RT Journal Article
SR Electronic
T1 Vascular thrombosis after single dose Ad26.COV2.S vaccine in healthcare workers in South Africa: open label, single arm, phase 3B study (Sisonke study)
JF BMJ Medicine
JO bmjmed
FD BMJ Publishing Group Ltd
SP e000302
DO 10.1136/bmjmed-2022-000302
VO 2
IS 1
A1 Jacobson, Barry Frank
A1 Schapkaitz, Elise
A1 Takalani, Azwi
A1 Rowji, Pradeep
A1 Louw, Vernon Johan
A1 Opie, Jessica
A1 Bekker, Linda-Gail
A1 Garrett, Nigel
A1 Goga, Ameena
A1 Reddy, Tarylee
A1 Yende-Zuma, Nonhlanhla
A1 Sanne, Ian
A1 Seocharan, Ishen
A1 Peter, Jonny
A1 Robinson, Michelle
A1 Collie, Shirley
A1 Khan, Amber
A1 Takuva, Simbarashe
A1 Gray, Glenda
YR 2023
UL http://bmjmedicine.bmj.com/content/2/1/e000302.abstract
AB Objective To assess the rates of vascular thrombotic adverse events in the first 35 days after one dose of the Ad26.COV2.S vaccine (Janssen/Johnson & Johnson) in healthcare workers in South Africa and to compare these rates with those observed in the general population.Design Open label, single arm, phase 3B study.Setting Sisonke study, South Africa, 17 February to 15 June 2021.Participants The Sisonke cohort of 477 234 healthcare workers, aged ≥18 years, who received one dose of the Ad26.COV2.S vaccine.Main outcome measures Observed rates of venous arterial thromboembolism and vaccine induced immune thrombocytopenia and thrombosis in individuals who were vaccinated, compared with expected rates, based on age and sex specific background rates from the Clinical Practice Research Datalink GOLD database (database of longitudinal routinely collected electronic health records from UK primary care practices using Vision general practice patient management software).Results Most of the study participants were women (74.9%) and median age was 42 years (interquartile range 33-51). Twenty nine (30.6 per 100 000 person years, 95% confidence interval 20.5 to 44.0) vascular thrombotic events occurred at a median of 14 days (7-29) after vaccination. Of these 29 participants, 93.1% were women, median age 46 (37-55) years, and 51.7% had comorbidities. The observed to expected ratios for cerebral venous sinus thrombosis with thrombocytopenia and pulmonary embolism with thrombocytopenia were 10.6 (95% confidence interval 0.3 to 58.8) and 1.2 (0.1 to 6.5), respectively. Because of the small number of adverse events and wide confidence intervals, no conclusions were drawn between these estimates and the expected incidence rates in the population.Conclusions Vaccine induced immune thrombocytopenia and thrombosis after one dose of the Ad26.COV2.S vaccine was found in only a few patients in this South African population of healthcare workers. These findings are reassuring if considered in terms of the beneficial effects of vaccination against covid-19 disease. These data support the continued use of this vaccine, but surveillance is recommended to identify other incidences of venous and arterial thromboembolism and to improve confidence in the data estimates.Trial registration ClinicalTrials.gov NCT04838795.All data relevant to the study are included in the article or uploaded as supplementary information.