Jack Heptinstall

MRNA technology might accelerate development of an urgently needed preventive human immunodeficiency virus (HIV) vaccine. We evaluated the safety and immunogenicity of three mRNA-encoded envelope trimers, including two doses of soluble and membrane-anchored forms, in a randomized, open-label, phase 1 clinical trial. Vaccines were generally well tolerated, although 6.5% (7 of 108) of participants developed urticaria, a higher proportion than seen with other mRNA vaccines. mRNA-encoded trimers induced strong envelope-specific B and T cell responses. Immunization with membrane-anchored trimers, intended to obscure epitopes at the trimer base targeted by nonneutralizing antibodies, reduced the frequency of base-binding serum antibodies in comparison with soluble trimers. Three immunizations elicited autologous tier 2 serum neutralizing antibodies in 80% of vaccinees receiving the membrane-anchored trimers, in contrast to only 4% receiving the soluble trimer. Thus, with demonstration of more favorable safety, mRNA-encoded membrane-anchored HIV envelope trimers represent a promising platform for HIV vaccine clinical development.

Cutaneous mycobacterial infections cause substantial morbidity and are challenging to diagnose and treat. An improved understanding of the dermal immune response to mycobacteria may inspire new therapeutic approaches. We conducted a controlled human infection study with 10 participants who received 2 × 106 CFUs of Mycobacterium bovis bacillus Calmette-Guérin (Tice strain) intradermally and were randomized to receive isoniazid or no treatment. Peripheral blood was collected at multiple time points for flow cytometry, bulk RNA sequencing (RNA-seq), and serum Ab assessments. Systemic immune responses were detected as early as 8 d postchallenge in this M. bovis bacillus Calmette-Guérin–naive population. Injection-site skin biopsies were performed at days 3 and 15 postchallenge and underwent immune profiling using mass cytometry and single-cell RNA-seq, as well as quantitative assessments of bacterial viability and burden. Molecular viability testing and standard culture results correlated well, although no differences were observed between treatment arms. Single-cell RNA-seq revealed various immune and nonimmune cell types in the skin, and communication between them was inferred by ligand-receptor gene expression. Day 3 communication was predominantly directed toward monocytes from keratinocyte, muscle, epithelial, and endothelial cells, largely via the migration inhibitory factor pathway and HLA-E–KLRK1 interaction. At day 15, communication was more balanced between cell types. These data reveal the potential role of nonimmune cells in the dermal immune response to mycobacteria and the utility of human challenge studies to augment our understanding of mycobacterial infections.

BACKGROUND: An HIV-1 DNA vaccine composed of 7 highly conserved, structurally important elements (conserved elements, CE) of p24 ^Gag was tested in a phase I randomized, double-blind clinical trial (HVTN 119, NCT03181789) in people without HIV. DNA vaccination of CE prime/CE+p55 ^Gag boost was compared with p55 ^Gag . METHODS: Two groups ( n = 25) received 4 DNA vaccinations (CE/CE+p55 ^Gag or p55 ^Gag ) by intramuscular injection/electroporation, including IL-12 DNA adjuvant. The placebo group ( n = 6) received saline. Participants were followed for safety and tolerability. Immunogenicity was assessed for T cell and antibody responses. RESULTS: Both regimens were safe and generally well tolerated. The p24CE vaccine was immunogenic and significantly boosted by CE+p55 ^Gag (64% CD4 ⁺ , P = 0.037; 42% CD8 ⁺ , P = 0.004). CE+p55 ^Gag induced responses to 5 of 7 CE, compared with only 2 CE by p55 ^Gag DNA, with a higher response to CE5 in 30% of individuals ( P = 0.006). CE+p55 ^Gag induced significantly higher CD4 ⁺ CE T cell breadth (0.68 vs. 0.22 CE; P = 0.029) and a strong trend for overall T cell breadth (1.14 vs. 0.52 CE; P = 0.051). Both groups developed high cellular and humoral responses. p24CE vaccine–induced CD4 ⁺ CE T cell responses correlated ( P = 0.007) with p24 ^Gag antibody responses. CONCLUSION: The CE/CE+p55 ^Gag DNA vaccine induced T cell responses to conserved regions in p24 ^Gag , increasing breadth and epitope recognition throughout p55 ^Gag compared with p55 ^Gag DNA. Vaccines focusing immune responses by priming responses to highly conserved regions could be part of a comprehensive HIV vaccine strategy. TRIAL REGISTRATION: Clinical Trials.gov NCT03181789 FUNDING: HVTN, NIAID/NIH

