculated using viral reproduction rates, R(t), between consecutive weeks. R(t) is the ratio of the number of positive cases in one week to the number of positive cases in the previous week. We used statistical bootstrapping to determine whether R(t) for influenza and RSV were lower in 2019–2020 following the introduction of SARS-CoV-2. Analyses were conducted using R (v 4.0.0).

Absolute respiratory virus activity by season, Boston (panel A) v. Atlanta (panel B)

Results

For the 2019–2020 Atlanta season, R(t) < 1 (which reflects steady decline in infection rates) occurred at week 28 for influenza A, week 33 for influenza B, and week 35 for RSV, which corresponded with the increase of SARS-Cov-2 cases. The R(t) of these viruses stayed at or near 1 during weeks 33–35 in prior seasons, and R(t) was greater than 1 up to week 47. Data from MGB sites showed similar trends with a sudden decline in R(t) to < 1 at the start of the SARS-CoV-2 pandemic.

Conclusion

We note decreased transmission of influenza and RSV during a time window where widespread movement restrictions and social distancing were imposed to control COVID-19. This trend was most pronounced for influenza A in Atlanta and influenza B in Boston. These data suggest that NPIs can have important effects across multiple pathogens.

Disclosures

Kraft Colleen, MD, MSc, Rebiotix (Advisor or Review Panel member)

1112. #EducationInTheTimeofCOVID: Using Twitter to Disseminate Evidence-Based Medicine during a Pandemic

Background

The medical community has used Twitter as a learning tool during the COVID-19 pandemic to digest the high volume of rapidly evolving literature. However, Twitter contains educational content of varying quality and accuracy. To address this issue, we created and disseminated visual abstracts of COVID-19 literature on Twitter to educate health professionals.

Methods

Fellows and faculty members from multiple institutions collaborated with Emory University medical students to create visual abstracts of published COVID-19 literature (Figure 1). ID fellows and faculty identified and summarized 10-15 high-impact COVID-19 articles each week. Medical students created visual abstracts for each article, which fellows or faculty reviewed for accuracy. We disseminated them on Twitter (@JenniferSpicer4, 4,373 followers) and our website (Figure 2). We measured engagement with tweets using Twitter Analytics.

Figure 1: COVID-19 Visual Abstract Example

Figure 2: Website hosting COVID-19 weekly literature summaries and visual abstracts (https://med.emory.edu/departments/medicine/divisions/infectious-diseases/covid19-roundup/)

Results

Since March 2020, we have created, reviewed, and disseminated 139 graphics with 116 student authors and 33 fellow/faculty reviewers across three academic institutions (Table 1). Topics included public health & prevention, virology & basic science, epidemiology, transmission & infection control, clinical syndrome, diagnostics, therapeutics, vaccinology, and ethics & policy. Tweets had a median of 9,300 impressions (interquartile range [IQR] 5,432-13,233) with 766 engagements (IQR 432-1,288) and an engagement rate of 8.6% (IQR 7.1%-10.0%) (Table 2). Each tweet had a median of 25 retweets (IQR 17-38) and 55 likes (IQR 34-81). A few tweets had significantly higher metrics; maximum values were 84,257 impressions, 9,758 engagements, 19.0% engagement rate, 239 retweets, and 381 likes. In addition to disseminating graphics on Twitter, we received requests to use them as teaching aids from multiple health professionals worldwide, and the visual abstracts have been translated into Spanish and disseminated on Twitter and Instagram via @MEdSinFrontera.

Table 1: Descriptive Statistics of COVID-19 Visual Series

Table 2: Twitter Metrics for COVID-19 Visual Series (as of 6/10/2020)

Conclusion

Engagement rates with our visual abstracts were high, demonstrating the power of Twitter. ID educators can use visual abstracts to summarize and disseminate accurate information to a large audience on social media, which is especially important in the setting of an emerging infection.

