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BNT162b2, a lipid nanoparticle (LNP) formulated nucleoside-modified messenger RNA (mRNA) encoding the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein (S) stabilized in the prefusion conformation, has demonstrated 95% efficacy to prevent coronavirus disease 2019 (COVID-19). Recently, we reported preliminary BNT162b2 safety and antibody response data from an ongoing placebo-controlled, observer-blinded phase 1/2 vaccine trial1. We present here antibody and T cell responses from a second, non-randomized open-label phase 1/2 trial in healthy adults, 19-55 years of age, after BNT162b2 prime/boost vaccination at 1 to 30 µg dose levels. BNT162b2 elicited strong antibody responses, with S-binding IgG concentrations above those in a COVID-19 human convalescent sample (HCS) panel. Day 29 (7 days post-boost) SARS-CoV-2 serum 50% neutralising geometric mean titers were 0.3-fold (1 µg) to 3.3-fold (30 µg) those of the HCS panel. The BNT162b2-elicited sera neutralised pseudoviruses with diverse SARS-CoV-2 S variants. Concurrently, in most participants, S-specific CD8+ and T helper type 1 (TH1) CD4+ T cells had expanded, with a high fraction producing interferon-γ (IFNγ). Using peptide MHC multimers, the epitopes recognised by several BNT162b2-induced CD8+ T cells when presented on frequent MHC alleles were identified. CD8+ T cells were shown to be of the early-differentiated effector-memory phenotype, with single specificities reaching 0.01-3% of circulating CD8+ T cells. In summary, vaccination with BNT162b2 at well tolerated doses elicits a combined adaptive humoral and cellular immune response, which together may contribute to protection against COVID-19.

An effective vaccine is needed to halt the spread of the SARS-CoV-2 pandemic. Recently, we reported safety, tolerability and antibody response data from an ongoing placebo-controlled, observer-blinded phase 1/2 COVID-19 vaccine trial with BNT162b1, a lipid nanoparticle (LNP) formulated nucleoside-modified messenger RNA encoding the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. Here we present antibody and T cell responses after BNT162b1 vaccination from a second, non-randomized open-label phase 1/2 trial in healthy adults, 18-55 years of age. Two doses of 1 to 50 μg of BNT162b1 elicited robust CD4+ and CD8+ T cell responses and strong antibody responses, with RBD-binding IgG concentrations clearly above those in a COVID-19 convalescent human serum panel (HCS). Day 43 SARS-CoV-2 serum neutralising geometric mean titers were 0.7-fold (1 μg) to 3.5-fold (50 μg) those of HCS. Immune sera broadly neutralised pseudoviruses with diverse SARS-CoV-2 spike variants. Most participants had TH1 skewed T cell immune responses with RBD-specific CD8+ and CD4+ T cell expansion. Interferon (IFN)γ was produced by a high fraction of RBD-specific CD8+ and CD4+ T cells. The robust RBD-specific antibody, T-cell and favourable cytokine responses induced by the BNT162b1 mRNA vaccine suggest multiple beneficial mechanisms with potential to protect against COVID-19.

PurposeIntravenous (IVIG) and subcutaneous (SCIG) immunoglobulin infusions are widely used for the treatment of patients with primary immunodeficiency (PID) worldwide. This prospective, multicenter, open-label, single-arm Phase III study evaluated the efficacy, tolerability, and safety of IgPro20 (Hizentra®; L-proline–stabilized 20 % human SCIG) in adult and pediatric Japanese patients with PID.MethodsPatients received three IVIG infusions at 3–4-week intervals followed by a dose-equivalent switch to weekly SCIG infusions. A 12-week wash-in/wash-out period was followed by a 12-week SCIG efficacy period. The primary efficacy endpoint was the comparison of total serum IgG trough levels during the IVIG and SCIG efficacy periods by calculating the geometric mean ratio (GMR).ResultsThe GMR of IgG trough levels on SCIG versus IVIG was 1.09 (2-sided 90 % confidence interval: 1.06–1.13). No serious bacterial infections were reported. Eleven patients (52.4 %) had infectious episodes with an overall rate of 2.98 infections/patient/year; 7 patients (33.3 %) missed school/work/daycare due to infection (3.48 days/patient/year). Sixteen patients (76.2 %) were treated with antibiotics for an adverse event (AE; 47.6 %) or prophylaxis (23.8 %), resulting in 167.42 days/patient/year of antibiotic use. During SCIG treatment, 24 patients (96.0 %) had 269 AEs (0.461 AEs per/infusion) including local reactions as the most common AE (20 patients, 80.0 %). Local tolerability of IgPro20 was assessed as “very good” or “good” after 85.4 % of SCIG infusions. One patient (4.0 %) experienced a serious AE of moderate severity (bacterial infection) that was considered unrelated to study medication.ConclusionIgPro20 was effective and well tolerated in Japanese patients with PID.