ABSTRACT
Background. Vaccine-induced SARS-CoV-2 antibody responses are reduced in patients taking lymphocyte-depleting therapies, which are commonly prescribed for patients with idiopathic inflammatory myopathies (IIM). While a third vaccine dose (D3) augments the SARS-CoV-2 anti-spike response in some patients, there is a paucity of data on the humoral response following D3 in patients with IIM. Furthermore, the durability of antibody response is unknown. In this study, we evaluated serial antibody response for three months following a 3rd dose SARS-CoV-2 vaccination in IIM patients. Methods. Adults with a patient-reported diagnosis of idiopathic inflammatory myopathy who completed three-dose SARS-CoV-2 vaccination (two-dose BNT162b2 or mRNA-1273 followed by single mRNA or adenoviral vector dose) were recruited via social media campaign. Demographics and clinical characteristics were collected via patient report. Informed consent was provided electronically. Serial antibody responses were evaluated by the Roche Elecsys anti-SARS-CoV-2 S enzyme immunoassay, which measures total antibody to the SARS-CoV-2 S-receptor binding domain (RBD) protein (range 0. 4-2500U/ mL;positive >0.8U/mL). Poor antibody response was defined as anti-RBD titer <500U/mL based on predicted correlates of protective plasma neutralizing capacity. Those with prior COVID-19 infection were excluded. Associations were evaluated using Fisher's exact and Wilcoxon rank-sum tests as appropriate. Results. We evaluated serial anti-RBD titers in 59 participants (Table I). Most (93%) were female with median (IQR) age of 51 (41-62) years. Mycophenolate mofetil was the most frequently prescribed medication (45.6%). Participants completed primary vaccination with two-dose BNT162b2(54%) or mRNA-1273(46%). Median pre-D3 anti-RBD titer (IQR) was 65.8U/mL (4.6,473) at 158 (136-183) days following primary vaccination. Dose 3 included BNT162b2(47%), mRNA-1273(47%) or Ad.26.COV2.S (6%). Most (89.9%) received homologous D3 vaccination. 39% of participants reported holding peri-D3 immunosuppression with mycophenolate mofetil being the most commonly held medication in the peri-D3 period. Repeat anti-RBD testing was performed at a median (IQR) 30 (28-32) days post-D3. A higher antibody titer was seen in 89.9% participants following D3 with median (IQR) titer of 2500 U/mL (92,2500). Thirty-seven percent remained <500U/mL following D3;a greater proportion of these participants reported use of rituximab and greater number of immunosuppressive therapies compared to those with anti-RBD >=500U (72.7% versus 5.4%, p<0.001;3 therapies versus 2 therapies, p=0.03). Furthermore, 13.5% (8/59) remained below the threshold of positivity following D3;7/8 reported use of rituximab, 5/8 mycophenolate mofetil, or combination of these agents (4/8). There was not a significant difference in antibody titers among recipients of homologous/heterologous vaccination (p=0.22). Dose 3 was well tolerated with only 2 (3.4%) participants reporting disease flare requiring treatment within one month of vaccination;neither required intravenous therapy or hospital admission. Thirty-four (57.6%) participants underwent repeat anti-RBD testing three months following D3 with median (IQR) 2500U/mL (456,2500);73.53% (25/34) remained above threshold of >=500U/mL. Limitations of this study include small sample size and absence of healthy control group. Diagnosis was based on participant report and we did not routinely collect information on disease activity. Conclusion. We observed an augmented humoral response in most IIM patients following 3rd dose SARS-CoV-2 vaccination;antibody response was durable at three months. Dose 3 was well tolerated. Over 1/3 participants failed to develop adequate response following D3, namely those on rituximab therapy and on higher number of immunosuppressive therapies. These patients should be prioritized for prophylactic therapies to enhance protection against COVID-19 infection.