Background: An effective vaccine is required to end the HIV pandemic. We evaluated the safety and immunogenicity of a DNA (DNA-HIV-PT123) vaccine with low- or high-dose bivalent (TV1.C and 1086.C glycoprotein 120) subtype C envelope protein combinations, adjuvanted with MF59 or AS01_B. Methods: HIV Vaccine Trials Network (HVTN)108 was a randomized, placebo-controlled, double-blind, phase 1/2a trial conducted in the United States and South Africa. HIV-negative adults were randomly assigned to 1 of 7 intervention arms or placebo to assess DNA prime with DNA/protein/adjuvant boosts, DNA/protein/adjuvant co-administration, and low-dose protein/adjuvant regimens. HVTN111 trial participants who received an identical regimen were also included. Outcomes included safety and immunogenicity 2 weeks and 6 months after final vaccination. Results: From June 2016 to July 2018, 400 participants were enrolled (N = 334 HVTN108, N = 66 HVTN111); 370 received vaccine and 30 received placebo. There were 48 grade 3 and 3 grade 4 reactogenicity events among 39/400 (9.8%) participants, and 32 mild/moderate-related adverse events in 23/400 (5.8%) participants. All intervention groups demonstrated high IgG response rates (>89%) and high magnitudes to HIV-1 Env gp120 and gp140 proteins; response rates for AS01_B-adjuvanted groups approached 100%. V1V2 IgG magnitude, Fc-mediated functions, IgG3 Env response rates, and CD4⁺ T-cell response magnitudes and rates were higher in the AS01_B-adjuvanted groups. The AS01_B-adjuvanted low-dose protein elicited greater IgG responses than the higher protein dose. Conclusions: The vaccine regimens were generally well tolerated. Co-administration of DNA with AS01_B-adjuvanted bivalent Env gp120 elicited the strongest humoral responses; AS01_B-adjuvanted regimens elicited stronger CD4⁺ T-cell responses, justifying further evaluation. ClinicalTrials.gov registration: NCT02915016, registered 26 September 2016.

Background: Adjuvants are widely used to enhance and/or direct vaccine-induced immune responses yet rarely evaluated head-to-head. Our trial directly compared immune responses elicited by MF59 versus alum adjuvants in the RV144-like HIV vaccine regimen modified for the Southern African region. The RV144 trial of a recombinant canarypox vaccine vector expressing HIVenvsubtype B (ALVAC-HIV) prime followed by ALVAC-HIV plus a bivalent gp120 protein vaccine boost adjuvanted with alum is the only trial to have shown modest HIV vaccine efficacy. Data generated after RV144 suggested that use of MF59 adjuvant might allow lower protein doses to be used while maintaining robust immune responses. We evaluated safety and immunogenicity of an HIV recombinant canarypox vaccine vector expressing HIVenvsubtype C (ALVAC-HIV) prime followed by ALVAC-HIV plus a bivalent gp120 protein vaccine boost (gp120) adjuvanted with alum (ALVAC-HIV+gp120/alum) or MF59 (ALVAC-HIV+gp120/MF59) or unadjuvanted (ALVAC-HIV+gp120/no-adjuvant) and a regimen where ALVAC-HIV+gp120 adjuvanted with MF59 was used for the prime and boost (ALVAC-HIV+gp120/MF59 coadministration).Methods and findings: Between June 19, 2017 and June 14, 2018, 132 healthy adults without HIV in South Africa, Zimbabwe, and Mozambique were randomized to receive intramuscularly: (1) 2 priming doses of ALVAC-HIV (months 0 and 1) followed by 3 booster doses of ALVAC-HIV+gp120/MF59 (months 3, 6, and 12),n= 36; (2) 2 priming doses of ALVAC-HIV (months 0 and 1) followed by 3 booster doses of ALVAC-HIV+gp120/alum (months 3, 6, and 12),n= 36; (3) 4 doses of ALVAC-HIV+gp120/MF59 coadministered (months 0, 1, 6, and 12),n= 36; or (4) 2 priming doses of ALVAC-HIV (months 0 and 1) followed by 3 booster doses of ALVAC-HIV+gp120/no adjuvant (months 3, 6, and 12),n= 24. Primary outcomes were safety and occurrence and mean fluorescence intensity (MFI) of vaccine-induced gp120-specific IgG and IgA binding antibodies at month 6.5.All vaccinations were safe and well-tolerated; increased alanine aminotransferase was the most frequent related adverse event, occurring in 2 (1.5%) participants (1 severe, 1 mild). At month 6.5, vaccine-specific gp120 IgG binding antibodies were detected in 100% of vaccinees for all 4 vaccine groups. No significant differences were seen in the occurrence and net MFI of vaccine-specific IgA responses between the ALVAC-HIV+gp120/MF59-prime-boost and ALVAC-HIV+gp120/alum-prime-boost groups or between the ALVAC-HIV+gp120/MF59-prime-boost and ALVAC-HIV+gp120/MF59 coadministration groups. Limitations were the relatively small sample size per group and lack of evaluation of higher gp120 doses.Conclusions: Although MF59 was expected to enhance immune responses, alum induced similar responses to MF59, suggesting that the choice between these adjuvants may not be critical for the ALVAC+gp120 regimen.Trial registration: HVTN 107 was registered with the South African National Clinical Trials Registry (DOH-27-0715-4894) andClinicalTrials.gov(NCT03284710).

