Humoral immune responses remain quantitatively impaired but improve qualitatively in anti-CD20 treated patients with multiple sclerosis after three or four COVID-19 vaccinations

BackgroundHumoral immune responses to COVID-19 vaccination are diminished in anti-CD20 treated patients with multiple sclerosis (pwMS). In healthy individuals, neutralizing antibodies against the SARS-CoV-2 Omicron variant are only detected after three COVID-19 vaccinations. It was hitherto unknown whether a third or fourth COVID-19 vaccination of anti-CD20 treated pwMS improves SARS-CoV-2 specific humoral immune responses, including neutralizing antibodies against Omicron. MethodsAnti-CD20 treated pwMS vaccinated two (n=61), three (n=57) or four (n=15) times and healthy controls (n=10) vaccinated thrice were included in a prospective cohort study. Anti-SARS-CoV-2 spike S1 IgG and IgA levels, maturation of SARS-CoV-2 IgG avidity, neutralizing capacity against the SARS-CoV-2 Omicron BA.2 variant and SARS-CoV-2 specific T cell responses were analyzed. ResultsThe proportion of anti-CD20 treated pwMS with detectable SARS-CoV-2 S1 IgG was similar after the second (31/61, 50.8%), third (31/57, 54.4%) and fourth (8/15, 53.3%) vaccination. In pwMS with detectable SARS-CoV-2 IgG, the proportion with high affinity antibodies increased from the second (6/31, 19.4%) to the third (17/31, 54.8%) and fourth (6/8, 75%) vaccination. While none (0/10) of the anti-CD20 treated pwMS vaccinated twice had Omicron specific neutralizing antibodies, 3/10 (30%) pwMS vaccinated thrice and 3/5 (60%) pwMS vaccinated four times generated Omicron specific neutralizing antibodies. ConclusionAlthough SARS-CoV-2 specific humoral immune responses remain quantitatively impaired, in those anti-CD20 treated pwMS who do develop SARS-CoV-2 antibodies, the functionality of SARS-CoV-2 antibodies, including neutralizing antibodies against Omicron, improves after three and four SARS-CoV-2 vaccinations, supporting current recommendations for one or two booster vaccination in anti-CD20 treated pwMS.

Pausing methotrexate improves immunogenicity of COVID-19 vaccination in patients with rheumatic diseases

ObjectiveTo study the effect of methotrexate (MTX) and its discontinuation on the humoral immune response after COVID-19 vaccination in patients with autoimmune rheumatic diseases (AIRD). MethodsIn this retrospective study, neutralising SARS-CoV-2 antibodies were measured after second vaccination in 64 rheumatic patients on methotrexate therapy, 31 of whom temporarily paused medication without a fixed regimen. The control group consisted of 21 AIRD patients without immunosuppressive medication. ResultsMTX patients showed a significantly lower mean antibody response compared to AIRD patients without immunosuppressive therapy (71.8 % vs 92.4 %, p<0.001). For patients taking MTX, age correlated negatively with immune response (r=-0.49; p<0.001). All nine patients with antibody levels below the cut-off were older than 60 years. Patients who held MTX during at least one vaccination showed significantly higher mean neutralising antibody levels after second vaccination, compared to patients who continued MTX therapy during both vaccinations (83.1 % vs 61.2 %, p=0.001). This effect was particularly pronounced in patients older than 60 years (80.8 % vs 51.9 %, p=0.001). The impact of the time period after vaccination was greater than of the time before vaccination with the critical cut-off being 10 days. ConclusionMTX reduces the immunogenicity of SARS-CoV-2 vaccination in an age-dependent manner. Our data further suggest that holding MTX for at least 10 days after vaccination significantly improves the antibody response in patients over 60 years of age.

