Covid-19 Vaccinated Maternal/Cord Blood Dont Have Neutralization for Omicron Variants

Background: Maternally derived antibodies are crucial for neonatal immunity. Understanding the binding and -cross neutralization capacity of maternal/ cord antibody responses to COVID-19 vaccination during pregnancy can inform neonatal immunity. Method(s): Here we characterized binding and neutralizing antibody profile at delivery in 24 pregnant individuals following two doses of Moderna mRNA-1273 or Pfizer BNT162b2 vaccination. We evaluated the transplacental antibody transfer by profiling maternal and umbilical cord blood. We analyzed for SARS-CoV-2 multivariant cross-neutralizing antibody levels for wildtype Wuhan, Delta, Omicron BA1, BA2, and BA4/BA5 variants by enzyme-linked immunosorbent assay Results: Our results reveal that current vaccination induced significantly higher (p=0.003) RBD-specific binding IgG titers in cord blood compared to maternal blood for both Wuhan and Omicron BA1 strain. Interestingly, binding IgG antibody levels for the Omicron BA1 strain were significantly lower (P< 0.0001) when compared to the Wuhan strain in both maternal and cord blood. In contrast to the binding, the Omicron BA1, BA2, BA4/5 specific neutralizing antibody levels were significantly lower (P< 0.0001) compared to the Wuhan and Delta variants. It is interesting to note that the BA4/5 neutralizing capacity was not at all detected in both maternal and cord blood. Conclusion(s): Our data suggest that the initial series of COVID-19 mRNA vaccines were immunogenic in pregnant women, and vaccine-elicited binding antibodies were detectable in cord blood at significantly higher levels for Wuhan and Delta variants but not for Omicron variants. Interestingly, the vaccination did not induce neutralizing antibodies for Omicron variants. These results provide novel insight into the impact of vaccination on maternal humoral immune response and transplacental antibody transfer for SARS-CoV-2 variants and support the need for boosters as new variants emerge.

PATIENTS WITH ASTHMA OR ATOPIC DERMATITIS TAKING BIOLOGIC THERAPIES HAVE REDUCED SARS-COV-2 VACCINE RESPONSE AT SIX MONTHS

