Intracerebral hemorrhage associated with vaccine-induced thrombotic thrombocytopenia following ChAdOx1 nCOVID-19 vaccine in a pregnant woman

Vaccine-induced immune thrombotic thrombocytopenia post COVID-19 booster vaccination in Brazil: a case series

Background

The emergence of new variants of SARS-CoV-2 has led to the administration of different booster vaccines to mitigate COVID-19. Vaccines with adenoviral vectors have been rarely associated with vaccine-induced immune thrombotic thrombocytopenia (VITT).

Objectives

This study aimed to describe 15 cases of VITT after the third and fourth doses of the COVID-19 vaccine in Brazil.

Methods

Cases were reported after all kinds of anti-SARS-CoV-2 booster vaccinations between October 17, 2021, and September 4, 2022.

Results

Of the 26 suspected cases, 15 cases of VITT were analyzed. Of these, 10 were classified as definite VITT, 2 as probable, 1 as possible, and 2 as unlikely. The estimated frequency of definite, probable, or possible VITT was 0.33 cases per million. Cases were assigned to ChAdOx1 (13 cases), Ad26.COV2.S (1 case), and BNT162b2 (1 case). None of the patients received an adenoviral vaccine as a primary vaccination. The average age of participants was 34 years, and symptoms usually appeared 8 days after vaccination. Headache was the most common symptom, and cerebral veins were the most affected thrombotic site. The overall mortality risk was 53%. Anti-platelet factor 4 enzyme-linked immunosorbent assay serology was positive in 11 out of 15 patients (73.3%), negative in 2 (13.3%), and missing in 2 (13.3%).

Conclusion

The study confirms that VITT is linked to the first exposure to adenoviral vector vaccines. Since January 2023, Brazil has recommended preferably COVID-19 messenger RNA vaccines for individuals aged 18 to 39 years. We suggest that, in the current disease scenario, COVID-19 adenovirus vaccines should not be the first choice for individuals aged <50 years who have not received a previous dose of this type of vaccine.

The Real-World Study of Immunogenicity and Safety of the Adjuvant Recombinant Vaccine against Varicella Zoster Virus in Patients with Immune-Mediated Inflammatory Diseases Treated with Janus Kinase Inhibitors

Background. The risk of herpes zoster reactivation is increased in immunocompromised patients, especially in those with immune-mediated inflammatory diseases (IMIDs) on Janus kinase inhibitor (JAKi) treatment. The recombinant subunit herpes zoster vaccine (RZV) is a non-live vaccine, recently approved for this subgroup of patients, which shows high rates of vaccine effectiveness, with few adverse effects reported in clinical trials. Purpose. The aim of this real-world study was to determine the immunogenicity and safety of RZV in IMID patients on JAKi treatment. Methods. The increase in the concentration of anti-gE antibody for varicella zoster virus post-vaccination, compared to the pre-vaccination concentration, was analyzed to test the humoral immune response. Adverse effects after the first and second vaccine doses were registered. Results. In total, 49 patients were analyzed, and a fourfold increase in antibody concentration was achieved in almost 40% of subjects, with only one serious local adverse effect. Discussion. The resulting immunogenicity was lower than that observed in clinical trials, probably due to the presence of immune disease and immunosuppressive treatment, and to the fact that this was a real-world study. No differences in response according to age, previous virus zoster reactivation, or concomitant treatments were found. Conclusions. RZV was well tolerated and reached the immune response objective in 40% of patients. These results reinforce the importance of including RZV vaccination for immunosuppressed patients. Real-world studies regarding vaccine effectiveness are still needed in order to gain a full understanding of the response to RZV in this group of patients.

Proteomic Profile of Procoagulant Extracellular Vesicles Reflects Complement System Activation and Platelet Hyperreactivity of Patients with Severe COVID-19

Background

Extracellular vesicles (EVs) are a valuable source of biomarkers and display the pathophysiological status of various diseases. In COVID-19, EVs have been explored in several studies for their ability to reflect molecular changes caused by SARS-CoV-2. Here we provide insights into the roles of EVs in pathological processes associated with the progression and severity of COVID-19.

Methods

In this study, we used a label-free shotgun proteomic approach to identify and quantify alterations in EV protein abundance in severe COVID-19 patients. We isolated plasma extracellular vesicles from healthy donors and patients with severe COVID-19 by size exclusion chromatography (SEC). Then, flow cytometry was performed to assess the origin of EVs and to investigate the presence of circulating procoagulant EVs in COVID-19 patients. A total protein extraction was performed, and samples were analyzed by nLC-MS/MS in a Q-Exactive HF-X. Finally, computational analysis was applied to signify biological processes related to disease pathogenesis.