A cohort of 222 anti-CD20 treated patients with multiple sclerosis followed through the COVID-19 pandemic: Attenuated humoral but robust cellular immune responses after vaccination and infection

ObjectiveTo analyze humoral and cellular immune responses to SARS-CoV-2 vaccinations and infections in anti-CD20 treated patients with multiple sclerosis (pwMS). Methods181 pwMS on anti-CD20 therapy and 41 pwMS who began anti-CD20 therapy were included in a prospective, observational, single-center cohort study between March 2020 and August 2021. 51 pwMS under anti-CD20 treatment, 14 anti-CD20 therapy-naive pwMS and 19 healthy controls (HC) were vaccinated twice against SARS-CoV-2. We measured SARS-CoV-2 spike protein (full-length, S1 domain and receptor binding domain) immunoglobulin (Ig)G and S1 IgA and virus neutralizing capacity and avidity of SARS-CoV-2 antibodies. SARS-CoV-2 specific T cells were determined by interferon-{gamma} release assays. ResultsFollowing two SARS-CoV-2 vaccinations, levels of IgG and IgA antibodies to SARS-CoV-2 spike protein as well as neutralizing capacity and avidity of SARS-CoV-2 IgG were lower in anti-CD20 treated pwMS than in anti-CD20 therapy-naive pwMS and in HC (p<0.003 for all pairwise comparisons). However, in all anti-CD20 treated pwMS vaccinated twice (n=26) or infected with SARS-CoV-2 (n=2), in whom SARS-CoV-2 specific T cells could be measured, SARS-CoV-2 specific T cells were detectable, at levels similar to those of twice-vaccinated anti-CD20 therapy-naive pwMS (n=7) and HC (n=19). SARS-CoV-2 S1 IgG levels (r=0.42, p=0.002), antibody avidity (r=0.7, p<0.001) and neutralizing capacity (r=0.44, p=0.03) increased with time between anti-CD20 infusion and second vaccination. Based on detection of SARS-CoV-2 antibodies, SARS-CoV-2 infections occurred in 4/175 (2.3%) anti-CD20 treated pwMS, all of whom recovered fully. InterpretationThese findings should inform treatment decisions and SARS-CoV-2 vaccination management in pwMS.

Serum but not mucosal antibody responses are predicted by pre-existing SARS-CoV-2 spike cross-reactive CD4+ T cells following BNT162b2 vaccination in the elderly

Advanced age is a main risk factor for severe COVID-19. However, low vaccination efficacy and accelerated waning immunity have been reported in this age group. To elucidate age-related differences in immunogenicity, we analysed human cellular, serological and salivary SARS-CoV-2 spike glycoprotein-specific immune responses to BNT162b2 COVID-19 vaccine in old (69-92 years) and middle-aged (24-57 years) vaccinees compared to natural infection (COVID-19 convalescents, 21-55 years). Serological humoral responses to vaccination exceeded those of convalescents but salivary anti-spike subunit 1 (S1) IgA and neutralizing capacity were less durable in vaccinees. In old vaccinees, we observed that pre-existing spike-specific CD4+ T cells are associated with efficient induction of anti-S1 IgG and neutralizing capacity in serum but not saliva. Our results suggest pre-existing SARS-CoV-2 cross-reactive CD4+ T cells as predictor of an efficient COVID-19 vaccine-induced humoral immune response in old individuals.

SARS-CoV-2 Beta variant infection elicits potent lineage-specific and cross-reactive antibodies

SARS-CoV-2 Beta variant of concern (VOC) resists neutralization by major classes of antibodies from non-VOC COVID-19 patients and vaccinated individuals. Here, serum of Beta variant infected patients revealed reduced cross-neutralization of non-VOC virus. From these patients, we isolated Beta-specific and cross-reactive receptor-binding domain (RBD) antibodies. The Beta-specificity results from recruitment of novel VOC-specific clonotypes and accommodation of VOC-defining amino acids into a major non-VOC antibody class that is normally sensitive to these mutations. The Beta-elicited cross-reactive antibodies share genetic and structural features with non-VOC-elicited antibodies, including a public VH1-58 clonotype targeting the RBD ridge independent of VOC mutations. These findings advance our understanding of the antibody response to SARS-CoV-2 shaped by antigenic drift with implications for design of next-generation vaccines and therapeutics. One sentence summarySARS-CoV-2 Beta variant elicits lineage-specific antibodies and antibodies with neutralizing breadth against wild-type virus and VOCs.