SESSION TITLE: Late Breaking Insights In Management of Asthma and COPD SESSION TYPE: Original Investigations PRESENTED ON: 10/18/2022 09:15 am - 10:15 am PURPOSE: SARS-CoV-2 vaccines have greatly reduced the impact of the COVID-19 pandemic. However, immune responses and their ability to protect against SARS-CoV-2 infection and severe clinical outcomes vary amongst vaccinees. Understanding who remains at high risk for severe infection despite vaccination and who may need additional vaccine boosters is critical for the control of this and future pandemics. We recently reported a reduced humoral immune response after mRNA SARS-CoV-2 vaccination in patients with severe asthma or atopic dermatitis on biologic therapies three months after the second vaccination, compared to healthy controls. The purpose of this study is to characterize the immune response of these patients six months after vaccination. METHODS: We conducted a prospective observational trial from February 2021 to February 2022 and enrolled 77 adults with severe asthma or atopic dermatitis treated with benralizumab, mepolizumab or dupilumab, receiving a SARS-CoV-2 mRNA vaccination, in addition to 45 healthy controls. We analyzed pseudovirus neutralization against wild-type, Delta variant and Omicron variant SARS-CoV-2, using a pseudotyped lentivirus. RESULTS: After excluding patients with prior COVID-19 or significant immunosuppression, we analyzed 28 patients (5 patients on benralizumab, 20 patients on dupilumab, 3 patients on mepolizumab) in addition to 34 healthy controls at 6 months after vaccination. We found that patients with severe asthma or atopic dermatitis treated with biologics had lower pseudovirus neutralization titer at 6 months, compared to healthy controls. The mean 50% inhibitory dilution against wild-type SARS-CoV-2 among patients on biologics were lower at 2.313 log10 compared to 2.743 log10 in the healthy control group, p-value <0.0001. Additionally, the patients on biologics had lower neutralizing antibody titers against Delta variant and Omicron variant SARS-CoV-2. CONCLUSIONS: Our data shows that patients with severe asthma or atopic dermatitis on biologic therapies have lower neutralization titer after SARS-CoV-2 mRNA vaccination compared to healthy controls 6 months after the second vaccination. Large population studies have recently shown that severe or active asthma is associated with worse COVID-19 outcomes and several studies have shown that lower humoral immunity after vaccination is associated with less protection against disease. It is therefore critical to provide booster vaccinations to these vulnerable patients. CLINICAL IMPLICATIONS: Clinicians should encourage patients with severe asthma or atopic dermatitis on biologic therapies to receive SARS-CoV-2 booster vaccinations as they may unknowingly remain at high risk for severe disease. DISCLOSURES: No relevant relationships by Fabliha Anam No relevant relationships by Suneethamma Cheedarla No relevant relationships by Narayanaiah Cheedarla No relevant relationships by John Daiss No relevant relationships by Natalie Haddad No relevant relationships by Ian Hentenaar No relevant relationships by Fernando Holguin No relevant relationships by Caroline Kim No relevant relationships by Pedro Lamothe No relevant relationships by Frances Lee No relevant relationships by ANDREW NEISH No relevant relationships by wendy neveu No relevant relationships by Rahulkumar Patel No relevant relationships by Carmen Polito No relevant relationships by Richard Ramonell No relevant relationships by Mayuran Ravindran No relevant relationships by John Roback No relevant relationships by Martin Runnstrom Consultant relationship with BLI, Inc. Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=Royalty Consultant relationship with Bristol Meyers Squibb/Celgene Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=Consulting fee Speaker/Speaker's Bureau relationship with Bristol Meyers Squibb/Celgene Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=H noraria Consultant relationship with GlaxoSmithKline Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=Consulting fee Speaker/Speaker's Bureau relationship with GlaxoSmithKline Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=Honoraria Consultant relationship with Janssen Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=Consulting fee Speaker/Speaker's Bureau relationship with Janssen Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=Honoraria Consultant relationship with Visterra Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=Consulting fee Speaker/Speaker's Bureau relationship with Visterra Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=Honoraria Consultant relationship with Kyverna Please note: past 36 months Added 07/18/2022 by Ignacio Sanz, value=Consulting fee No relevant relationships by Sunita Sharma No relevant relationships by Colin Swenson No relevant relationships by Robert Swerlick

Estimating SARS-CoV-2 Seroprevalence from Spent Blood Samples, January-March 2021

Background. Measuring SARS-CoV-2 antibody prevalence in spent samples at serial time points can determine seropositivity in a diverse pool of individuals to inform understanding of trends as vaccinations are implemented. Methods. Blood samples collected for clinical testing and then discarded ("spent samples") were obtained from the clinical laboratory of a medical center in Atlanta. A convenience sample of spent samples from both inpatients (medical/surgical floors, intensive care, obstetrics) and outpatients (clinics and ambulatory surgery) were collected one day per week from January-March 2021. Samples were matched to clinical data from the electronic medical record. In-house single dilution serological assays for SARSCoV-2 receptor binding domain (RBD) and nucleocapsid (N) antibodies were developed and validated using pre-pandemic and PCR-confirmed COVID-19 patient serum and plasma samples (Figure 1). ELISA optical density (OD) cutoffs for seroconversion were chosen using receiver operating characteristic analysis with areas under the curve for all four assays greater than 0.95 after 14 days post symptom onset. IgG profiles were defined as natural infection (RBD and N positive) or vaccinated (RBD positive, N negative). Single dilution serological assays for SARS-CoV-2 nucleocapsid antibodies were validated using pre-pandemic and PCR-confirmed COVID-19 patient serum and plasma samples. ELISA optical density (OD) cutoffs for seroconversion were chosen using receiver operating characteristic (ROC) analysis with areas under the curve (AUC) for all four assays greater than 0.95 after 14 days post symptom onset. Results. A total of 2406 samples were collected from 2132 unique patients. Median age was 58 years (IQR 40-70), with 766 (36%) ≥ 65 years. The majority were female (1173, 55%), and 1341 (63%) were Black. Median Elixhauser comorbidity index was 5 (IQR 2-9). 210 (9.9%) patients ever had SARS-CoV-2 detected by PCR, and 191 (9.0%) received a COVID-19 vaccine within the health system. Nearly half (1186/2406, 49.3%) of samples were collected from inpatient units, 586 (24.4%) from outpatient labs, 403 (16.8%) from the emergency department, and 231 (9.6%) from infusion centers. Overall, 17.0% had the IgG natural infection profile, while 16.2% had a vaccination profile. Prevalence estimates for IgG due to natural infection ranged from 24.0% in week 2 to 9.7% in week 5, and for IgG due to vaccine from 4.4% in week 2 to 32.0% in week 6 (Table, Figure 2). Conclusion. Estimated SARS-CoV-2 IgG seroprevalence among patients at a medical center from January-March 2021 was 17% by natural infection, and 16% by vaccination. Weekly trends likely reflect community spread and vaccine uptake.

