Innate Responses to the Former COVID-19 Vaccine Candidate CVnCoV and Their Relation to Reactogenicity and Adaptive Immunogenicity

Vaccines are highly effective at preventing severe coronavirus disease (COVID-19). With mRNA vaccines, further research is needed to understand the association between immunogenicity and reactogenicity, which is defined as the physical manifestation of an inflammatory response to a vaccination. This study analyzed the immune response and reactogenicity in humans, post immunization, to the former SARS-CoV-2 mRNA investigational vaccine CVnCoV (CV-NCOV-001 and CV-NCOV-002 clinical trials). Immunogenicity was investigated using whole-blood RNA sequencing, serum cytokine levels, and SARS-CoV-2-specific antibodies. The T cell responses in peripheral blood were assessed using intracellular cytokine staining (ICS) and high-dimensional profiling in conjunction with SARS-CoV-2 antigen-specificity testing via mass cytometry. Reactogenicity was graded after participants' first and second doses of CVnCoV using vaccine-related solicited adverse events (AEs). Finally, a Spearman correlation was performed between reactogenicity, humoral immunity, and serum cytokine levels to assess the relationship between reactogenicity and immunogenicity post CVnCoV vaccination. Our findings showed that the gene sets related to innate and inflammatory immune responses were upregulated one day post CVnCoV vaccination, while the gene sets related to adaptive immunity were upregulated predominantly one week after the second dose. The serum levels of IFNα, IFNγ, IP-10, CXCL11, IL-10, and MCP-1 increased transiently, peaking one day post vaccination. CD4+ T cells were induced in all vaccinated participants and low frequencies of CD8+ T cells were detected by ex vivo ICS. Using mass cytometry, SARS-CoV-2 spike-specific CD8+ T cells were induced and were characterized as having an activated effector memory phenotype. Overall, the results demonstrated a positive correlation between vaccine-induced systemic cytokines, reactogenicity, and adaptive immunity, highlighting the importance of the balance between the induction of innate immunity to achieve vaccine efficacy and ensuring low reactogenicity.

Corrigendum to "Safety and immunogenicity of mRNA-LNP COVID-19 vaccine CVnCoV in Latin American adults: A phase 2 randomized study" [Vaccine: X 11 (2022) 100189]

[This corrects the article DOI: 10.1016/j.jvacx.2022.100189.].

Safety and immunogenicity of mRNA-LNP COVID-19 vaccine CVnCoV in Latin American adults: a phase 2 randomized study

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Two 12 µg CVnCoV doses are immunogenic against S-protein in adults.

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Immune responses were lower in > 60 year-olds than 18–60 year-olds.

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Distinct neutralizing antibody and CD4 + T cell responses to S-protein were induced.

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Booster doses increased responses to S-protein showing immune memory was induced.

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Three 12 µg doses are well tolerated with mainly mild to moderate adverse events.

Background

The COVID-19 vaccine candidate CVnCoV comprises sequence-optimized mRNA encoding SARS-CoV-2 S-protein encapsulated in lipid nanoparticles. In this phase 2a study, we assessed reactogenicity and immunogenicity of two or three doses in younger and older adults.

Methods

Younger (18–60 years) and older (>60 years) adults were enrolled in two sites in Panama and Peru to receive either 6 or 12 µg doses of CVnCoV or licensed control vaccines 28 days apart; subsets received a 12 µg booster dose on Day 57 or Day 180. Solicited adverse events (AE) were reported for 7 days and unsolicited AEs for 4 weeks after each vaccination, and serious AEs (SAE) throughout the study. Humoral immunogenicity was measured as neutralizing and receptor binding domain (RBD) IgG antibodies and cellular immunogenicity was assessed as CD4+/CD8 + T cell responses.

Results

A total of 668 participants were vaccinated (332 aged 18–60 years and 336 aged > 60 years) including 75 who received homologous booster doses. Vaccination was well tolerated with no vaccine-related SAEs. Solicited and unsolicited AEs were mainly mild to moderate and resolved spontaneously. Both age groups demonstrated robust immune responses as neutralizing antibodies or RBD-binding IgG, after two doses, with lower titers in the older age group than the younger adults. Neither group achieved levels observed in human convalescent sera (HCS), but did equal or surpass HCS levels following homologous booster doses. Following CVnCoV vaccination, robust SARS-CoV-2 S-protein-specific CD4 + T-cell responses were observed in both age groups with CD8 + T-cell responses in some individuals, consistent with observations in convalescing COVID-19 patients after natural infection.

Conclusions

We confirmed that two 12 µg doses of CVnCoV had an acceptable safety profile, and induced robust immune responses. Marked humoral immune responses to homologous boosters suggest two doses had induced immune memory.