ABSTRACT
Purpose: Kidney transplant recipients (KTRs) have diminished immune response and protection after 2-dose mRNA COVID-19 vaccination. It is unknown if additional doses improve neutralization of variants of concern (VOC) in KTRs with prior poor seroresponse. Method(s): Adult KTRs with negative (<0.8 U/mL) or low (<=50 U/ml) anti-RBD Ig (Roche Elecsys anti-SARS-CoV-2-S) after 2-dose mRNA series were given a homologous 3rd dose (D3). Anti-RBD and VOC surrogate neutralization (%ACE2i) were measured 30 days post D3;responses were stratified by baseline anti-RBD. Reactogenicity, serial SARS-CoV-2 swabs, and donor-specific antibody (DSA) were assessed. Result(s): 81 KTRs (50% negative anti-RBD) received D3 (72% BNT162b2, 28% mRNA-1273) at median 167 days post D2 (Table). Median (IQR) anti-RBD increase was 410 (8-2309) U/mL with 69% (40% negative vs 98% low anti-RBD) achieving day 30 anti-RBD >50 U/ml (Fig1a). 22% remained seronegative. Non-response was associated with lower baseline lymphocyte count (median 770 vs 1160 cells/ uL;p=0.05) and IgG (median 779 vs 979 mg/dL;p<0.01), but not demographics, vaccine, or immunosuppressives. Median (IQR) delta variant %ACE2i increased from 6% (3-7) to 10% (4-22) (p<0.001), a 1% (0-5) increase in negative vs 13% (5-25) in low anti-RBD. %ACE2i was linearly associated with anti-RBD >=100 U/ mL (all VOC shown in Fig1b);64% of KTRs with anti-RBD >=250 U/mL had delta %ACE2i >20. There were 3 cases of mild-moderate COVID-19 >=7 days post-D3, with pre-infection anti-RBD <0.4, 22, 76 U/mL and delta %ACE2i 6, 9, and 16, respectively. There was no acute rejection, nor increased or de novo DSA. Conclusion(s): A 3rd mRNA vaccine dose increased anti-RBD and VOC neutralization in KTRs without inducing clinical alloimmunity, yet 45% with negative baseline anti-RBD remained seronegative without delta variant neutralization. Trials are ongoing to test immune response augmentation in this subgroup via temporary immunosuppression reduction or heterologous boosting.
ABSTRACT
Purpose: Liver transplant (LT) recipients have a decreased response to 2 doses of SARS-CoV-2 vaccine compared to the general population, so we aimed to understand response to a third dose to inform vaccination strategies. Method(s): LT recipients in our observational cohort who received 3 homologous mRNA vaccines and available antibody levels pre- and post-dose 3 (D3) were identified. Those who reported a prior COVID-19 diagnosis or used belatacept were excluded. The peak anti-spike antibody level collected between the second (D2) and third dose (D3), was compared to the antibody level at 1 month post-D3. Samples were tested with Roche Elecsys Anti-Sars-CoV-2 enzyme immunoassay (EIA) (positive >=0.8 U/mL) or EUROIMMUN EIA (positive >=1.1 AU). Result(s): 146 participants completed 3 homologous doses of BNT162b2 (53%) or mRNA-1273 (47%) vaccines between 5/15/2021 - 11/8/2021. The median (IQR) time of peak pre-D3 antibody collection was 89 (31, 104) days post-D2. The median time of 1-month post-D3 antibody collection was 30 (23, 33) days. The median time between D2 and D3 was 168 (149-188) days. Overall, 125/146 (86%) were seropositive pre-D3, and 139/146 (95%) were seropositive post-D3 (Figure 1). There were no seroreversions post D3, and among the 21 seronegative recipients pre-D3, 14 (67%) seroconverted post-D3. Risk factors significantly associated with persistent seronegativity post-D3 were less time since LT (1.3 vs 6 years, p=0.042), mycophenolate use (100% vs 37%, p=0.001), BNT162b2 series (100% vs 50%, p=0.01), and pre-D3 seronegative status (86% vs 10%, p<0.001). Conclusion(s): Most LT recipients have excellent responses to a third homologous mRNA vaccine dose, greater than that seen in other transplant recipients. Persons seronegative after D2, however, show weaker response and may remain at high risk for SARS-CoV-2 infection despite D3.
