Role of spontaneous reporting in investigating the relationship between mRNA COVID-19 vaccines and myocarditis: The French perspective.

AIM OF THE STUDY: Post-mRNA coronavirus diseases 2019 (COVID-19) vaccines myocarditis emerged as a rare adverse effect, particularly in adolescents and young adults, and was labeled as such for both vaccines in the summer of 2021. This study aims to summarize the timeline and process of signal detection, substantiation, and quantification of myocarditis cases related to mRNA vaccines in France. METHODS: The intensive monitoring plan for COVID-19 vaccine safety was based on case-by-case analysis of all cases collected in the French spontaneous reporting database (Base nationale de pharmacovigilance, BNPV). Cases were evaluated by drug safety medical professionals and discussed at a national level for signal detection purposes. Reported cases were compared to the number of vaccine-exposed persons up to September 30th, 2021. Reporting rates (Rr) of myocarditis per 100,000 injections were calculated and stratified according to age, gender, and injection rank of BNT162b2 and mRNA-1273 vaccines. Poisson distribution was used to compute Rrs 95% Confidence Interval (95% CI). RESULTS: The case-by-case analysis detected a possible cluster of myocarditis in April 2021 (5 cases, 4 after the 2nd injection). In June 2021, the signal was substantiated with 12 cases (9 related to BNT162b2, and 3 to mRNA-1273). As of September 2021, almost 73 million BNT162b2 and 10 million mRNA-1273 doses had been injected. The Rr per 100,000 injections was 0.5 (0.5-0.6) for BNT162b2 and 1.1 (95% CI 0.9-1.3) for mRNA-1273. The difference among vaccines was more pronounced after the second injection, particularly in men aged 18-24 years (4.3 [3.4-5.5] for BNT162b2 vs. 13.9 [9.2-20.1] for mRNA-1273) and aged 25-29 years (1.9 [1.2-2.9] vs. 7.0 [3.4-12.9]). CONCLUSION: The study highlighted the role of the spontaneous reporting system in the detection, assessment, and quantification of myocarditis related to m-RNA vaccines. It suggested from September 2021 that mRNA-1273 was reasonably related to a higher risk of myocarditis than BNT162b2 in people under 30, particularly after the second injection.

Curative or pre-emptive adenovirus-specific T cell transfer from matched unrelated or third party haploidentical donors after HSCT, including UCB transplantations: a successful phase I/II multicenter clinical trial.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (HSCT), the most widely used potentially curable cellular immunotherapeutic approach in the treatment of hematological malignancies, is limited by life-threatening complications: graft versus host disease (GVHD) and infections especially viral infections refractory to antiviral drugs. Adoptive transfer of virus-specific T cells is becoming an alternative treatment for infections following HSCT. We report here the results of a phase I/II multicenter study which includes a series of adenovirus-specific T cell (ADV-VST) infusion either from the HSCT donor or from a third party haploidentical donor for patients transplanted with umbilical cord blood (UCB). METHODS: Fourteen patients were eligible and 11 patients received infusions of ADV-VST generated by interferon (IFN)-γ-based immunomagnetic isolation from a leukapheresis from their original donor (42.9%) or a third party haploidentical donor (57.1%). One patient resolved ADV infection before infusion, and ADV-VST could not reach release or infusion criteria for two patients. Two patients received cellular immunotherapy alone without antiviral drugs as a pre-emptive treatment. RESULTS: One patient with adenovirus infection and ten with adenovirus disease were infused with ADV-VST (mean 5.83 ± 8.23 × 103 CD3+IFN-γ+ cells/kg) up to 9 months after transplantation. The 11 patients showed in vivo expansion of specific T cells up to 60 days post-infusion, associated with adenovirus load clearance in ten of the patients (91%). Neither de novo GVHD nor side effects were observed during the first month post-infusion, but GVHD reactivations occurred in three patients, irrespective of the type of leukapheresis donor. For two of these patients, GVHD reactivation was controlled by immunosuppressive treatment. Four patients died during follow-up, one due to refractory ADV disease. CONCLUSIONS: Adoptive transfer of rapidly isolated ADV-VST is an effective therapeutic option for achieving in vivo expansion of specific T cells and clearance of viral load, even as a pre-emptive treatment. Our study highlights that third party haploidentical donors are of great interest for ADV-VST generation in the context of UCB transplantation. (N° Clinical trial.gov: NCT02851576, retrospectively registered).