Efficacy and safety of the CVnCoV SARS-CoV-2 mRNA vaccine candidate in ten countries in Europe and Latin America (HERALD): a randomised, observer-blinded, placebo-controlled, phase 2b/3 trial

BACKGROUND

Additional safe and efficacious vaccines are needed to control the COVID-19 pandemic. We aimed to analyse the efficacy and safety of the CVnCoV SARS-CoV-2 mRNA vaccine candidate.

METHODS

HERALD is a randomised, observer-blinded, placebo-controlled, phase 2b/3 clinical trial conducted in 47 centres in ten countries in Europe and Latin America. By use of an interactive web response system and stratification by country and age group (18-60 years and ≥61 years), adults with no history of virologically confirmed COVID-19 were randomly assigned (1:1) to receive intramuscularly either two 0·6 mL doses of CVnCoV containing 12 μg of mRNA or two 0·6 mL doses of 0·9% NaCl (placebo) on days 1 and 29. The primary efficacy endpoint was the occurrence of a first episode of virologically confirmed symptomatic COVID-19 of any severity and caused by any strain from 15 days after the second dose. For the primary endpoint, the trial was considered successful if the lower limit of the CI was greater than 30%. Key secondary endpoints were the occurrence of a first episode of virologically confirmed moderate-to-severe COVID-19, severe COVID-19, and COVID-19 of any severity by age group. Primary safety outcomes were solicited local and systemic adverse events within 7 days after each dose and unsolicited adverse events within 28 days after each dose in phase 2b participants, and serious adverse events and adverse events of special interest up to 1 year after the second dose in phase 2b and phase 3 participants. Here, we report data up to June 18, 2021. The study is registered at ClinicalTrials.gov, NCT04652102, and EudraCT, 2020-003998-22, and is ongoing.

FINDINGS

Between Dec 11, 2020, and April 12, 2021, 39 680 participants were enrolled and randomly assigned to receive either CVnCoV (n=19 846) or placebo (n=19 834), of whom 19 783 received at least one dose of CVnCoV and 19 746 received at least one dose of placebo. After a mean observation period of 48·2 days (SE 0·2), 83 cases of COVID-19 occurred in the CVnCoV group (n=12 851) in 1735·29 person-years and 145 cases occurred in the placebo group (n=12 211) in 1569·87 person-years, resulting in an overall vaccine efficacy against symptomatic COVID-19 of 48·2% (95·826% CI 31·0-61·4; p=0·016). Vaccine efficacy against moderate-to-severe COVID-19 was 70·7% (95% CI 42·5-86·1; CVnCoV 12 cases in 1735·29 person-years, placebo 37 cases in 1569·87 person-years). In participants aged 18-60 years, vaccine efficacy against symptomatic disease was 52·5% (95% CI 36·2-64·8; CVnCoV 71 cases in 1591·47 person-years, placebo, 136 cases in 1449·23 person-years). Too few cases occurred in participants aged 61 years or older (CVnCoV 12, placebo nine) to allow meaningful assessment of vaccine efficacy. Solicited adverse events, which were mostly systemic, were more common in CVnCoV recipients (1933 [96·5%] of 2003) than in placebo recipients (1344 [67·9%] of 1978), with 542 (27·1%) CVnCoV recipients and 61 (3·1%) placebo recipients reporting grade 3 solicited adverse events. The most frequently reported local reaction after any dose in the CVnCoV group was injection-site pain (1678 [83·6%] of 2007), with 22 grade 3 reactions, and the most frequently reported systematic reactions were fatigue (1603 [80·0%] of 2003) and headache (1541 [76·9%] of 2003). 82 (0·4%) of 19 783 CVnCoV recipients reported 100 serious adverse events and 66 (0·3%) of 19 746 placebo recipients reported 76 serious adverse events. Eight serious adverse events in five CVnCoV recipients and two serious adverse events in two placebo recipients were considered vaccination-related. None of the fatal serious adverse events reported (eight in the CVnCoV group and six in the placebo group) were considered to be related to study vaccination. Adverse events of special interest were reported for 38 (0·2%) participants in the CVnCoV group and 31 (0·2%) participants in the placebo group. These events were considered to be related to the trial vaccine for 14 (<0·1%) participants in the CVnCoV group and for five (<0·1%) participants in the placebo group.

INTERPRETATION

CVnCoV was efficacious in the prevention of COVID-19 of any severity and had an acceptable safety profile. Taking into account the changing environment, including the emergence of SARS-CoV-2 variants, and timelines for further development, the decision has been made to cease activities on the CVnCoV candidate and to focus efforts on the development of next-generation vaccine candidates.

FUNDING

German Federal Ministry of Education and Research and CureVac.