ABSTRACT
Purpose: This study compares SARS-CoV-2 antibody responses between the twodose mRNA-1273 and BNT162b2 vaccine series across groups of incrementally immunosuppressed patients. Method(s): Semiquantitative testing for antibodies against the receptor binding domain (RBD) of the SARS-CoV-2 spike protein was performed using the Roche Elecsys anti-SARS-CoV-2 S enzyme immunoassay (EIA), 15-45 days after the second vaccine dose for SARS-CoV-2 naive patients with rheumatic and musculoskeletal disease (RMD), and solid organ transplant recipients (SOTRs) from an observational cohort. Anti-RBD titers were divided into categories of >=50, >=100 and >=250 U/mL based on levels associated with plasma neutralizing capacity in COVID-19 convalescent patients. Participants were stratified by increasing intensity of immunosuppression: RMD not on immunosuppression, RMD on immunosuppression, SOTR not on mycophenolate (MMF), and SOTR on MMF. Response rates between mRNA-1273 and BNT162b2 recipients were compared using modified Poisson regression weighted for age, time since vaccination, and number of immunosuppressive medications. This analysis was repeated for several thresholds of positive response: 50, 100, and 250 U/mL. Result(s): Of 1868 participants, 55.8% of RMD and 52.7% of SOTRs received BNT162b2;the remainder received mRNA-1273. Demographics, diagnoses, and immunosuppressive regimens were similar across vaccine groups. Among RMD participants not on immunosuppression, the chance of anti-RBD >=250U/ml was comparable among BNT162b2 and mRNA-1273 recipients (IRR= 0.91 1.03 1.16 p= 0.67). mRNA-1273 recipients had a higher chance than BNT162b2 recipients to achieve anti-RBD >=250U/ml among RMD participants on immunosuppression (IRR = 1.15 1.241.34, p<0.001);SOTRs not on MMF (IRR = 1.24 1.561.96, p <0.001);and SOTRs on MMF (IRR=1.28 2.625.37, p= 0.01). Similar trends were observed with titer cutoffs of >=100 and >=50 U/mL (Table 1). Conclusion(s): The two-dose mRNA-1273 vaccine series was more likely to induce stronger humoral immunogenicity compared to BNT162b2 in immunosuppressed patients;this effect was more pronounced with greater immunosuppression. These findings suggest importance in the choice of mRNA vaccine platform in optimizing immune responses to SARS-CoV-2 vaccination and can help inform vaccination strategies for booster doses in high-risk, immunosuppressed populations.
ABSTRACT
Purpose: Kidney transplant recipients taking belatacept (KTR-B) have poor immune response to two-dose SARS-CoV-2 vaccination. We sought to characterize the impact of an additional vaccine dose on plasma neutralizing capacity and cellular responses as compared to that of KTRs controls (KTR-C) not taking belatacept. Method(s): Within an observational cohort, we tested 26 KTR-Bs and 27 KTR-Cs for anti-spike antibody responses before and after a third SARS-CoV-2 vaccine dose (D3) using two clinical assays (Roche Elecsys anti-S Ig and EUROIMMUN anti-S1 IgG). For a subset of 5 KTR-Bs and for all KTR-Cs we used a research assay (Meso Scale Diagnostics V-Plex [MSD]) to further assess anti-spike and RBD IgG, as well as surrogate plasma neutralizing activity (% ACE2 inhibition) versus the ancestral and delta variants. For 3 KTR-Bs, post D3 T cell response was assessed via IFN-y ELISpot and deemed positive if spot forming units > 20 per million PBMC and stimulation index > 3. Result(s): KTR-Bs had significant lower clinical anti-spike seroconversion than KTR-Cs (31% vs 74%, p=0.001) after D3 despite similar demographics, clinical factors, and vaccines administered (Table 1). No KTR-B (0/5) was seropositive by MSD anti-spike or anti-RBD IgG (Figure 1). % ACE2 inhibition versus the ancestral variant was significantly lower in KTR-Bs than in KTR-Cs (Median [IQR] 5.2 [2.8, 6.5] vs 12.5 [7.7, 23.9], p<0.01);all KTR-Bs were below a level consistent with detectable neutralizing antibody. All tested KTR-Bs (3/3) had a negative ELISpot, consistent with negligible cellular response. Conclusion(s): These results suggest minimal humoral or cellular immunogenicity of additional vaccine doses for KTR-Bs and indicates the need for alternative strategies to improve vaccine response such as immunosuppression alteration or use of passive immunoprophylaxis with monoclonal anti-spike antibody to improve protection versus SARS-CoV-2.
