Procedures
diarrhoea, nausea, myalgia, fever, fatigue, erythema, pain, headache, tick-borne encephalitis, dengue virus particle DENV1-4, or NS1 and, tenderness, CHUV
VIRUS, ADVERSE EVENTS, DENGUE, ERYTHEMA, TICK-BORNE ENCEPHALITIS, HAND SWELLING, IMMUN, DENGUE
Dengue peptides in PepGNP-Dengue were selected using an immunoproteomics approach, validated in DENV peptides and GNPs were manufactured according to current good manufacturing practices by CSBio (USA) and Ardena-Oss (Netherlands), respectively. The final drug product (PepGNP-Dengue and vehicle-GNP) was lyophilized and packed by Symbiosis Pharmaceutical Services Limited (UK) and stored at −20 °C. CHUV pharmacists reconstituted the final freeze-dried powder product with water for injection for administration.Two doses (0.05 ml each) were administered intradermally 21 days apart in the deltoid region of the upper arm using the Nanopass MicronJet600 microneedle. A second injection was given to promote the generation of CD8+ T cells with innate and help-independent recall capacities, cytotoxic T effector programme and increased tissue invasiveness (i.e., tissue-resident T memory [TRM] cells).Reactogenicity and safety were assessed 1 h post-injection and at the above-mentioned time points. Solicited local (pain, tenderness, erythema, and swelling) and systemic reactions (fever, headache, nausea, diarrhoea, fatigue, myalgia) occurring up to 7 and 14 days after each injection, respectively, were recorded by participants in diary cards. Participants were given a ruler to measure the size of local erythema/swelling and a thermometer to record their temperature daily. The investigators assessed unsolicited adverse events (AEs) and adverse events of special interest (AESIs) (Immunological analyses were performed on days 0, 21, 35, 90 and 180. Humoral immune responses against dengue virus particle DENV1-4, or NS1 and tick-borne encephalitis virus (TBE) were measured using commercial ELISA kits (anti-dengue virus types 1-4 IgG, # EI 266a-9601-1 G; anti-dengue virus NS1 type 1-4 IgG, # EI 266a-9601-2 G; Euro Immun, Lübeck, DE; FSME/TBE ELISA IgG/IgM, # EC117.00, Virotech Diagnostics, Rüsselheim, DE; Circulating CD8+ T cell responses induced by PepGNP-Dengue were determined by cytometry: i) by measurement of activation-induced markers (AIM) at baseline and days 21, 35, 90, and 180 and ii) using HLA class I dextramers at baseline, day 35 and 180. Class I HLA typing was performed on whole blood by RT-PCR, using the kit LinkSeq HLA ABCDRDQDP SABR (Linkage Bioscience).For AIM, the frequency of CD8+ cells expressing the activation co-markers CD107a+CD25+ and/or CD137+CD69+ was measured upon stimulation of peripheral blood mononuclear cells (PBMCs) with DENV peptides or PepGNP-Dengue, adapted from published methods.For dextramer, we used eight dengue (four HLA-A∗0201, three B∗0702, and one A∗0301) and control dextramers (MHC Dextramer®, Immudex, DK) described in 