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Res Pract Thromb Haemost
. 2023 Jan 14;100049.
doi: 10.1016/j.rpth.2023.100049. Online ahead of print.
No changes in haemostasis after COVID-19-heterologous vaccination schedule: a sub analysis of the phase 2 CombiVacS study
Nora V Butta 1 , Elena G Arias-Salgado 1 , Elena Monzón Manzano 1 , Paula Acuña 1 , María Teresa Álvarez Román 2 , Antonio Buño-Soto 3 , Juan Carlos Ramos Ramos 4 , Cristóbal Belda-Iniesta 5 , Jesús Frías 6 7 8 9 10 , Antonio J Carcas 6 7 8 9 10 , Lucía Martínez de Soto 6 8 , Rosa de Miguel Buckley 4 , David Lora 8 11 , María Teresa García-Morales 8 11 , Alberto M Borobia 6 7 8 9 10 , José Ramón Arribas 10 12 , Víctor Jiménez Yuste 2 ; CombiVacS study Group
Affiliations
- PMID: 36685004
- PMCID: PMC9840220
- DOI: 10.1016/j.rpth.2023.100049
Abstract
Background: Several cases of unusual thrombotic events and thrombocytopenia were described after vaccination with recombinant adenoviral vectors encoding the spike protein antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Objectives: To elucidate the impact of a COVID-19 heterologous vaccination schedule, including priming with an adenovirus vaccine, on haemostasis profile.
Methods: The present study is a subanalysis of the CombiVacS clinical trial initiated in April 2021, that included adult participants previously vaccinated with a single dose of ChAdOx1-S. Between 8-12 weeks after vaccination they were randomly assigned (2:1) to receive either BNT162b2 vaccine (intervention group, n=99) or continue observation (control group, n=50). Samples drawn before and 28 days after a vaccination with BNT162b2 were analysed for platelet count and markers of haemostasis (D-dimer, anti-PF4 antibodies, cfDNA, PAI-1, thrombin generation, and serum capacity to activate platelets).
Results: Platelet count from all participants after receiving BNT162b2 was within normal range. Anti-PF4 antibodies were present in 26% and 18% of subjects from the control and intervention group, respectively, at day 28. In most cases levels of anti-PF4antibodies were high before receiving BNT162b2. Serum from these participants did not activate platelets from healthy controls. There were no differences between groups in PAI-1 and cfDNA plasma levels. According to D-dimer plasma concentration, thrombin generation test showed that none of the participants had a procoagulant profile.
Conclusions: Our data suggest the heterologous vaccination against COVID-19 infection with ChAdOx1-S and a second dose with BNT162b2 might be safety in terms of haemostasis.
Keywords: COVID-19 vaccine; CombiVacS study; anti-PF4-antibodies; coagulation; haemostasis; heterologous vaccination; thrombocytopenia.