Session Information
Session Type: Poster Session B
Session Time: 9:00AM-10:30AM
Background/Purpose: Patients under immunosuppressive therapy have a high risk for severe COVID-19 disease courses. However, efficacy of vaccination and therefore the right vaccination strategy remains unclear particularly in these individuals at risk.
The aim of the study was to investigate the efficacy of safety of a COVID-19 booster vaccination comparing homologous versus heterologous vaccination strategies in patients who did not seroconvert upon primary vaccination with an mRNA-based vaccine.
Methods: 75 patients under immunosuppressive treatment who received two doses of an mRNA vaccine with either BNT162b2 (Pfizer–BioNTech) or mRNA-1273 (Moderna) were screened. 51 patients without humoral immune response were randomized and of those 46 received a third dose of either the same mRNA or the vector vaccine ChAdOx1 nCoV-19 (Oxford-AstraZeneca). In this blinded clinical trial, the primary endpoint was defined as the difference in the SARS-CoV-2 antibody seroconversion rate four weeks after an additional booster vaccination with a heterologous (vector) versus homologous (mRNA) vaccine. Further endpoints included the overall seroconversion rate and cellular immune response; safety was evaluated until week four. SARS-CoV-2-specific T-cell responses were determined by ELISpot assay in patients and healthy controls. A paper-based patient diary was used to evaluate adverse events within the first week after vaccination.
Results: Seroconversion rates at week four were higher in the mRNA (15/24 patients, 63%) as compared to the vector vaccine groups (4/22 patients, 18%; p=0.006). Overall, 41% of patients seroconverted after an additional booster vaccination. SARS-CoV-2-specific T-cell responses were similarly increased after a third dose of either vector or mRNA vaccine. In a multivariable logistic regression analysis, patient age and vaccine type were associated with seroconversion. No serious adverse event was attributed to COVID-19 booster vaccination.
Conclusion: Homologous SARS-CoV-2 vaccination was found to be superior to a heterologous vaccination regimen and should be applied in non-seroconverted patients under immunosuppression.
To cite this abstract in AMA style:
Sieghart D, Mrak D, Simader E, Tobudic S, Radner H, Mandl P, Göschl L, Koblischke M, Hommer N, Hartl L, Hofer P, Kartnig F, Hummel T, Kerschbaumer A, Deimel T, Puchner A, Thalhammer R, Zuckermann A, Stiasny K, Perkmann T, Haslacher H, Zeitlinger M, Wiedermann U, Aberle J, Aletaha D, Heinz L, Bonelli M. Heterologous Vector versus Homologous mRNA COVID-19 Booster Vaccination in Non-seroconverted Immunosuppressed Patients: A Randomized Controlled Trial [abstract]. Arthritis Rheumatol. 2022; 74 (suppl 9). https://acrabstracts.org/abstract/heterologous-vector-versus-homologous-mrna-covid-19-booster-vaccination-in-non-seroconverted-immunosuppressed-patients-a-randomized-controlled-trial/. Accessed .« Back to ACR Convergence 2022
ACR Meeting Abstracts - https://acrabstracts.org/abstract/heterologous-vector-versus-homologous-mrna-covid-19-booster-vaccination-in-non-seroconverted-immunosuppressed-patients-a-randomized-controlled-trial/