SARS-CoV-2 vaccines are not associated with hypercoagulability in apparently healthy people.

Background: SARS-CoV-2 adenoviral-vector-DNA vaccines have been linked to the rare but serious thrombotic post-vaccine complication vaccine-induced immune thrombotic thrombocytopenia (VITT). This has raised concerns regarding the possibility of increased thrombotic risk after any SARS-CoV-2 vaccines. Objectives: To investigate whether SARS-CoV-2 vaccines cause coagulation activation leading to a hypercoagulable state. Methods: This observational study included 567 healthcare personnel, 521 were recruited post-vaccination after a first dose of adenoviral vector ChAdOx1-S (Vaxzevria®, AstraZeneca) vaccine, and 46 prospectively before vaccination with an mRNA vaccine, either Spikevax® (Moderna, n=38) or Comirnaty® (Pfizer-BioNTech, n=8). In the mRNA group, samples were acquired before and 1-2 weeks after vaccination. In addition to pre-vaccination samples, 56 unvaccinated blood donors were recruited as controls (total n=102). Thrombin generation, D-dimer and free tissue factor pathway inhibitor (TFPI) were analyzed. Results: No participant experienced thrombosis, VITT or thrombocytopenia (platelet count <100·109/L) one week to one month post-vaccination. There was no increase in thrombin generation, D-dimer or TFPI in the ChAdOx1-S vaccine group compared with controls, or after the mRNA vaccines compared with baseline values. Eleven of 513 vaccinated with ChAdOx1-S (2.1%) had anti-PF4/polyanion antibodies without concomitant increase in thrombin generation. Conclusion: In this study, SARS-CoV-2 vaccines were not associated with thrombosis, thrombocytopenia, increased thrombin generation, D-dimer or TFPI levels compared with baseline or unvaccinated controls. These findings argue against subclinical activation of coagulation post-COVID-19 vaccination.

An observational study to identify the prevalence of thrombocytopenia and anti-PF4/polyanion antibodies in Norwegian health care workers after COVID-19 vaccination.

BACKGROUND: The COVID-19 vaccine from AstraZeneca (AZD1222) is one of several vaccines introduced to provide immunity against SARS-CoV-2. Recently, more than 50 cases have been reported presenting a combination of thrombosis, thrombocytopenia, and remarkably high levels of anti-platelet factor 4 (PF4)/polyanion antibodies post-AZD1222 vaccination. Now linked to the vaccine, the condition is referred to as vaccine-induced immune thrombotic thrombocytopenia. The European Medicines Agency still recommends vaccination with AZD1222, but several European countries have temporally paused and/or restricted its use because of the perceived risk of this severe side effect. Because there is no description of PF4/polyanion antibody testing in the clinical trials, knowledge about the prevalence of such antibodies in a vaccinated cohort is needed. OBJECTIVES: To investigate prevalence of thrombocytopenia and anti-PF4/polyanion antibodies in a population recently vaccinated with AZD1222. PATIENTS/METHODS: Four hundred and ninety-two health care workers recently vaccinated with the first dose of AZD1222 were recruited from two hospitals in Norway. Study individuals were screened for thrombocytopenia and the presence of anti-PF4/polyanion antibodies with a PF4/PVS immunoassay. Side effects after vaccination were registered. RESULTS: The majority of study participants had normal platelet counts and negative immunoassay. Anti-PF4/polyanion antibodies without platelet activating properties were only detected in six individuals (optical density ≥0.4, range 0.58-1.16), all with normal platelet counts. No subjects had severe thrombocytopenia. CONCLUSIONS: We found low prevalence of both thrombocytopenia and antibodies to PF4/polyanion-complexes among Norwegian health care workers after vaccination with AZD1222.

Seventy patients treated for COVID-19 by Østfold Hospital Trust. / 70 pasienter med covid-19 innlagt ved Sykehuset Østfold.

BACKGROUND: There is a need for further data on the COVID-19 situation in Norway. Our aim was to describe the patients admitted to our local hospital with COVID-19 in the spring of 2020. MATERIAL AND METHOD: Data were retrieved retrospectively from our local quality register for COVID-19 and include all patients admitted to Østfold Hospital in the period 10 March 2020-31 May 2020. RESULTS: A total of 70 patients were admitted, of whom 47 (67 %) were men. The mean age was 59 years (range 18-95). The most common comorbid conditions were obesity (n = 22, 31 %), chronic coronary artery disease (n = 21, 30 %) and diabetes (n = 17, 24 %). Thirteen patients (19 %) had no comorbidities. The most common symptoms were cough (n = 56, 80 %), dyspnoea (n = 51, 73 %) and fever (n = 48, 69 %). The most frequent complications were cardiac manifestations (n = 18, 26 %), acute respiratory distress syndrome (n = 14, 20 %) and acute kidney injury (n = 9, 13 %). Four (6 %) patients developed venous thromboembolism. Twenty patients (29 %) became critically ill. Thirteen (19 %) received treatment in the intensive care unit, and seven (10 %) died while in hospital. INTERPRETATION: Most of those admitted were middle-aged men. Many had no comorbidities. The most frequent non-respiratory complications were cardiac manifestations and kidney injury. A large proportion of patients became critically ill secondary to acute respiratory distress syndrome.

Persistent symptoms 1.5-6 months after COVID-19 in non-hospitalised subjects: a population-based cohort study.

This study assessed symptoms and their determinants 1.5-6 months after symptom onset in non-hospitalised subjects with confirmed COVID-19 until 1 June 2020, in a geographically defined area. We invited 938 subjects; 451 (48%) responded. They reported less symptoms after 1.5-6 months than during COVID-19; median (IQR) 0 (0-2) versus 8 (6-11), respectively (p<0.001); 53% of women and 67% of men were symptom free, while 16% reported dyspnoea, 12% loss/disturbance of smell, and 10% loss/disturbance of taste. In multivariable analysis, having persistent symptoms was associated with the number of comorbidities and number of symptoms during the acute COVID-19 phase.