tetano
Editor, Senior Moderator
Res Pract Thromb Haemost
. 2022 Apr 20;6(3):e12698.
doi: 10.1002/rth2.12698. eCollection 2022 Mar.
Risk of thrombosis with thrombocytopenia syndrome after COVID-19 vaccination prior to the recognition of vaccine-induced thrombocytopenia and thrombosis: A self-controlled case series study in England
Hannah Higgins[SUP] 1 [/SUP], Nick Andrews[SUP] 2 [/SUP], Julia Stowe[SUP] 2 [/SUP], Gayatri Amirthalingam[SUP] 2 [/SUP], Mary Ramsay[SUP] 2 [/SUP], Gurpreet Bahra[SUP] 3 [/SUP], Anthony Hackett[SUP] 3 [/SUP], Karen A Breen[SUP] 3 [/SUP], Michael Desborough[SUP] 4 5 [/SUP], Dalia Khan[SUP] 4 5 [/SUP], Heather Leary[SUP] 4 5 [/SUP], Connor Sweeney[SUP] 4 5 [/SUP], Elizabeth Hutchinson[SUP] 4 5 [/SUP], Susan E Shapiro[SUP] 4 5 [/SUP], Charlotte Lees[SUP] 4 5 [/SUP], Jay Dhanapal[SUP] 4 [/SUP], Peter K MacCallum[SUP] 6 7 [/SUP], Shoshana Burke[SUP] 7 [/SUP], Vickie McDonald[SUP] 7 [/SUP], Ngai Mun Aiman Entwistle[SUP] 7 [/SUP], Stephen Booth[SUP] 8 [/SUP], Christina J Atchison[SUP] 9 [/SUP], Beverley J Hunt[SUP] 3 [/SUP]
Affiliations
Abstract
Background: Several studies have found increased risks of thrombosis with thrombocytopenia syndrome (TTS) following the ChAdOx1 vaccination. However, case ascertainment is often incomplete in large electronic health record (EHR)-based studies.
Objectives: To assess for an association between clinically validated TTS and COVID-19 vaccination.
Methods: We used the self-controlled case series method to assess the risks of clinically validated acute TTS after a first COVID-19 vaccine dose (BNT162b2 or ChAdOx1) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Case ascertainment was performed uninformed of vaccination status via a retrospective clinical review of hospital EHR systems, including active ascertainment of thrombocytopenia.
Results: One hundred seventy individuals were admitted to the hospital for a TTS event at the study sites between January 1 and March 31, 2021. A significant increased risk (relative incidence [RI], 5.67; 95% confidence interval [CI], 1.02-31.38) of TTS 4 to 27 days after ChAdOx1 was observed in the youngest age group (18- to 39-year-olds). No other period had a significant increase, although for ChAdOx1 for all ages combined the RI was >1 in the 4- to 27- and 28- to 41-day periods (RI, 1.52; 95% CI, 0.88-2.63; and (RI, 1.70; 95% CI, 0.73-3.8, respectively). There was no significant increased risk of TTS after BNT162b2 in any period. Increased risks of TTS following a positive SARS-CoV-2 test occurred across all age groups and exposure periods.
Conclusions: We demonstrate an increased risk of TTS in the 4 to 27 days following COVID-19 vaccination, particularly for ChAdOx1. These risks were lower than following SARS-CoV-2 infection. An alternative vaccine may be preferable in younger age groups in whom the risk of postvaccine TTS is greatest.
Keywords: COVID‐19; COVID‐19 vaccines; SARS‐CoV‐2; thrombocytopenia; thrombosis.
. 2022 Apr 20;6(3):e12698.
doi: 10.1002/rth2.12698. eCollection 2022 Mar.
Risk of thrombosis with thrombocytopenia syndrome after COVID-19 vaccination prior to the recognition of vaccine-induced thrombocytopenia and thrombosis: A self-controlled case series study in England
Hannah Higgins[SUP] 1 [/SUP], Nick Andrews[SUP] 2 [/SUP], Julia Stowe[SUP] 2 [/SUP], Gayatri Amirthalingam[SUP] 2 [/SUP], Mary Ramsay[SUP] 2 [/SUP], Gurpreet Bahra[SUP] 3 [/SUP], Anthony Hackett[SUP] 3 [/SUP], Karen A Breen[SUP] 3 [/SUP], Michael Desborough[SUP] 4 5 [/SUP], Dalia Khan[SUP] 4 5 [/SUP], Heather Leary[SUP] 4 5 [/SUP], Connor Sweeney[SUP] 4 5 [/SUP], Elizabeth Hutchinson[SUP] 4 5 [/SUP], Susan E Shapiro[SUP] 4 5 [/SUP], Charlotte Lees[SUP] 4 5 [/SUP], Jay Dhanapal[SUP] 4 [/SUP], Peter K MacCallum[SUP] 6 7 [/SUP], Shoshana Burke[SUP] 7 [/SUP], Vickie McDonald[SUP] 7 [/SUP], Ngai Mun Aiman Entwistle[SUP] 7 [/SUP], Stephen Booth[SUP] 8 [/SUP], Christina J Atchison[SUP] 9 [/SUP], Beverley J Hunt[SUP] 3 [/SUP]
Affiliations
- PMID: 35475292
- PMCID: PMC9020167
- DOI: 10.1002/rth2.12698
Abstract
Background: Several studies have found increased risks of thrombosis with thrombocytopenia syndrome (TTS) following the ChAdOx1 vaccination. However, case ascertainment is often incomplete in large electronic health record (EHR)-based studies.
Objectives: To assess for an association between clinically validated TTS and COVID-19 vaccination.
Methods: We used the self-controlled case series method to assess the risks of clinically validated acute TTS after a first COVID-19 vaccine dose (BNT162b2 or ChAdOx1) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Case ascertainment was performed uninformed of vaccination status via a retrospective clinical review of hospital EHR systems, including active ascertainment of thrombocytopenia.
Results: One hundred seventy individuals were admitted to the hospital for a TTS event at the study sites between January 1 and March 31, 2021. A significant increased risk (relative incidence [RI], 5.67; 95% confidence interval [CI], 1.02-31.38) of TTS 4 to 27 days after ChAdOx1 was observed in the youngest age group (18- to 39-year-olds). No other period had a significant increase, although for ChAdOx1 for all ages combined the RI was >1 in the 4- to 27- and 28- to 41-day periods (RI, 1.52; 95% CI, 0.88-2.63; and (RI, 1.70; 95% CI, 0.73-3.8, respectively). There was no significant increased risk of TTS after BNT162b2 in any period. Increased risks of TTS following a positive SARS-CoV-2 test occurred across all age groups and exposure periods.
Conclusions: We demonstrate an increased risk of TTS in the 4 to 27 days following COVID-19 vaccination, particularly for ChAdOx1. These risks were lower than following SARS-CoV-2 infection. An alternative vaccine may be preferable in younger age groups in whom the risk of postvaccine TTS is greatest.
Keywords: COVID‐19; COVID‐19 vaccines; SARS‐CoV‐2; thrombocytopenia; thrombosis.