Disclosures

All Authors: No reported disclosures

411. Application of a SARS-CoV-2-specific serologic assay for translational research and surveillance

Background

Sensitive and specific SARS-CoV-2 antibody diagnostics are urgently needed to estimate the seroprevalence of SARS-CoV-2 infection in both the general population and special risk groups. Moreover, validated serologic assays are critical to understanding immunity to SARS-CoV-2 infection over time and identifying correlates of protection.

Methods

An enzyme-linked immunosorbent assay (ELISA) protocol to detect antibodies (IgG) that bind the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein was validated and ROC curve analysis performed by testing a large panel of pre-pandemic sera (n=162) and convalescent sera from RT-PCR-confirmed COVID-19 cases (n=60). We then applied this test in two cohorts: 1) Healthcare personnel (HCP) that were enrolled in a longitudinal surveillance cohort just after peak local transmission and 2) Mildly ill patients being tested for SARS-CoV-2 infection by RT-PCR from NP swabs in an ambulatory testing clinic.

Demographics of mildly symptomatic patients tested for SARS-CoV-2 with RT-PCR

Results

ROC curve analysis yielded an AUC of 0.9953, with a sensitivity and specificity at 91.67% and 99.38% at the optimal OD normalization threshold of 0.20. In 240 HCP surveilled at enrollment, 5.83% had positive IgG results. Of 19 symptomatic patients who presented to the ambulatory clinic, 5/19 had a positive PCR. In convalescence (13–74 days post symptom onset), 3 of those 5 were positive for IgG.

Validation of the SARS-CoV-2 RBD ELISA

Conclusion

We demonstrated high sensitivity and specificity of the SARS-CoV-2 RBD ELISA. This simple assay is an efficient way to track seroconversion and duration of antibody responses to SARS-CoV-2 for different populations, particularly since RBD-binding antibodies have been shown to correlate with neutralization activity and may be useful to determine protective immunity following natural infection or vaccination. Ongoing work will assess variation in magnitude, character and duration of antibody responses in key populations and seek to maximize deployability of large-scale SARS-CoV-2 serology.

Disclosures

Jessica Howard-Anderson, MD, MSc, Antibacterial Resistance Leadership Group (ARLG) (Other Financial or Material Support, The ARLG fellowship provides salary support for ID fellowship and mentored research training) Nadine Rouphael, MD, Lilly (Grant/Research Support)Merck (Grant/Research Support)Pfizer (Grant/Research Support)Quidel (Grant/Research Support)Sanofi Pasteur (Grant/Research Support)

442. Common symptoms of outpatient COVID-19 compared to non-COVID-19 Cases: A prospective epidemiologic study in a major US metropolitan area

Background

The majority of novel coronavirus 2019 (COVID-19) cases is comprised of non-critically ill adults. However, the medical epidemiology and clinical profile for mild COVID-19 is poorly described in the United States.

Methods

We prospectively recruited 151 mildly symptomatic adults from Emory Healthcare COVID-19 screening clinics in Atlanta, Georgia from March 18 to June 16, 2020. Interview-based questionnaires captured participants’ demographics, epidemiological history, and clinical features. Nasopharyngeal swabs were collected to test for SARS-CoV-2 by RT-PCR. Convalescent serum (13–74 days post symptom onset) from 19 participants was tested by an IgG ELISA. Descriptive and χ ² analyses were performed to determine the characteristics of COVID-19 cases compared to patients who tested negative.

Results

A total of 151 patients were recruited. The majority were non-Hispanic white (51%), female (60%), middle-aged adults (46.3 y +/-15). Twenty-seven (17.9%) tested positive for SARS-CoV-2 and most frequently reported fever (63%), cough (67%), fatigue (56%), and myalgias (56%). See Table 1. Fever was statistically more common in positive cases vs negative (63% vs 34%, p = 0.005). Cases also experienced loss of taste (22%) and loss of smell (19%) more frequently than non-cases (p=0.01 and p=0.03). Diarrhea (22% vs 23%) and shortness of breath (33% vs 36%) did not differ significantly between groups. None of the 14 PCR-negative participants tested positive for SARS-CoV-2-specific IgG and 3 out of 5 COVID-19 cases tested positive for SARs-CoV-2-specific IgG.