Long-term immunogenicity of BNT162b2 vaccination in the elderly and in younger health care workers

COVID-19 mRNA vaccine BNT162b2 is highly immunogenic and effective, but recent studies have indicated waning anti-SARS-CoV-2 immune responses over time. Increasing infection rates has led authorities in several countries to initiate booster campaigns for vulnerable populations, including the elderly. However, the durability of vaccine-induced immunity in the elderly is currently unknown. Here, we describe interim results of a prospective cohort study comparing immune responses in a cohort of vaccinated elderly persons to those in healthcare workers (HCW), measured six months after first immunisation with BNT162b2. Anti-SARS-CoV-2 S1-, full Spike- and RBD-IgG seropositivity rates and IgG levels at six months were significantly lower in the elderly compared to HCW. Serum neutralization of Delta VOC measured by pseudovirus neutralisation test was detectable in 43/71 (60.6%, 95%CI: 48.9-71.1) in the elderly cohort compared to 79/83 in the HCW cohort (95.2%, 95%CI: 88.3-98.1) at six months post vaccination. Consistent with the overall lower antibody levels, SARS-CoV-2-S1 T cell reactivity was reduced in the elderly compared to HCW (261.6 mIU/ml, IQR:141.5-828.6 vs 1198.0 mIU/ml, IQR: 593.9-2533.6, p<0.0001). Collectively, these findings suggest that the established two-dose vaccination regimen elicits less durable immune responses in the elderly compared to young adults. Given the recent surge in hospitalisations, even in countries with high vaccination rates such as Israel, the current data may support booster vaccinations of the elderly. Further studies to determine long-term effectiveness of COVID-19 vaccines in high-risk populations and the safety and effectiveness of additional boosters are needed.

Reactogenicity of homologous and heterologous prime-boost immunization with BNT162b2 and ChAdOx1-nCoV19: a prospective cohort study

Heterologous prime-boost vaccination is of increasing interest for COVID-19 vaccines. Evidence of rare thrombotic events associated with ChAdOx1-nCoV19 (Vaxzevria, ChAdOx) has lead several European countries to recommend a heterologous booster with mRNA vaccines for certain age groups (e.g. persons <60years in Germany), who have already received one dose of ChAdOx, although data on reactogenicity and safety of this vaccination regimen are still missing. Here we report reactogenicity data of homologous BNT162b2 (Comirnaty, BNT) or heterologous ChAdOx/BNT prime-boost immunisations in a prospective observational cohort study of 326 healthcare workers. Reactogenicity of heterologous ChAdOx/BNT booster vaccination was largely comparable to homologous BNT/BNT vaccination and overall well-tolerated. No major differences were observed in the frequency or severity of local reactions after either of the vaccinations. In contrast, notable differences between the regimens were observed for systemic reactions, which were most frequent after prime immunisation with ChAdOx (86%, 95CI: 79-91), and less frequent after homologous BNT/BNT (65%, 95CI: 56-72), or heterologous ChAdOx/BNT boosters (48%, 95CI: 36-59). This interim analysis supports the safety of currently recommended heterologous ChAdOx/BNT prime-boost immunisations with 12-week intervals.

Immunogenicity of COVID-19 Tozinameran Vaccination in Patients on Chronic Dialysis