473 Immune profiling of patients with advanced solid tumors treated with intratumorally administered CV8102 as a single-agent or in combination with anti-PD-1 antibodies in phase I clinical trial

Background

CV8102 is a non-coding, non-capped RNA complexed with a carrier peptide activating the innate (via TLR7/8, RIG-I) and adaptive immune system.1 2 An ongoing phase I trial is investigating the intratumoral (i.t.) administration of CV8102 in patients with advanced cutaneous melanoma (cMEL), squamous cell carcinoma of the skin (cSCC) or head and neck (hnSCC) and adenoid cystic carcinoma (ACC), either as a single agent or in combination with systemic anti-PD-1 antibodies. Preliminary immune profiling results will be reported.

Methods

An open-label, cohort-based, dose escalation and expansion study in patients with advanced cMEL, cSCC, hnSCC or ACC is ongoing investigating CV8102 i.t. as single agent and in combination with anti-PD-1 antibodies. Eight i.t. injections of CV8102 were administered over a 12 week period with optional continuing treatment in case of clinical benefit. In the initial dose escalation part, the recommended phase II dose for subsequent cohort expansion was defined. Blood samples for immune cell phenotyping, RNA sequencing (RNAseq) and serum cytokine/chemokine analysis were collected at baseline and multiple time points during the treatment period. For characterization of the tumor microenvironment (TME), optional core needle biopsies of injected and/or non-injected lesions were taken before, during and after treatment. Changes on various tumor-infiltrating immune cells were assessed by multiplex immunofluorescence (MultiOmyx < sup >TM</sup > ) and immune-related gene expression profiling using nCounter® Pan Cancer IO360 < sup >TM</sup > panel (NanoString).

Results

During the dose escalation part, 33 patients received CV8102 (dose range of 25–900 µg) as single agent and 25 patients received CV8102 in combination with an anti-PD-1 antibody. A dose of 600 µg was selected as recommended phase II dose. Serum cytokine/chemokine and blood RNAseq analysis showed transient increases in several markers like interferons alpha and gamma after the first dose. First analyses of paired biopsies showed changes in the TME of injected and non-injected lesions. Complete results of cytokine and chemokine analysis in serum and blood RNAseq for the dose escalation cohorts will be presented. Multiplex immunofluorescence and gene expression profiling from paired biopsies from individual patients will be also included.

Conclusions

Intratumoral injection of CV8102 activated several cytokine/chemokine pathways in the peripheral blood and showed immunological changes in the tumor microenvironment of injected and non-injected lesions.

Trial Registration

NCT03291002

References

Ziegler A, Soldner C, Lienenklaus S, Spanier J, Trittel S, Riese P, Kramps T, Weiss S, Heidenreich R, Jasny E, Guzmán CA, Kallen KJ, Fotin-Mleczek M, Kalinke U. A New RNA-Based Adjuvant Enhances Virus-Specific Vaccine Responses by Locally Triggering TLR- and RLH-Dependent Effects. J Immunol 2017;198(4):1595–1605. doi: 10.4049/jimmunol.1601129.

Heidenreich R, Jasny E, Kowalczyk A, Lutz J, Probst J, Baumhof P, Scheel B, Voss S, Kallen KJ, Fotin-Mleczek M. A novel RNA-based adjuvant combines strong immunostimulatory capacities with a favorable safety profile. Int J Cancer 2015 Jul 15;137(2):372–84. doi: 10.1002/ijc.29402.

Ethics Approval

The study was approved by the Central Ethics Committees in Tuebingen, Germany under 785/2016AMG1, in France by the COMITE DE PROTECTION DES PERSONNES SUD-EST I under 2019–49, approval dated 17-May-2019, in Barcelona, Spain by the CEC COMITÉ DE ÉTICA DE INVESTIGACIÓN CLÍNICA CON MEDICAMENTOS del Hospital Universitari Vall d’Hebron, approval date 28-Nov-2019 under the EUdraCT number, in Austria by the Central Ethics Committee in Graz under 31–426 ex 18/19 approved on 19-Sep-2019.

Consent

Written informed consent from the patient was obtained for publication of this abstract and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.

Safety and immunogenicity of an mRNA-lipid nanoparticle vaccine candidate against SARS-CoV-2 : A phase 1 randomized clinical trial

BACKGROUND

We used the RNActive® technology platform (CureVac N.V., Tübingen, Germany) to prepare CVnCoV, a COVID-19 vaccine containing sequence-optimized mRNA coding for a stabilized form of SARS-CoV‑2 spike (S) protein encapsulated in lipid nanoparticles (LNP).