ABSTRACT
Purpose: Solid organ transplant recipients (SOTRs) are at increased risk for severe COVID-19 and exhibit lower antibody responses to SARS-CoV-2 vaccines. This study aimed to determine if pre-vaccination cytokine levels are associated with antibody response to SARS-CoV-2 vaccination. Method(s): A cross-sectional study was performed among 58 SOTRs before and after two-dose mRNA vaccine series, 35 additional SOTRs before and after a third vaccine dose, with comparison to 16 healthy controls (HCs). Anti-spike antibody was assessed using the IgG Euroimmun ELISA. Electrochemiluminescence detectionbased multiplexed sandwich immunoassays were used to quantify plasma cytokine and chemokine concentrations (n=20 analytes). Concentrations between SOTRs and HCs, stratified by ultimate antibody response to the vaccine, were compared using Wilcoxon-rank-sum test with false discovery rates (FDR) computed to correct for multiple comparisons. Result(s): In the study population, 100% of HCs, 59% of SOTRs after two doses and 63% of SOTRs after three doses had a detectable antibody response. Multiple baseline cytokines were elevated in SOTRs versus HCs. There was no significant difference in cytokine levels between SOTRs with high vs low-titer antibodies after two doses of vaccine. However, as compared to poor antibody responders, SOTRs who went on to develop a high-titer antibody response to a third dose of vaccine had significantly higher pre-third dose levels of several innate immune cytokines including IL-17, IL-2Ra, IL-6, IP-10, MIP-1alpha, and TNF-alpha (FDR <0.05). Conclusion(s): A specific inflammatory profile or immune state may identify which SOTRs are likely to develop stronger sero-response and possible protection after a third dose of SARS-CoV-2 vaccine.
ABSTRACT
Purpose: The impact of antigenic imprinting, when immune memory of one antigen influences the response to subsequent similar antigens, on the antibody response in solid organ transplant recipients (SOTRs) after SARS-CoV-2 vaccination is currently unknown. This study examines the relationship between seasonal coronaviruses (sCoV) and SARS-CoV-2 antibody levels pre- and post-vaccination in SOTRs. Method(s): Plasma from 52 SOTRs pre- and post-SARS-CoV-2 vaccination (2 doses, mRNA) was analyzed using the Meso Scale Diagnostic Coronavirus Panel 3 (an electrochemiluminescence detection-based multiplexed sandwich immunoassay) for IgG antibodies against alpha sCoVs (229E, NL63), beta sCoVs (HKU1, OC43), and SARS-CoV-2 spike proteins. Changes in IgG titers were determined by paired Wilcoxon rank-sum tests. Spearman correlation analysis was used to determine associations between pre-vaccination anti-sCoVs and post-vaccination anti-SARS-CoV-2 IgG. Result(s): Vaccination increased both anti-SARS-CoV-2 (fold change (FC) 1.9, p<0.001) and anti-beta sCoV (HKU1 [FC 0.05, p<0.001], OC43 [FC 0.8, p<0.001]) IgG titers in SOTRs, but did not increase anti-alpha sCoV IgG. Furthermore, prevaccination anti-beta sCoV (HKU1 [rho= -0.3, p=0.03], OC43 [rho= -0.3, p<0.03]) IgG titers were negatively correlated with post-vaccination anti-SARS-CoV-2 IgG. Conclusion(s): These exploratory findings suggest that prior exposure to seasonal betacoronaviruses may lead to antigenic imprinting in SOTRs that negatively impacts the antibody response to vaccination against the novel pandemic betacoronavirus, SARS-CoV-2.
