tetano
Editor, Senior Moderator
Res Pract Thromb Haemost
. 2021 Oct 11;5(7):e12600.
doi: 10.1002/rth2.12600. eCollection 2021 Oct.
Prevalence of anti-platelet factor 4/polyanionic antibodies after COVID-19 vaccination with ChAdOx1 nCoV-19 and CoronaVac in Thais
Phichchapha Noikongdee[SUP] 1 [/SUP], Pornnapa Police[SUP] 1 [/SUP], Tichayapa Phojanasenee[SUP] 1 [/SUP], Pichika Chantrathammachart[SUP] 1 [/SUP], Pimjai Niparuck[SUP] 1 [/SUP], Teeraya Puavilai[SUP] 1 [/SUP], Angsana Phuphuakrat[SUP] 1 [/SUP], Pantep Angchaisuksiri[SUP] 1 [/SUP], Kochawan Boonyawat[SUP] 1 [/SUP]
Affiliations
Abstract
Introduction: Vaccine-induced thrombotic thrombocytopenia (VITT) has been reported after vaccination with the adenoviral vector coronavirus disease 2019 (COVID-19) vaccine ChAdOx1 nCoV-19 in European countries. To date, two cases of VITT have been reported in Thais after COVID-19 vaccination. We determined the frequency of anti-platelet factor 4 (PF4)/polyanionic antibodies in the Thai population receiving the COVID-19 vaccines.
Methods: We conducted a cross-sectional study to evaluate the prevalence of anti-PF4/polyanionic antibodies in health care workers who received COVID-19 vaccination with ChAdOx1 nCoV-19 or CoronaVac within 7 to 35 days. A control population who had not been vaccinated was also included. Anti-PF4/polyanionic antibodies were detected using ELISA. Functional assay with platelet aggregation was performed for all positive anti-PF4/polyanionic antibody ELISA tests.
Results: A total of 646 participants were included in the study; 221 received ChAdOx1 nCoV-19, 232 received CoronaVac, and 193 participants were in the control group. The prevalence of anti-PF4 antibodies was 2.3% (95% confidence interval [CI], 0.7-5.2), 1.7% (95% CI, 0.5-4.4) in the ChAdOx1 nCoV-19 and CoronaVac groups, respectively. There was no positive test in the control group. None of the PF4/polyanionic positive sera induced platelet aggregation.
Conclusion: We found a low prevalence of anti-PF4 antibodies in Thais after vaccination with ChAdOx1 nCoV-19 and CoronaVac. None of the antibodies were functional and lacked an association with VITT.
Keywords: COVID‐19 vaccines; Platelet factor 4; Prevalence; Thailand; Vaccines.
. 2021 Oct 11;5(7):e12600.
doi: 10.1002/rth2.12600. eCollection 2021 Oct.
Prevalence of anti-platelet factor 4/polyanionic antibodies after COVID-19 vaccination with ChAdOx1 nCoV-19 and CoronaVac in Thais
Phichchapha Noikongdee[SUP] 1 [/SUP], Pornnapa Police[SUP] 1 [/SUP], Tichayapa Phojanasenee[SUP] 1 [/SUP], Pichika Chantrathammachart[SUP] 1 [/SUP], Pimjai Niparuck[SUP] 1 [/SUP], Teeraya Puavilai[SUP] 1 [/SUP], Angsana Phuphuakrat[SUP] 1 [/SUP], Pantep Angchaisuksiri[SUP] 1 [/SUP], Kochawan Boonyawat[SUP] 1 [/SUP]
Affiliations
- PMID: 34667921
- PMCID: PMC8505225
- DOI: 10.1002/rth2.12600
Abstract
Introduction: Vaccine-induced thrombotic thrombocytopenia (VITT) has been reported after vaccination with the adenoviral vector coronavirus disease 2019 (COVID-19) vaccine ChAdOx1 nCoV-19 in European countries. To date, two cases of VITT have been reported in Thais after COVID-19 vaccination. We determined the frequency of anti-platelet factor 4 (PF4)/polyanionic antibodies in the Thai population receiving the COVID-19 vaccines.
Methods: We conducted a cross-sectional study to evaluate the prevalence of anti-PF4/polyanionic antibodies in health care workers who received COVID-19 vaccination with ChAdOx1 nCoV-19 or CoronaVac within 7 to 35 days. A control population who had not been vaccinated was also included. Anti-PF4/polyanionic antibodies were detected using ELISA. Functional assay with platelet aggregation was performed for all positive anti-PF4/polyanionic antibody ELISA tests.
Results: A total of 646 participants were included in the study; 221 received ChAdOx1 nCoV-19, 232 received CoronaVac, and 193 participants were in the control group. The prevalence of anti-PF4 antibodies was 2.3% (95% confidence interval [CI], 0.7-5.2), 1.7% (95% CI, 0.5-4.4) in the ChAdOx1 nCoV-19 and CoronaVac groups, respectively. There was no positive test in the control group. None of the PF4/polyanionic positive sera induced platelet aggregation.
Conclusion: We found a low prevalence of anti-PF4 antibodies in Thais after vaccination with ChAdOx1 nCoV-19 and CoronaVac. None of the antibodies were functional and lacked an association with VITT.
Keywords: COVID‐19 vaccines; Platelet factor 4; Prevalence; Thailand; Vaccines.