Conclusion

Mild COVID-19 cases reported fever, loss of smell and loss of taste significantly more than non-COVID-19 cases. Strong correlations between anosmia and ageusia with COVID-19 have been reported elsewhere, however these symptoms were only present in 19–22% of cases at the time of testing, limiting their utility for clinical diagnosis. Also, none of the PCR-negative participants tested positive for convalescent serology, supporting good sensitivity and negative predictive value of the RT-PCR test used in our clinic. Symptoms alone cannot differentiate COVID-19 from other illnesses, highlighting the critical need for widely available and highly sensitive and specific diagnostic tests.

Disclosures

All Authors: No reported disclosures

COVID-19 Serology at Population Scale: SARS-CoV-2-Specific Antibody Responses in Saliva

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of an ongoing pandemic that has infected over 36 million and killed over 1 million people. Informed implementation of government public health policies depends on accurate data on SARS-CoV-2 immunity at a population scale. We hypothesized that detection of SARS-CoV-2 salivary antibodies could serve as a noninvasive alternative to serological testing for monitoring of SARS-CoV-2 infection and seropositivity at a population scale. We developed a multiplex SARS-CoV-2 antibody immunoassay based on Luminex technology that comprised 12 CoV antigens, mostly derived from SARS-CoV-2 nucleocapsid (N) and spike (S). Saliva and sera collected from confirmed coronavirus disease 2019 (COVID-19) cases and from the pre-COVID-19 era were tested for IgG, IgA, and IgM to the antigen panel. Matched saliva and serum IgG responses (n = 28) were significantly correlated. The salivary anti-N IgG response resulted in the highest sensitivity (100%), exhibiting a positive response in 24/24 reverse transcription-PCR (RT-PCR)-confirmed COVID-19 cases sampled at >14 days post-symptom onset (DPSO), whereas the salivary anti-receptor binding domain (RBD) IgG response yielded 100% specificity. Temporal kinetics of IgG in saliva were consistent with those observed in blood and indicated that most individuals seroconvert at around 10 DPSO. Algorithms employing a combination of the IgG responses to N and S antigens result in high diagnostic accuracy (100%) by as early as 10 DPSO. These results support the use of saliva-based antibody testing as a noninvasive and scalable alternative to blood-based antibody testing.

COVID-19 serology at population scale: SARS-CoV-2-specific antibody responses in saliva

Non-invasive SARS-CoV-2 antibody testing is urgently needed to estimate the incidence and prevalence of SARS-CoV-2 infection at the general population level. Precise knowledge of population immunity could allow government bodies to make informed decisions about how and when to relax stay-at-home directives and to reopen the economy. We hypothesized that salivary antibodies to SARS-CoV-2 could serve as a non-invasive alternative to serological testing for widespread monitoring of SARS-CoV-2 infection throughout the population. We developed a multiplex SARS-CoV-2 antibody immunoassay based on Luminex technology and tested 167 saliva and 324 serum samples, including 134 and 118 negative saliva and serum samples, respectively, collected before the COVID-19 pandemic, and 33 saliva and 206 serum samples from participants with RT-PCR-confirmed SARS-CoV-2 infection. We evaluated the correlation of results obtained in saliva vs. serum and determined the sensitivity and specificity for each diagnostic media, stratified by antibody isotype, for detection of SARS-CoV-2 infection based on COVID-19 case designation for all specimens. Matched serum and saliva SARS-CoV-2 antigen-specific IgG responses were significantly correlated. Within the 10-plex SARS-CoV-2 panel, the salivary anti-nucleocapsid (N) protein IgG response resulted in the highest sensitivity for detecting prior SARS-CoV-2 infection (100% sensitivity at ≥10 days post-SARS-CoV-2 symptom onset). The salivary anti-receptor binding domain (RBD) IgG response resulted in 100% specificity. Among individuals with SARS-CoV-2 infection confirmed with RT-PCR, the temporal kinetics of IgG, IgA, and IgM in saliva were consistent with those observed in serum. SARS-CoV-2 appears to trigger a humoral immune response resulting in the almost simultaneous rise of IgG, IgM and IgA levels both in serum and in saliva, mirroring responses consistent with the stimulation of existing, cross-reactive B cells. SARS-CoV-2 antibody testing in saliva can play a critically important role in large-scale "sero"-surveillance to address key public health priorities and guide policy and decision-making for COVID-19.