People living with HIV-1 (PLWH) exhibit more rapid antibody decline following routine immunization and elevated baseline chronic inflammation than people without HIV-1 (PWOH), indicating potential for diminished humoral immunity during SARS-CoV-2 infection. Conflicting reports have emerged on the ability of PLWH to maintain humoral protection against SARS-CoV-2 coinfection during convalescence. It is unknown whether peak COVID-19 severity, along with HIV-1 infection status, associates with the quality and quantity of humoral immunity following recovery. Using a cross-sectional observational cohort from the United States and Peru, adults were enrolled 1–10 weeks after SARS-CoV-2 infection diagnosis or symptom resolution. Serum antibodies were analyzed for SARS-CoV-2–specific response rates, binding magnitudes, ACE2 receptor blocking, and antibody-dependent cellular phagocytosis. Overall, (a) PLWH exhibited a trend toward decreased magnitude of SARS-CoV-2–specific antibodies, despite modestly increased overall response rates when compared with PWOH; (b) PLWH recovered from symptomatic outpatient COVID-19 had comparatively diminished immune responses; and (c) PLWH lacked a corresponding increase in SARS-CoV-2 antibodies with increased COVID-19 severity when asymptomatic versus symptomatic outpatient disease was compared.

Background: The phase 2b proof-of-concept Antibody Mediated Prevention (AMP) trials showed that VRC01, a broadly neutralizing antibody (bnAb), prevented acquisition of HIV-1 sensitive to VRC01. To inform future study design and dosing regimen selection of candidate bnAbs, we investigated the association of VRC01 serum concentration with HIV-1 acquisition using AMP trial data. Methods: The case-control sample included 107 VRC01 recipients who acquired HIV-1 (cases) and 82 VRC01 recipients who remained without HIV-1 (non-cases) during the study. We measured VRC01 serum concentrations with a qualified pharmacokinetic (PK) Binding Antibody Multiplex Assay. We employed nonlinear mixed effects PK modeling to estimate daily-grid VRC01 concentrations for both case and non-cases. Cox regression models were used to assess the association of the current value of VRC01 concentration and baseline body weight with the hazard of HIV-1 acquisition. We also compared fixed dosing vs. body weight-based dosing by a simulation of 1000 AMP-like trials. Findings: Estimated VRC01 concentrations in non-cases were higher than those in cases. Body weight was inversely associated with HIV-1 acquisition among both placebo and VRC01 recipients but did not modify the prevention efficacy of VRC01. VRC01 concentration remained inversely correlated with HIV-1 acquisition risk after accounting for body weight. Fixed dosing had comparable overall predicted prevention efficacy as weight-based dosing in simulation studies. Interpretation: These findings suggest that bnAb serum concentration could be a useful marker for dosing regimen selection, and operationally efficient fixed dosing regimens could be effective on a population-level for future trials of HIV-1 bnAbs. Funding: was provided by the National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID) (UM1 AI068614, to the HIV Vaccine Trials Network [HVTN]; UM1 AI068635, to the HVTN Statistical Data and Management Center [SDMC], Fred Hutchinson Cancer Center [FHCC]; UM1 AI068618, to HVTN Laboratory Center, FHCC; UM1 AI068619, to the HPTN Leadership and Operations Center; UM1 AI068613, to the HIV Prevention Trials Network [HPTN] Laboratory Center; UM1 AI068617, to the HPTN SDMC; and P30 AI027757, to the Center for AIDS Research, Duke University (AI P30 AI064518) and University of Washington (P30 AI027757). Declaration of Interest: GT is supported by a grant from the Bill & Melinda Gates Foundation outside of the submitted work. All other authors declare no competing interests. Ethical Approval: These analyses were approved by the Duke University Health System Institutional Review Board (Duke University) (protocol #Pro00093087). For the National Institute for Communicable Diseases the work was approved by the University of the Witwatersrand Human Research Ethics Committee (protocol #M201105). All participants in the AMP trials provided written informed consent

