Stéphane Grillet

Impact of synthetic and biologic disease‐modifying antirheumatic drugs on antibody responses to the AS03‐adjuvanted pandemic influenza vaccine: A prospective, open‐label, parallel‐cohort, single‐center study

OBJECTIVE To identify the determinants of antibody responses to adjuvanted split influenza A (H1N1) vaccines in patients with inflammatory rheumatic diseases. METHODS One hundred seventy-three patients (82 with rheumatoid arthritis, 45 with spondylarthritis, and 46 with other inflammatory rheumatic diseases) and 138 control subjects were enrolled in this prospective single-center study. Controls received 1 dose of adjuvanted influenza A/09/H1N1 vaccine, and patients received 2 doses of the vaccine. Antibody responses were measured by hemagglutination inhibition assay before and 3-4 weeks after each dose. Geometric mean titers (GMTs) and rates of seroprotection (GMT≥40) were calculated. A comprehensive medical questionnaire was used to identify the determinants of vaccine responses and adverse events. RESULTS Baseline influenza A/09/H1N1 antibody levels were low in patients and controls (seroprotection rates 14.8% and 14.2%, respectively). A significant response to dose 1 was observed in both groups. However, the GMT and the seroprotection rate remained significantly lower in patients (GMT 146 versus 340, seroprotection rate 74.6% versus 87%; both P<0.001). The second dose markedly increased antibody titers in patients, with achievement of a similar GMT and seroprotection rate as elicited with a single dose in healthy controls. By multivariate regression analysis, increasing age, use of disease-modifying antirheumatic drugs (DMARDs) (except hydroxychloroquine and sulfasalazine), and recent (within 3 months) B cell depletion treatment were identified as the main determinants of vaccine responses; tumor necrosis factor α antagonist treatment was not identified as a major determinant. Immunization was well tolerated, without any adverse effect on disease activity. CONCLUSION DMARDs exert distinct influences on influenza vaccine responses in patients with inflammatory rheumatic diseases. Two doses of adjuvanted vaccine were necessary and sufficient to elicit responses in patients similar to those achieved with 1 dose in healthy controls.

Varicella‐Zoster Immunization in Pediatric Liver Transplant Recipients: Safe and Immunogenic

Varicella can have a severe course in immunosuppressed patients. Although prevention is fundamental, live‐attenuated varicella‐zoster (VZV) vaccine is not currently recommended in transplant recipients. Our aims were to (1) evaluate VZV immunity in pediatric liver transplant (LT) recipients; (2) immunize (two doses) seronegative patients post‐LT; (3) monitor vaccine safety, (4) assess B and T cell vaccine responses. All patients followed at the Swiss National Pediatric LT Center were approached and 77/79 (97.5%) were enrolled (median age 7.8 years). Vaccine safety was monitored by standardized diary cards and phone calls. VZV‐specific serology and CD4+ T cells were assessed before and after immunization. Thirty‐nine patients (51.1%) were seronegative including 14 children immunized pre‐LT. Thirty‐six of 39 seronegative patients were immunized post‐LT (median 3.0 years post LT). Local (54.8%) and systemic (64.5%) reactions were mild and transient. The frequency of VZV‐specific CD4+ T cells and antibody titers increased significantly (respectively from 0.085% to 0.16%, p = 0.04 and 21.0 to 1134.5 IU/L, p < 0.001). All children reached seroprotective titers and 31/32 (97%) patients assessed remained seroprotected at follow‐up (median 1.7 years). No breakthrough disease was reported during follow‐up (median 4.1 years). Thereby, VZV vaccine appears to be safe, immunogenic and provide protection against disease in pediatric LT patients.

Responses of solid organ transplant recipients to the AS03-adjuvanted pandemic influenza vaccine.

BACKGROUND Solid organ transplant (SOT) recipients are a priority group for influenza vaccination and strategies enhancing immunogenicity are needed. METHODS We determined adverse reactions, changes in biomarkers of graft function and immune responses to two doses of the AS03-adjuvanted influenza A/09/H1N1 vaccine in 216 SOT recipients and in 138 controls after one dose. Antibody responses were measured by haemagglutination inhibition and confirmed by microneutralization. We calculated geometric mean titres (GMT) and seroprotection rates (GMT≥40). RESULTS Adverse reactions were fewer than in controls and graft function remained unaffected. Seroprotection was achieved by only 70.3% of SOT recipients, with significant differences between groups (lung 43.6%, heart 72.0%, kidney 83.3%, liver 83.3% and pancreas 85%), compared to 87% of controls (P<0.001). The weakest responses (seroprotection 43.5%) were elicited in lung transplant recipients. GMT remained threefold lower (115 versus 340) in SOT recipients than controls. Multivariate analyses identified increasing age, type of transplant and increasing blood levels of mycophenolate as independently associated to weaker responses. In contrast, even high blood levels of calcineurin inhibitors remained without significant influence on vaccine responses. CONCLUSIONS The squalene-based adjuvanted A/09/H1N1 vaccine was safe in SOT recipients. However, even two doses of this adjuvanted influenza vaccine did not provide adequate protection for lung transplant recipients and those with high mycophenolate blood levels. Additional prophylactic measures should, therefore, be considered for these high-risk groups.