Serogroup A meningococcal conjugate vaccines: building sustainable and equitable vaccine strategies

INTRODUCTION

For well over 100 years, meningococcal disease due to serogroup A Neisseria meningitidis (MenA) has caused severe epidemics globally, especially in the meningitis belt of sub-Saharan Africa.

AREAS COVERED

The article reviews the background and identification of MenA, the global and molecular epidemiology of MenA, and the outbreaks of MenA in the African meningitis belt. The implementation (2010) of an equitable MenA polysaccharide-protein conjugate vaccine (PsA-TT, MenAfriVac) and the strategy to control MenA in sub-Saharan Africa is described. The development of a novel multi-serogroup meningococcal conjugate vaccine (NmCV-5) that includes serogroup A is highlighted. The PubMed database (1996-2019) was searched for studies relating to MenA outbreaks, vaccine, and immunization strategies; and the Neisseria PubMLST database of 1755 MenA isolates (1915-2019) was reviewed.

EXPERT OPINION

Using strategies from the successful MenAfriVac campaign, expanded collaborative partnerships were built to develop a novel, low-cost multivalent component meningococcal vaccine that includes MenA. This vaccine promises greater sustainability and is directed toward global control of meningococcal disease in the African meningitidis belt and beyond. The new WHO global roadmap addresses the continuing problem of bacterial meningitis, including meningococcal vaccine prevention, and provides a framework for further reducing the devastation of MenA.

2739. Comparison of Hemagglutination Antibody Inhibition (HAI) Titers Following Influenza Vaccination by Birth Cohort and Repeated Influenza Vaccination History

Background

The host immune response to influenza vaccination can be affected by prior imprinting to a specific influenza strain based on birth cohort and prior influenza vaccination history. Understanding the underlying immune mechanisms is essential to development of an improved seasonal vaccine and an effective universal influenza vaccine.

Methods

This is a prospective pilot study, with a total of 20 subjects in either the H3N2 cohort (N = 10, born 1968–1977) or the H1N1 cohort (N = 10, born 1948–1957). Each cohort was further stratified by subjects who have received the influenza vaccine < 2 or ≥ 3 of the past 5 years. The FDA-approved quadrivalent 2018–19 influenza vaccine (containing A(H1N1), an A/Michigan/45/2015-like virus; A(H3N2), an A/Singapore/INFIMH-16–0019/2016-like virus; B/Colorado/06/2017-like virus; and B/Phuket/3073/2013-like virus) was administered on Day 1. Demographic information included age, gender, ethnicity, and BMI. HAI titers for each component of the vaccine were obtained at baseline, 29 days post-vaccination, and 180 days post-vaccination. HAI fold-change and HAI geometric mean titers (GMT) were analyzed.

Results

There was no significant difference between H1N1 or H3N2 HAI fold-change in the H3N2 birth cohort (P = 0.7496) or in the H1N1 birth cohort (P = 0.8237), Figure A. Comparing HAI fold-change for the repeatedly vs. minimally vaccinated groups, there was a significant higher fold change in the minimally vaccinated group (H1N1 HAI (P = 0.002) and H3N2 HAI (P < 0.0001), Figure B). GMT was higher at baseline for the repeatedly vaccinated group (H1N1, 70; H3N2, 98; vs. H1N1, 30; H3N2, 21 for the minimally vaccinated group); however, the GMT for the minimally vaccinated group was higher at day 29 (H1N1, 172; H3N2, 184; vs. H1N1, 422; H3N2, 299 for the minimally vaccinated group; Figure C). HAI titers and analysis at day 180 post vaccination are in progress.