ObjectivePatients with kidney failure have notoriously weak responses to common vaccines. Thus, immunogenicity of novel SARS-CoV-2 vaccines might be impaired in this group. To determine immunogenicity of SARS-CoV-2 vaccination in patients with chronic dialysis, we analyzed the humoral and T-cell response after two doses of mRNA vaccine Tozinameran (BNT162b2 BioNTech/Pfizer). Design, Settings, and ParticipantsThis observational study included 43 patients on dialysis before vaccination with two doses of Tozinameran 21 days apart. Overall, 36 patients completed the observation period. Serum samples were analyzed by SARS-CoV-2 specific antibodies [~]1 and [~]3-4 weeks after the second vaccination. In addition, SARS-CoV-2-specific T-cell responses were assessed at the later time point by an interferon-gamma release assay (IGRA). Outcomes at later timepoints were compared to a group of 44 elderly patients with no dialysis after immunization with Tozinameran. ExposuresBlood drawings during regular laboratory routine assessment right before start of dialysis therapy or at the time of vaccination and at follow-up study visits. Main Outcomes and MeasuresAssessment of immunogenicity after vaccination against SARS-CoV-2 in patients on and without dialysis. ResultsMedian age of patients on chronic dialysis was 74.0 years (IQR 66.0, 82.0). The proportion of males was higher (69.4%) than females. Only 20/36 patients (55.6%, 95%CI: 38.29-71.67) developed SARS-CoV-2-IgG antibodies at first sampling, whereas 32/36 patients (88.9%, 95%CI:73.00-96.38) demonstrated seropositivity at the second sampling. Seroconversion rates and antibody titers were significantly lower compared to a cohort of vaccinees with similar age but no chronic dialysis (>90% seropositivity). SARS-CoV-2-specific T-cell responses 3 weeks after second vaccination were detected in 21/31 vaccinated dialysis patients (67.7%, 95%CI: 48.53-82.68) compared to 42/44 (93.3%, 95%CI: 76.49-98.84) in controls of similar age. Conclusion and RelevancePatients on dialysis demonstrate a delayed, but robust immune response three weeks after the second dose, which indicates effective vaccination of this vulnerable group. However, the lower immunogenicity of Tozinameran in these patients needs further attention to develop potential countermeasures such as an additional booster vaccination.

Cross-reactive CD4+ T cells enhance SARS-CoV-2 immune responses upon infection and vaccination

While evidence for pre-existing SARS-CoV-2-cross-reactive CD4+ T cells in unexposed individuals is increasing, their functional significance remains unclear. Here, we comprehensively determined SARS-CoV-2-cross-reactivity and human coronavirus-reactivity in unexposed individuals. SARS-CoV-2-cross-reactive CD4+ T cells were ubiquitous, but their presence decreased with age. Within the spike glycoprotein fusion domain, we identified a universal immunodominant coronavirus-specific peptide epitope (iCope). Pre-existing spike- and iCope-reactive memory T cells were efficiently recruited into mild SARS-CoV-2 infections and their abundance correlated with higher IgG titers. Importantly, the cells were also reactivated after primary BNT162b2 COVID-19 mRNA vaccination in which their kinetics resembled that of secondary immune responses. Our results highlight the functional importance of pre-existing spike-cross-reactive T cells in SARS-CoV-2 infection and vaccination. Abundant spike-specific cross-immunity may be responsible for the unexpectedly high efficacy of current vaccines even with single doses and the high rate of asymptomatic/mild infection courses.

A SARS-CoV-2 neutralizing antibody protects from lung pathology in a COVID-19 hamster model

The emergence of SARS-CoV-2 led to pandemic spread of coronavirus disease 2019 (COVID-19), manifesting with respiratory symptoms and multi-organ dysfunction. Detailed characterization of virus-neutralizing antibodies and target epitopes is needed to understand COVID-19 pathophysiology and guide immunization strategies. Among 598 human monoclonal antibodies (mAbs) from ten COVID-19 patients, we identified 40 strongly neutralizing mAbs. The most potent mAb CV07-209 neutralized authentic SARS-CoV-2 with IC50 of 3.1 ng/ml. Crystal structures of two mAbs in complex with the SARS-CoV-2 receptor-binding domain at 2.55 and 2.70 [A] revealed a direct block of ACE2 attachment. Interestingly, some of the near-germline SARS-CoV-2 neutralizing mAbs reacted with mammalian self-antigens. Prophylactic and therapeutic application of CV07-209 protected hamsters from SARS-CoV-2 infection, weight loss and lung pathology. Our results show that non-self-reactive virus-neutralizing mAbs elicited during SARS-CoV-2 infection are a promising therapeutic strategy.