Compromised SARS-CoV-2 neutralizing antibody response in cord blood versus mothers

Background: Maternal antibodies are important for infant immunity, and understanding the maternal and umbilical cord antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection will be important for neonatal management and maternal vaccination strategies. Methods: The dynamics of maternal/ umbilical cord antibody responses to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein were analyzed in 81 samples from 69 pregnant women studied between April 2020 and January 2021. Binding IgG, IgA and IgM antibodies to RBD were measured by enzyme-linked immunosorbent assay (ELISA) in both maternal and cord blood. Neutralization was assessed using codon-optimized full-length G614 Spike-pseudotyped virus (VRC7480.D614G). Results: Among the 69 pregnant women, 57 were either symptomatic or asymptomatic infection and 17 samples were taken during the time of delivery resulting in paired maternal/umbilical cord blood samples. Among the maternal samples tested, the RBD specific IgG were detected in 93%, IgA were detected in 67% and IgM were detected in 79%. The RBD-specific IgG was detected in 12 of 17 (70%) umbilical cord blood, but IgM and IgA were not detected in the cord blood samples. The IgG antibody concentration were significantly (P < 0.004) lower (7 fold) in the cord blood when compared to maternal blood. However, the cord blood IgG titers were positively correlated with maternal IgG titers (r = 0.59;P < 0.003). In line with that, the circulating T-follicular helper cells (p<0.0001) and signaling lymphocytic activation molecule family 1(SLAMF1) were lower (p<0.004) in cord relative to maternal blood. Among the samples tested, 71.4% had neutralization titers. Interestingly, the neutralization capacity of plasma from cord blood was negative when compared to maternal blood (mean titer of 20 vs 2128 respectively), suggesting that cord blood does not have capacity to neutralize the SARS-CoV-2 virus. Conclusion: In this cohort study, maternal IgG, IgA and IgM antibodies to RBD of SARS-CoV-2 were seen in maternal samples. However the cord blood IgG levels were significantly lower and did not show positive titers for IgA and IgM. Although both maternal and cord blood has RBD binding antibodies, there is no neutralization seen in any of the cord blood tested compared to respective maternal blood. Our findings demonstrate that maternally-derived SARS-CoV-2 specific antibodies lack neutralization potential to provide neonatal protection from COVID-19. (Figure Presented).

An automated approach to determine antibody endpoint titers for COVID-19 by an enzyme-linked immunosorbent assay.