Conclusion

There was no evidence of an imprinting effect by birth cohort for HAI titer magnitudes, even when stratified by vaccination history. There was a significantly higher HAI fold change for individuals who had received minimal influenza vaccinations in the past 5 years at 29 days post-vaccination. Individuals who had repeated vaccinations in the last 5 years had higher HAI GMT at baseline.

Disclosures

Nadine Rouphael, MD, Merck: I conduct as Emory PI the PNEUMO MERCK study at Emory, Research Grant; Pfizer: I conduct as co-PI the RSV PFIZER study at Emory, Research Grant; Sanofi-Pasteur: I conducted as Emory PI the CDIFFENSE trial at Emory, Research Grant.

Extrahepatic manifestations of hepatitis C infection: navigating CHASM

This article describes the importance of extrahepatic systemic manifestations of chronic hepatitis C virus (HCV) infection. While most HCV literature focuses on liver injury and fibrosis progression, a spectrum of systemic disease processes, collectively called C hepatitis-associated systemic manifestations (CHASMs), are present in a high proportion of infected persons. These include thyroid disease (Hashimoto's thyroiditis, Graves disease, and thyroid cancer), cardiovascular disease (atherosclerosis, carotid artery disease, and coronary artery disease), renal disease (MPGN and glomerulosclerosis), eye disease (Mooren's ulcers and sicca syndrome), skin disease (PCT, vasculitis, and lichen planus), lymphomas (NHL and splenic T-cell), and diabetes. Mechanistic understanding of how HCV leads to CHASM processes could lead to development of new interventions. The role of early HCV treatment and cure may result in preventive strategies for a variety of complex disease states. Key Points • Systemic extrahepatic complications of HCV comprise a spectrum of disease states in many organs and systems.• Effective treatment of HCV may reduce or eliminate some but not all of these systemic complications.• Further research into early treatment intervention as a prevention strategy for systemic disease is warranted.

Augmentation of hepatitis B virus-specific cellular immunity with programmed death receptor-1/programmed death receptor-L1 blockade in hepatitis B virus and HIV/hepatitis B virus coinfected patients treated with adefovir

The immunological parameters leading to viral persistence in chronic hepatitis B (CHB) are not clearly established. We analyzed HBV-specific immunoregulatory mechanisms in HIV-infected and HIV-uninfected HBeAg(+) CHB patients to determine (1) the roles of immunoregulatory pathways, (2) the effect of anti-HBV therapy on immunoregulatory pathways, and (3) the role of immunomodulatory therapy to overcome the effect of T regulatory cells (Tregs, CD4(+)CD25(+)FoxP3(+)) in HBV-infected individuals. A prospective, double blind, randomized, placebo-controlled trial treated HBV (HIV(+/-))-infected patients with adefovir 10 mg daily or placebo for 48 weeks. HBV viral load (VL), immunophenotying, and functional studies were performed at multiple time points. Suppression of HBV VL with adefovir leads to decreased peripheral expansion of Tregs. While declining, Tregs significantly inhibit cytokine-secreting HBV-specific CD8(+) T cell responses over 48 weeks of anti-HBV adefovir therapy (p<0.05). A large proportion of these Tregs express programmed death receptor-1 (PD-1), blockade of which in vitro leads to improved cytokine-secreting HBV-specific CD8(+) T cell responses, particularly in HIV/HBV-coinfected patients (p<0.05). Peripheral expansion of Treg levels correlated with HBV viral load and decreased HBV-specific CD8(+) T cells. PD-1 blockade increased survival of HBV-specific CD8(+) T cells, removing the inhibitory effect of PD-1(+) peripheral Tregs. Hence therapies involving PD-1 blockade in combination with directly acting antivirals should be investigated to reduce the need for life-long directly acting antiviral therapy.

