Acceptance and Effectiveness of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) Vaccination in Systemic Sclerosis Patients Treated by Autologous Hematopoietic Stem Cell Transplantation

On December 27th 2020, the implementation of SARS-CoV-2 vaccination in France first became available amongst all immunosuppressed patients at very high risk of severe Coronavirus Disease (COVID-19) infection, specifically for Hematopoietic Stem Cell Transplant recipients or other fragile immunosuppressed patients.

Systemic sclerosis (SSc) is an autoimmune disease characterized by dysregulation of the immune system, vascular damage and progressive fibrosis of the skin and internal organs (heart, lung and kidney) which may lead to severe comorbidities and SSc-related mortality. In severe rapidly progressive SSc, we and others demonstrated that autologous hematopoietic stem cell transplantation (AHSCT) is the only treatment so far allowing improvement in overall and event free survival up to 7 years after AHSCT.

As soon as vaccines were available on January 1st, 2021 and following the French Haute Autorité de Santé (HAS) and Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC) good clinical practices (GCP) guidelines, the ad hoc COVID19 vaccinations were proposed to all SSc patients in France, including those previously treated by AHSCT and followed at Maladies Auto Immunes et Thérapie Cellulaire (MATHEC) Center of Reference for stem cell therapy at St-Louis hospital. In July 2021, the Autoimmune Diseases Working Party (ADWP) and the European society for Blood and Marrow Transplantation (EBMT) guidelines recommended vaccination against SARS-CoV2 as early as 3 months after HSCT for autoimmune diseases.

Only one Israeli study so far has analyzed the efficacy of SARS-CoV-2 vaccination after autologous HSCT (AHSCT) in SSc patients..

We therefore designed the present case control study retrospective study to assess the acceptance and effectiveness of this vaccination program in SSc patients treated by AHSCT as compared to other fragile SSc individuals.

The Primary objective is to evaluate the effectiveness of implementing the anti-SARS-CoV2 vaccination program according to the French GCP for COVID-19 prophylaxis in SSc fragile patients, in terms of risk of asymptomatic or symptomatic COVID-19 infection, among SSc patients treated by AHSCT compared to 1:1 matched non transplant SSc controls.


Eligibility Criteria:
Inclusion Criteria:

1. Adults SSc patients fulfilling criteria from the American College of Rheumatology- European League Against Rheumatism for systemic sclerosis, the 1980 criteria from the American College of Rheumatology for systemic sclerosis
2. SSc patients who were offered SARS-CoV-2 vaccination program according to French GCP (with at least either a two-dose mRNA vaccine or single-dose adenoviral vector) between Jan 1st 2021 to June 30th 2022
3. a) Cases: SSc patients, actively followed on Jan 1st 2021 and who underwent treatment by AHSCT therapy from 1998 up to December 31st 2020 b) Controls (non AHSCT): SSc patients, actively followed on Jan 1st 2021 and who had not undergone treatment by AHSCT at that time nor up to June 30th 2022
4. Informed patients followed at Filière des maladies Auto-immunes et Auto Inflammatoires Rares (FAI2R) systemic sclerosis centers: either Centre de Référence des Maladies Rares (CRMR) MATHEC, Maladies Auto-immunes et Thérapie Cellulaire" at Saint-Louis hospital (Paris) or from "Service de Médecine Interne et Immunologie Clinique" at Rangueil hospital (Toulouse).

Exclusion Criteria:

1. SSc patient who were opposed to their data analysis after information about the study