DNA plasmids promise a pragmatic alternative to viral vectors for prime-boost HIV-1 vaccines. We evaluated DNA plasmid versus canarypox virus (ALVAC) primes in 2 randomized, double-blind, placebo-controlled trials in southern Africa with harmonized trial designs. HIV Vaccine Trials Network (HVTN) 111 tested DNA plasmid prime by needle or needleless injection device (Biojector) and DNA plasmid plus gp120 protein plus MF59 adjuvant boost. HVTN 100 tested ALVAC prime and ALVAC plus gp120 protein plus MF59 adjuvant boost (same protein/adjuvant as HVTN 111) by needle. The primary endpoints for this analysis were binding antibody (bAb) responses to HIV antigens (gp120 from strains ZM96, 1086, and TV1; variable 1 and 2 [V1V2] regions of gp120 from strains TV1, 1086, and B.CaseA, as 1086 V1V2 and B.CaseA were correlates of risk in the RV144 efficacy trial), neutralizing antibody (nAb) responses to pseudoviruses TV1c8.2 and MW925.26, and cellular responses to vaccine-matched antigens (envelope [Env] from strains ZM96, 1086, and TV1; and Gag from strains LAI and ZM96) at month 6.5, two weeks after the fourth vaccination. Per-protocol cohorts included vaccine recipients from HVTN 100 (n = 186, 60% male, median age 23 years) enrolled between February 9, 2015, and May 26, 2015 and from HVTN 111 (n = 56, 48% male, median age 24 years) enrolled between June 21, 2016, and July 13, 2017. IgG bAb response rates were 100% to 3 Env gp120 antigens in both trials. Response rates to V1V2 were lower and similar in both trials except to vaccine-matched 1086 V1V2, with rates significantly higher for the DNA-primed regimen than the ALVAC-primed regimen: 96.6% versus 72.7% (difference = 23.9%, 95% CI 15.6%–32.2%, p < 0.001). Among positive responders, bAb net mean fluorescence intensity (MFI) was significantly higher with the DNA-primed regimen than ALVAC-primed for 1086 V1V2 (geometric mean [GM] 2,833.3 versus 1,200.9; ratio = 2.36, 95% CI 1.42–3.92, p < 0.001) and B.CaseA V1V2 (GM 2314.0 versus 744.6, ratio = 3.11, 95% CI 1.51–6.38, p = 0.002). nAb response rates were >98% in both trials, with significantly higher 50% inhibitory dilution (ID₅₀) among DNA-primed positive responders (n = 53) versus ALVAC-primed (n = 182) to tier 1A MW965.26 (GM 577.7 versus 265.7, ratio = 2.17, 95% CI 1.67–2.83, p < 0.001) and to TV1c8.2 (GM 187.3 versus 100.4, ratio = 1.87, 95% CI 1.48–2.35, p < 0.001). CD4+ T-cell response rates were significantly higher with DNA plasmid prime via Biojector than ALVAC prime (91.4% versus 52.8%, difference = 38.6%, 95% CI 20.5%–56.6%, p < 0.001 for ZM96.C; 88.0% versus 43.1%, difference = 44.9%, 95% CI 26.7%–63.1%, p < 0.001 for 1086.C; 55.5% versus 2.2%, difference = 53.3%, 95% CI 23.9%–82.7%, p < 0.001 for Gag LAI/ZM96). The study’s main limitations include the nonrandomized comparison of vaccines from 2 different trials, the lack of data on immune responses to other non–vaccine-matched antigens, and the uncertain clinical significance of the observed immunological effects. In this study, we found that further investigation of DNA/protein regimens is warranted given enhanced immunogenicity to the V1V2 correlates of decreased HIV-1 acquisition risk identified in RV144, the only HIV vaccine trial to date to show any efficacy.