METHODS

This is an interim analysis of a dosage escalation phase 1 study in healthy 18-60-year-old volunteers in Hannover, Munich and Tübingen, Germany, and Ghent, Belgium. After giving 2 intramuscular doses of CVnCoV or placebo 28 days apart we assessed solicited local and systemic adverse events (AE) for 7 days and unsolicited AEs for 28 days after each vaccination. Immunogenicity was measured as enzyme-linked immunosorbent assay (ELISA) IgG antibodies to SARS-CoV‑2 S‑protein and receptor binding domain (RBD), and SARS-CoV‑2 neutralizing titers (MN50).

RESULTS

In 245 volunteers who received 2 CVnCoV vaccinations (2 μg, n = 47, 4 μg, n = 48, 6 μg, n = 46, 8 μg, n = 44, 12 μg, n = 28) or placebo (n = 32) there were no vaccine-related serious AEs. Dosage-dependent increases in frequency and severity of solicited systemic AEs, and to a lesser extent local AEs, were mainly mild or moderate and transient in duration. Dosage-dependent increases in IgG antibodies to S‑protein and RBD and MN50 were evident in all groups 2 weeks after the second dose when 100% (23/23) seroconverted to S‑protein or RBD, and 83% (19/23) seroconverted for MN50 in the 12 μg group. Responses to 12 μg were comparable to those observed in convalescent sera from known COVID-19 patients.

CONCLUSION

In this study 2 CVnCoV doses were safe, with acceptable reactogenicity and 12 μg dosages elicited levels of immune responses that overlapped those observed in convalescent sera.

Abstract 2291: On- and off target toxicity profiling for adoptive cell therapy by mass spectrometry-based immunopeptidome analysis of primary human normal tissues

A major constraint for the broad and safe application of Adoptive Cellular Therapy (ACT) is the limited number of validated tumor targets, especially for solid tumors. For T-cell receptor (TCR)-based approaches, presentation of targeted HLA-peptides on normal tissues can lead to on-target toxicity, such as severe inflammatory colitis reported upon re-directing T cells to an HLA-A*02 restricted carcinoembryonic antigen (CEA) epitope. Independently, off-target cross-reactivity of TCRs occurred in previous ACT trials, e.g. when a MAGEA3-directed TCR cross-recognized an HLA-A*01 restricted epitope from titin expressed on heart, which led to fatal cardiac toxicities. Here we present a novel approach allowing the prediction of severe on- and off-target side effects before entering into clinical trials.

We used a target discovery engine (XPRESIDENT) combining highly sensitive, quantitative mass spectrometry (LC-MS/MS), RNA-Seq-based differential transcriptomics, immunology and bioinformatics to characterize the human immunopeptidome directly on shock frozen primary human tissues. Over the last years we have built an according database for &gt; 600 tumor samples from &gt; 20 different tumor types and, importantly, &gt; 300 samples from &gt; 40 different normal tissue types, resulting in hundreds of thousands of unique HLA-peptide sequences. These data allow conclusions on which HLA peptides are actually presented on primary normal tissues in a quantitative manner, taking into account relative differences between normal tissues and tumors as well as absolute peptide copy numbers per cell. In order to assess the off-target risk for a TCR, we predict all theoretical HLA- and TCR-binding peptides in the proteome, ideally based on the binding motif of the TCR, and specifically search for actual peptide presentation by normal tissues.

When analyzing the above described CEA case, we were able to detect the CEA-derived peptide IMIGVLVGV on HLA-A*02 positive colorectal cancer samples, but importantly also on normal colorectal samples. In the original study describing the titin case tremendous experimental efforts and sophisticated cell culture models were required to retrospectively identify cross-recognition of the peptide on cardiomyocytes as the cause of toxicity. In contrast, with our approach we easily and directly identified the critical peptide ESDPIVAQY as one of the most abundantly presented peptides on an HLA-A*01 positive primary human heart sample. We show that this approach can lead to noteworthy results also for other pre-clinical and clinical stage TCR candidates.

In conclusion our data demonstrate that ultrasensitive LC-MS/MS of primary tissue may represent a fast, straightforward and meaningful complementary method to common in vitro or animal models for the prediction of on- and off-target toxicities in TCR-based immunotherapy approaches.

Citation Format: Oliver Schoor, Jens Fritsche, Sarah Kutscher, Andrea Mahr, Lea Stevermann, Annika Sonntag, Franziska Hoffgaard, Dominik Vahrenhorst, Julia Leibold, Valentina Goldfinger, Leonie Alten, Sebastian Bunk, Dominik Maurer, Steffen Walter, Hans-Georg Rammensee, Harpreet Singh-Jasuja, Toni Weinschenk. On- and off target toxicity profiling for adoptive cell therapy by mass spectrometry-based immunopeptidome analysis of primary human normal tissues. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2291.