Antibody responses to natural influenza A/H1N1/09 disease or following immunization with adjuvanted vaccines, in immunocompetent and immunocompromised children

OBJECTIVES To compare antibody responses elicited by influenza A/H1N1/09 disease and immunization with adjuvanted vaccines, in immunocompetent or immunocompromised children. STUDY DESIGN Prospective parallel cohort field study enrolling children with confirmed influenza A/H1N1/09 disease or immunized with 1 (immunocompetent) or 2 (immunocompromised) doses of influenza A/H1N1/09 squalene-based AS03- or MF59-adjuvanted vaccines. Antibody geometric mean titers (GMT) were measured by hemagglutination inhibition (HAI) and microneutralization (MN) assays 4-6 weeks after vaccination/disease. Vaccine adverse events were self-recorded in a 7-day diary. RESULTS Antibody titers were as high in 48 immunocompetent children after a single immunization (HAI and MN seroprotection rates: 98%; HAI-GMT: 395, MN-GMT: 370) as in 51 convalescent children (seroprotection rates: 98% (HAI) and 92% (MN); GMT: 350 (HAI) and 212 (MN). Twenty-seven immunocompromised children reached slightly lower seroprotection rates (HAI: 89%, MN: 85%) but similar antibody titers (HAI-GMT: 306, MN-GMT: 225) after 2 immunizations. Adverse events increased with age (P=0.01) and were more frequent with Pandemrix® than Focetria® (P=0.03). CONCLUSIONS Similarly high seroresponses may be expected in immunocompetent children after a single dose of adjuvanted vaccines as responses of convalescent children. Two vaccine doses were sufficient for most immunocompromised children. TRIAL REGISTRATION NCT0102293 and NCT01022905.

Graft-versus-host disease is the major determinant of humoral responses to the AS03-adjuvanted influenza A/09/H1N1 vaccine in allogeneic hematopoietic stem cell transplant recipients

Background Responses to influenza vaccines are poorly characterized in immunocompromised patients. The goal of this study was to assess the efficacy of the AS03-adjuvanted influenza H1N1/A/09 vaccine in allogeneic hematopoietic stem cell transplant recipients. Design and Methods We enrolled 65 patients and 138 controls in an open prospective study. Controls received one dose and patients 2 doses of the AS03-adjuvanted influenza H1N1/A/09 vaccine at a 3-week interval. Geometric mean titers and seroprotection/seroconversion rates were determined by hemagglutination inhibition before and four weeks after the last immunization. Clinical and biological markers, including immunoglobulins, CD3+, CD4+, CD8+ and naïve CD4+ T-cell counts were assessed in all patients. Results Baseline seroprotection rates were low in patients (6.6%) and controls (14.8%). After 2 doses, patients (n=57, 92.3%) achieved similar seroprotection rates (84% vs. 87%, P=0.65) and antibody titers (305 vs. 340, P=0.88) as controls (n=131, 93.9%) after one dose. In univariate analysis, transplant-to-vaccination interval less than 12 months, active graft-versus-host disease, immunosuppressive drugs, hemoglobin less than 12g/L, lymphopenia less than1G/L, IgG less than 4g/L, IgA less than 0.5g/L, IgM less than 0.5g/L and naive CD4+ T cells less than 150/μL were significantly associated with weaker responses. Multivariate analysis identified transplant-to-vaccination interval and active graft-versus-host disease as the most powerful negative predictors of antibody responses (P=0.04 and P=0.002, respectively). Vaccination was well tolerated in both cohorts. Conclusions In allogeneic hematopoietic stem cell transplant recipients, 2 doses of an adjuvanted influenza vaccine elicited comparable responses to a single dose in healthy individuals. However, vaccine responses remained poor in patients with ongoing graft-versus-host disease, supporting the need for additional strategies in this high-risk patient population. (ClinicalTrials.gov Identifier: NCT01022905)

Immunity to pneumococcal surface proteins in children with community‐acquired pneumonia: a distinct pattern of responses to pneumococcal choline‐binding protein A