ABSTRACT
Purpose: Humoral response to COVID-19 vaccines is attenuated in many solid organ transplant recipients (SOTRs), necessitating additional primary and booster vaccinations. The omicron variant demonstrates substantial immune evasion, and it is not known if boosters increase neutralizing capacity versus omicron among SOTRs. We therefore investigated SOTR antibody response and neutralization versus variants of concern (VOC) including omicron to a 4th vaccine dose (D4). Method(s): Within a national, prospective observational cohort, 25 SOTRs underwent anti-SARS-CoV-2 spike and receptor binding domain (RBD) IgG testing using the Meso Scale Discovery platform before and 2-4 weeks after D4. Surrogate neutralization (%ACE2 inhibition [%ACE2i], range 0-100% with >20% correlating with live virus neutralization), was measured versus full spike proteins of the ancestral ("vaccine") strain and 5 VOCs including delta and omicron. Change in IgG level and %ACE2i were compared using paired Wilcoxon rank-sum testing. Result(s): Demographics are outlined in Table 1, including median (IQR) age 59 (45- 55) years, 64% kidney recipients, and D4 receipt (60% Moderna, 40% Pfizer) median (IQR) 93 days (28-134) post D3. Two participants had SARS-CoV-2 exposure per anti-nucleocapsid testing, including one incident infection. Overall, anti-RBD (92%- >100%) and anti-spike (84%->92%) seropositivity increased after D4, as did median (IQR) anti-spike IgG 42.3 (4.9-134.2)->228.9 (115.4-655.8) WHO binding antibody units (p<0.05). Median (IQR) %ACE2i significantly increased after D4 vs the vaccine strain 5.8% (0-16.8)->20.6% (5.8-45.9) and delta variant 9.1% (4.9-12.8)->17.1% (10.3-31.7) (both p<0.001). In contrast, no SOTR showed neutralization vs omicron before or after D4: median (IQR) %ACE2i 4.1% (0-6.9)->0.5% (0-5.7) (p=0.11). Conclusion(s): Although a 4th vaccine dose increased anti-spike IgG and neutralizing capacity vs some VOC, there was no omicron variant neutralization among SOTRs. SOTRs may remain at high risk for SARS-CoV-2 infection despite boosting, thus additional protective interventions should be urgently explored. (Figure Presented).