While a variety of therapeutic options continue to emerge for COVID-19 treatment, convalescent plasma (CP) has been used as a possible treatment option early in the pandemic. One of the most significant challenges with CP therapy, however, both when defining its efficacy and implementing its approach clinically, is accurately and efficiently characterizing an otherwise heterogenous therapeutic treatment. Given current limitations, our goal is to leverage a SARS antibody testing platform with a newly developed automated endpoint titer analysis program to rapidly define SARS-CoV-2 antibody levels in CP donors and hospitalized patients. A newly developed antibody detection platform was used to perform a serial dilution enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig)G, IgM, and IgA SARS-CoV-2 antibodies. Data were then analyzed using commercially available software, GraphPad Prism, or a newly developed program developed in Python called TiterScape, to analyze endpoint titers. Endpoint titer calculations and analysis times were then compared between the two analysis approaches. Serial dilution analysis of SARS-CoV-2 antibody levels revealed a high level of heterogeneity between individuals. Commercial platform analysis required significant time for manual data input and extrapolated endpoint titer values when the last serial dilution was above the endpoint cutoff, occasionally producing erroneously high results. By contrast, TiterScape processed 1008 samples for endpoint titer results in roughly 14 minutes compared with the 8 hours required for the commercial software program analysis. Equally important, results generated by TiterScape and Prism were highly similar, with differences averaging 1.26 ± 0.2 percent (mean ± SD). The pandemic has created unprecedented challenges when seeking to accurately test large numbers of individuals for SARS-CoV-2 antibody levels with a rapid turnaround time. ELISA platforms capable of serial dilution analysis coupled with a highly flexible software interface may provide a useful tool when seeking to define endpoint titers in a high-throughput manner. Immunohematology 2021;37:33-43.While a variety of therapeutic options continue to emerge for COVID-19 treatment, convalescent plasma (CP) has been used as a possible treatment option early in the pandemic. One of the most significant challenges with CP therapy, however, both when defining its efficacy and implementing its approach clinically, is accurately and efficiently characterizing an otherwise heterogenous therapeutic treatment. Given current limitations, our goal is to leverage a SARS antibody testing platform with a newly developed automated endpoint titer analysis program to rapidly define SARS-CoV-2 antibody levels in CP donors and hospitalized patients. A newly developed antibody detection platform was used to perform a serial dilution enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig)G, IgM, and IgA SARS-CoV-2 antibodies. Data were then analyzed using commercially available software, GraphPad Prism, or a newly developed program developed in Python called TiterScape, to analyze endpoint titers. Endpoint titer calculations and analysis times were then compared between the two analysis approaches. Serial dilution analysis of SARS-CoV-2 antibody levels revealed a high level of heterogeneity between individuals. Commercial platform analysis required significant time for manual data input and extrapolated endpoint titer values when the last serial dilution was above the endpoint cutoff, occasionally producing erroneously high results. By contrast, TiterScape processed 1008 samples for endpoint titer results in roughly 14 minutes compared with the 8 hours required for the commercial software program analysis. Equally important, results generated by TiterScape and Prism were highly similar, with differences averaging 1.26 ± 0.2 percent (mean ± SD). The pandemic has created unprecedented challenges when seeking to accurately test large numbers of individuals for SARS-CoV-2 antibody levels with a rapid turnaround time. ELISA platforms capable of serial dilution analysis coupled with a highly flexible software interface may provide a useful tool when seeking to define endpoint titers in a high-throughput manner. Immunohematology 2021;37:33­43.

Serum pooling for rapid expansion of anti-SARS-CoV-2 antibody testing capacity.

OBJECTIVES: Examine possible pooling strategies designed to expand SARS-CoV-2 serological testing capacity. METHODS: Negative pools were assessed to determine optimal optical density (OD) cutoffs, followed by spiking weak or strong positive samples to assess initial assay performance. Samples were then randomly subjected to pool and individual testing approaches. RESULTS: Single positive specimens consistently converted pools of 5, 10, or 20 into positive outcomes. However, weaker IgG-positive samples failed to similarly convert pools of 50 to a positive result. In contrast, a stronger individual positive sample converted all pools tested into positive outcomes. Finally, examination of 150 samples configured into pools of 5, 10, 20 or 50 accurately predicted the presence of positive or negative specimens within each pool. CONCLUSIONS: These results suggest that pooling strategies may allow expansion of serological testing capacity. While limitations exist, such strategies may aid in large-scale epidemiological screening or identification of optimal convalescent plasma donors.