The aetiological diagnosis of community-acquired pneumonia (CAP) is challenging in children, and serological markers would be useful surrogates for epidemiological studies of pneumococcal CAP. We compared the use of anti-pneumolysin (Ply) antibody alone or with four additional pneumococcal surface proteins (PSPs) (pneumococcal histidine triad D (PhtD), pneumococcal histidine triad E (PhtE), LytB, and pneumococcal choline-binding protein A (PcpA)) as serological probes in children hospitalized with CAP. Recent pneumococcal exposure (positive blood culture for Streptococcus pneumoniae, Ply(+) blood PCR finding, and PSP seroresponse) was predefined as supporting the diagnosis of presumed pneumococcal CAP (P-CAP). Twenty-three of 75 (31%) children with CAP (mean age 33.7 months) had a Ply(+) PCR finding and/or a ≥ 2-fold increase of antibodies. Adding seroresponses to four PSPs identified 12 additional patients (35/75, 45%), increasing the sensitivity of the diagnosis of P-CAP from 0.44 (Ply alone) to 0.94. Convalescent anti-Ply and anti-PhtD antibody titres were significantly higher in P-CAP than in non P-CAP patients (446 vs. 169 ELISA Units (EU)/mL, p 0.031, and 189 vs. 66 EU/mL, p 0.044), confirming recent exposure. Acute anti-PcpA titres were three-fold lower (71 vs. 286 EU/mL, p <0.001) in P-CAP children. Regression analyses confirmed a low level of acute PcpA antibodies as the only independent predictor (p 0.002) of P-CAP. Novel PSPs facilitate the demonstration of recent pneumococcal exposure in CAP children. Low anti-PcpA antibody titres at admission distinguished children with P-CAP from those with CAP with a non-pneumococcal origin.

Failure to elicit seroresponses to pneumococcal surface proteins (pneumococcal histidine triad D, pneumococcal choline-binding protein A, and serine proteinase precursor A) in children with pneumococcal bacteraemia

Pneumococcal surface proteins (PSPs) elicit antibody responses in infants and young children exposed to Streptococcus pneumoniae. These seroresponses could contribute to the aetiological diagnosis of pneumococcal disease, e.g. during the clinical development of novel PSP-based vaccines. In this study, we assessed the kinetics of antibody responses to three highly conserved and immunogenic PSPs (pneumococcal histidine triad D (PhtD), pneumococcal choline-binding protein A (PcpA), and serine proteinase precursor A (PrtA)) in 106 children (median age, 21.3 months; males, 58.5%) admitted for pneumococcal bacteraemia. Anti-PhtD, anti-PcpA and anti-PrtA antibodies were measured by ELISA, and compared in 61 pairs of acute (≤7 days) and convalescent (>14 days of admission) serum samples. Acute serum titres were similar to those observed in healthy children, and were unaffected by the acid dissociation of circulating immune complexes. Despite proven bacteraemia, seroresponses (≥2-fold increase in anti-PSP antibody concentrations) were only identified in 31 of 61 children (50.8%), directed against PrtA (n = 23, 37.7%), PcpA (n = 19, 31.1%), and PhtD (n = 16, 26.2%), or several PSPs (two PSPs, n = 13, 21.3%; three PSPs, n = 7, 11.5%). Certain seroresponses were very strong (maximal fold-increases: PhtD, 26; PcpA, 72; PrtA, 12). However, anti-PSP antibody concentrations failed to increase in the convalescent sera of 30 of 61 (49.2%) bacteraemic children, and even declined (≥2 fold) in 13 of 61 (21.3%), mostly infants aged <6 months (8/13, 61.5%), possibly through consumption of maternal antibodies. Thus, pneumococcal bacteraemia may fail to elicit antibody responses, and may even have an antibody-depleting effect in infants. This novel observation identifies an important limitation of serology-based studies for the identification of bacteraemic children.

A Prospective Study of the Factors Shaping Antibody Responses to the AS03-Adjuvanted Influenza A/H1N1 Vaccine in Cancer Outpatients