ABSTRACT
Purpose: Understanding the dynamics of antibody response to a third dose (D3) of anti-SARS-CoV-2 vaccine in solid organ transplant recipients (SOTRs) is important to inform booster strategies. Method(s): We studied the the dynamics of anti-RBD (Roche, <0.8 to >2500 U/dL) and anti-S (Euroimmun, 0.1 to >8.9 AU) antibody levels in a cohort of SOTRs at 2 weeks, 1 month and 3 months after D3. We compared the proportion of seroconversion at 1 month or 3 months after D3 between mRNA and Ad.26.COV2.S D3 recipients, using Poisson regression with robust standard error, adjusting for age and numbers of immunosuppressants. Result(s): Among 928 SOTRs with 2-week (n=655), 1-month (n=651) or 3-month (n=404) post-D3 titer, 78%, 82% and 86% tested positive for antibodies. The median (IQR) anti-RBD at the three timepoints were >2500 (73, >2500), 2494 (49, >2500) and 1234 (59, >2500) U/mL (Figure 1A, blue), and there were 61% (n=436), 60% (n=491) and 53% (n=313) with anti-RBD> 1000 u/mL, respectively. The median (IQR) anti-S at the three timepoints were 3.2 (0.3, 8.4), 8 (2, >8.9) and 7.4 (2, >8.9) AU (Figure 1B, blue), and there were 47% (n=218), 61% (n=161) and 64% (n=91) who developed anti-S>4 AU. Among patients with no or minimal immune response at 2 weeks post-D3 (n=102), 3/41 (7%) had increased anti-RBD by 1 month while 11/18 (61%) had increased anti-S (Fisher exact p<0.001). 6/29 (21%) had increased anti-RBD by 3 months while 12/20 (60%) had increased anti-S (p<0.01) (Figure 1A&B, yellow). 27/102 (27%) of them seroconverted at 1 or 3 months after D3. Having received Ad.26.COV2.S as D3 is associated with 3.9X increased proportion of seroconversion at 1 month or 3 months among patients with no or minimal immune response at 2 weeks after D3 (aIRR=2.223.926.92, p<0.001). Conclusion(s): Among SOTRs who received a booster anti-SARS-CoV-2 vaccination, dynamics of Anti-RBD and Anti-S antibodies differed substantially. Anti-RBD titers on average declined only slightly after 14 days post-D3, while anti-S increased up through 30-60 days post-D3. After the peak, average titer values for both antibodies declined slightly through three months post-D3.
ABSTRACT
Purpose: nti-spike antibody response to SARS-CoV-2 vaccination is diminished in LT recipients compared to the general population so understanding durability for those that do respond is critical to mitigating risks of infection. We measured serial antibody titers in LT recipients for 6 months after two-dose mRNA vaccine series to describe kinetics and sero-reversion rates. Method(s): LT recipients without known prior COVID-19 had anti-spike antibody testing at 1, 3, and 6 months after the second dose of mRNA vaccine (D2) using two commercial assays (Roche Elecsys anti-receptor binding domain immunoassay (EIA) [positive >=0.8 U/mL] or EUROIMMUN anti-S1 EIA [positive >=1.1 AU]). We compared titer distributions over time and identified factors associated with sero-reversion. Result(s): 180 LT recipients received BNT162b2 (48%) or mRNA-1273 (52%) 2-dose series between 1/7/2021-5/7/2021. At 1 month post-D2 (n=173), 146 (84%) had positive antibody levels at a median (IQR) of 30 (28, 32) days post-D2. At 3 months post-D2 (n=164), 149 (91%) had positive levels at a median of 92 (90, 96) days post-D2. At 6 months post-D2 (n=73), 62 (85%) had positive levels at a median of 180 (176, 185) days post-D2. Among the 66 seropositive at 1 or 3 months post-D2, 58 (88%) remained seropositive by 6 months post-D2. Neither age, years since transplant, vaccine type, nor mycophenolate (MMF) use were associated with sero-reversion, though there was a trend toward more triple immunosuppressive use (25% vs 3%, p=0.07). Of those Roche-tested, the median anti-RBD levels were >=250 U/mL (14, >=250;n=120) at 1 month post-D2, >=250 U/mL (58, >=250;n=113) at 3 months, and >=250 U/mL (30, >=250;n=49) at 6 months . Of those EUROIMMUN-tested, the median anti-S1 levels were 7.25 AU (4.31, 8.71;n=53) at 1 month, 5.71 AU (1.27, 7.90;n=51) at 3 months, and 1.73 AU (0.76, 6.01;n=25) at 6 months. Conclusion(s): Overall, most LT recipients demonstrated 6 month durability of anti-spike antibody following vaccination, but a subset did sero-revert, potentially associated with heavier immunosuppression. Further investigation into clinical consequences of waning antibody levels is key to guide timing of additional vaccine doses.