Psychosocial supportive care for children receiving stem cell transplantation: practice patterns across centers

Although pediatric stem cell transplantation is associated with elevated risks for quality-of-life (QOL) deficits, morbidity, and late effects, little is known about how supportive care needs are addressed across different pediatric centers. This study examined practice patterns among centers enrolled in the Pediatric Blood and Marrow Transplant Consortium. In all, 65 centers (response rate=82.2%) were surveyed regarding QOL screening, psychosocial intervention services, and long-term follow-up care. Approximately 80% of centers provided routine screening for psychological difficulties and pain. A smaller number screened for fatigue (69.2%), cognitive deficits (52.3%), sleep difficulties (60.0%) or spiritual concerns (38.5%). Screening was conducted predominantly via interview; little use was made of standardized measures. Community-based centers screened some deficits more frequently than did academic ones (all P's</=0.09). In all, 60% of centers provided support groups and 49.2% offered arts-in-medicine programs. Most centers provided extended follow-up care. In some, follow-up continued until age 21 (45.4%), while in others it was sustained indefinitely (40.6%). Findings suggest that QOL screening would be enhanced by greater attention to domains that currently receive limited scrutiny, and by increased use of validated measures to supplement interview information. The proportion of centers that provide extended follow-up is encouraging, and offers opportunities to study long-term outcomes.

Psychosocial adjustment and quality of life among multiple myeloma patients undergoing evaluation for autologous stem cell transplantation

Stem cell transplantation has assumed a prominent place in the treatment of multiple myeloma, but relative to patients with other malignancies there is surprisingly little information about the adjustment difficulties and quality-of-life changes that these patients experience. This study examined psychosocial and functional deficits among myeloma patients assessed at a uniform period during their initial diagnostic evaluation, prior to beginning protocols at a transplant center. Validated self-report measures and clinician rating scales were used to assess 213 patients. Outcomes evaluated included emotional distress (Hospital Anxiety and Depression Scale, Brief Symptom Inventory), depression (Hamilton Depression Rating Scale), physical functioning, pain, and energy (SF-12). A significant proportion of patients experienced compromised psychosocial and physical functioning. Roughly one-third reported clinically elevated levels of distress, anxiety, and depression. In all, 59% scored below age-adjusted norms for daily physical functioning, 58% reported at least moderate levels of pain, and over 80% noted at least moderate fatigue. Clinical and demographic correlates of these outcomes were examined. These findings are among the first to characterize quality-of-life outcomes among myeloma patients in the transplant setting, and indicate that many patients experience considerable supportive care needs even prior to beginning aggressive regimens. Results highlight the importance of early screening.

Measuring religious faith in cancer patients: reliability and construct validity of the Santa Clara Strength of Religious Faith questionnaire

Growing attention has focused on associations between religious involvement and health outcomes for cancer patients. Unfortunately, research has been hampered by lack of measures suitable for use in oncology settings. This study examined the performance of one recently developed measure, the Santa Clara Strength of Religious Faith Questionnaire (SCSORF). Initial investigations with cancer patients in a bone marrow transplant program and with non-oncology patients yielded promising results. This study provided additional information about temporal stability and convergent validity. The measure was evaluated in two well-defined samples: (1) 95 breast cancer patients, and (2) 53 healthy young adults. Most of the cancer patients had recent diagnoses and localized or regional disease. In each sample, the instrument demonstrated high test-retest reliability (r's=0.82-0.93) and internal consistency (r's=0.95-0.97). It displayed strong correlations with measures of intrinsic religiosity (r's=0.67-0.82, p<0.0001), and moderate correlations with organizational religiosity (r's=0.61-069, p<0.0001), non-organizational religiosity (r's=0.52-0.55, p<0.0001), comfort from religion (r=0.58, p<0.0001), and ratings of self as religious (r=0.58, p<0.0001). Among cancer patients, scores were significantly associated with optimism (r=0.30, p<0.01), but not with openness of family communication about cancer or perceived social support. These data build on previous findings with cancer patients, and suggest that the SCSORF may be a useful measure of religious faith in oncology settings.