PURPOSE To identify the determinants of antibody responses to adjuvanted influenza A/H1N1/09 vaccines in a cohort of cancer outpatients. PATIENTS AND METHODS Patients with cancer and controls were enrolled in a prospective single-center field study. Two doses of AS03-adjuvanted pandemic influenza vaccine were administered to patients and one dose was administered to controls. Antibody responses were measured using hemagglutination inhibition and confirmed by microneutralization. Geometric mean titers (GMTs) and seroprotection rates (defined as GMTs ≥40) were compared. RESULTS Immunizations were safe and well tolerated in 197 cancer patients (lymphoma, 57; glioma, 26; lung or head and neck, 37; gastrointestinal, 41; breast, 36) and 138 controls. Similar seroprotection rates (82.3% versus 87%) and GMTs (336.9 versus 329.9) were achieved after two doses of adjuvanted vaccine in cancer patients and one dose in controls. Univariate analyses identified older age, prior immunization against seasonal influenza, lymphoma, CD4 count, active chemotherapy, and rituximab and steroid treatments as being associated with weaker antibody responses. However, only age and chemotherapy plus rituximab remained independent determinants of vaccine responses in multivariate analyses. CONCLUSIONS Two doses of AS03-adjuvanted influenza vaccine elicited potent antibody responses in most cancer patients despite ongoing chemotherapy, with the exception of rituximab-induced B-cell depletion. Oncology patients treated in an outpatient setting benefit from preventive vaccination against influenza with adjuvanted vaccines.

Protracted Course of Lymphocytic Choriomeningitis Virus WE Infection in Early Life: Induction but Limited Expansion of CD8+ Effector T Cells and Absence of Memory CD8+ T Cells

ABSTRACT Viral infections in human infants frequently follow a protracted course, with higher viral loads and delayed viral clearance compared to viral infections in older children. To identify the mechanisms responsible for this protracted pattern of infection, we developed an infant infection murine model using the well-characterized lymphocytic choriomeningitis virus (LCMV) WE strain in 2-week-old BALB/c mice. In contrast to adult mice, in which viral clearance occurred as expected 8 days after infection, LCMV titers persisted for several weeks after infection of infant mice. LCMV-specific effector CD8+ T cells were elicited in infant mice and fully functional on day 7 but rapidly waned and could not be recovered from day 12 onwards. We show here that this results from the failure of LCMV-specific CD8+ T cells to expand and the absence of protective LCMV-specific memory CD8+ T cells. Under these early life conditions, viral control and clearance are eventually achieved only through LCMV-specific B cells that contribute to protect infant mice from early death or chronic infection.

A dose-dependent plasma signature of the safety and immunogenicity of the rVSV-Ebola vaccine in Europe and Africa

A specific plasma signature reveals the critical role of monocytes in the VSV-vectored Ebola vaccine immunogenicity and safety. Monocytes make their mark in Ebola vaccination A VSV-vectored Ebola vaccine was used in Guinea during the recent outbreak and has now been shown to be incredibly effective in preventing infection. However, the vaccine itself did cause somewhat severe reactions in some subjects, including fever and arthritis. Huttner et al. examined longitudinal plasma samples from vaccine recipients in Europe and Africa to identify a signature of the immune response and adverse events. The signature of monocyte-derived cytokines held true in both cohorts, suggesting that it could also be applied to other vaccine trials to determine immunogenicity and reactogenicity. The 2014–2015 Ebola epidemic affected several African countries, claiming more than 11,000 lives and leaving thousands with ongoing sequelae. Safe and effective vaccines could prevent or limit future outbreaks. The recombinant vesicular stomatitis virus–vectored Zaire Ebola (rVSV-ZEBOV) vaccine has shown marked immunogenicity and efficacy in humans but is reactogenic at higher doses. To understand its effects, we examined plasma samples from 115 healthy volunteers from Geneva who received low-dose (LD) or high-dose (HD) vaccine or placebo. Fifteen plasma chemokines/cytokines were assessed at baseline and on days 1, 2 to 3, and 7 after injection. Significant increases in monocyte-mediated MCP-1/CCL2, MIP-1β/CCL4, IL-6, TNF-α, IL-1Ra, and IL-10 occurred on day 1. A signature explaining 68% of cytokine/chemokine vaccine-response variability was identified. Its score was higher in HD versus LD vaccinees and was associated positively with vaccine viremia and negatively with cytopenia. It was higher in vaccinees with injection-site pain, fever, myalgia, chills, and headache; higher scores reflected increasing severity. In contrast, HD vaccinees who subsequently developed arthritis had lower day 1 scores than other HD vaccinees. Vaccine dose did not influence the signature despite its influence on specific outcomes. The Geneva-derived signature associated strongly (ρ = 0.97) with that of a cohort of 75 vaccinees from a parallel trial in Lambaréné, Gabon. Its score in Geneva HD vaccinees with subsequent arthritis was significantly lower than that in Lambaréné HD vaccinees, none of whom experienced arthritis. This signature, which reveals monocytes’ critical role in rVSV-ZEBOV immunogenicity and safety across doses and continents, should prove useful in assessments of other vaccines.