Results

We report significant changes in the proteome of EVs from patients with severe COVID-19. Flow cytometry experiments indicated an increase in total circulating EVs and with tissue factor (TF) dependent procoagulant activity. Differentially expressed proteins in the disease groups were associated with complement and coagulation cascades, platelet degranulation, and acute inflammatory response.

Conclusions

The proteomic data reinforce the changes in the proteome of extracellular vesicles from patients infected with SARS-CoV-2 and suggest a role for EVs in severe COVID-19.

Systematic review and meta-analysis of the effectiveness and perinatal outcomes of COVID-19 vaccination in pregnancy

Safety and effectiveness of COVID-19 vaccines during pregnancy is a particular concern affecting vaccination uptake by this vulnerable group. Here we evaluated evidence from 23 studies including 117,552 COVID-19 vaccinated pregnant people, almost exclusively with mRNA vaccines. We show that the effectiveness of mRNA vaccination against RT-PCR confirmed SARS-CoV-2 infection 7 days after second dose was 89·5% (95% CI 69·0-96·4%, 18,828 vaccinated pregnant people, I² = 73·9%). The risk of stillbirth was significantly lower in the vaccinated cohort by 15% (pooled OR 0·85; 95% CI 0·73–0·99, 66,067 vaccinated vs. 424,624 unvaccinated, I² = 93·9%). There was no evidence of a higher risk of adverse outcomes including miscarriage, earlier gestation at birth, placental abruption, pulmonary embolism, postpartum haemorrhage, maternal death, intensive care unit admission, lower birthweight Z-score, or neonatal intensive care unit admission (p > 0.05 for all). COVID-19 mRNA vaccination in pregnancy appears to be safe and is associated with a reduction in stillbirth.

Pregnant women have been disproportionately under-vaccinated against COVID-19, partly because they were excluded from initial trials. This systematic review and meta-analysis supports efficacy of vaccination in pregnancy, and finds no evidence of adverse maternal or perinatal outcomes.

Cardiovascular Complications of COVID-19 Vaccines

Coronavirus disease 2019 (COVID-19) has become a global public health catastrophe. Vaccination against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is proven to be the most effective measure to suppress the pandemic. With the widespread application of the four vaccines, namely, ChAdOx1, Ad26.COV2.S, BNT162b2, and mRNA-1273.2, several adverse effects have been reported. The most serious type of complication is cardiovascularly related, including myocarditis, immune thrombocytopenia (ITP), cerebral sinus venous thrombosis, among others. All these adverse events undermine the health of the vaccinees and affect the administration of the vaccines. As the distribution of COVID-19 vaccines is surrounded by suspicion and rumors, it is essential to provide the public with accurate reports from trusted experts and journals. Monitoring the safety of COVID-19 vaccines is an important and ongoing process that is also urgent. Thus, we summarized the cardiovascular complications of the major types of COVID-19 vaccines, including mRNA vaccines, which are now generally considered to be innovative vaccines, and the future for vaccination against COVID-19, in addition to the underlying pathogenesis and potential therapeutics.

Thrombosis with Thrombocytopenia Syndrome After Administration of AZD1222 or Ad26.COV2.S Vaccine for COVID-19: A Systematic Review

BACKGROUND

Cases of thrombosis with thrombocytopenia syndrome (TTS) have been reported following vaccination with AZD1222 or Ad26.COV2.S. This review aimed to explore the pathophysiology, epidemiology, diagnosis, management, and prognosis of TTS.

METHODS

A systematic review was conducted to identify evidence on TTS till 4th September 2021. Case reports and series reporting patient-level data were included. Descriptive statistics were reported and compared across patients with different sexes, age groups, vaccines, types of thrombosis, and outcomes.

FINDINGS

Sixty-two studies reporting 160 cases were included from 16 countries. Patients were predominantly females with a median age of 42.50 (22) years. AZD1222 was administered to 140 patients (87·5%). TTS onset occurred in a median of 9 (4) days after vaccination. Venous thrombosis was most common (61.0%). Most patients developed cerebral venous sinus thrombosis (CVST; 66.3%). CVST was significantly more common in female vs male patients (p = 0·001) and in patients aged <45 years vs ≥45 years (p = 0·004). The mortality rate was 36.2%, and patients with suspected TTS, venous thrombosis, CVST, pulmonary embolism, or intraneural complications, patients not managed with non-heparin anticoagulants or IVIG, patients receiving platelet transfusions, and patients requiring intensive care unit admission, mechanical ventilation, or inpatient neurosurgery were more likely to expire than recover.

INTERPRETATION

These findings help to understand the pathophysiology of TTS while also recommending diagnostic and management approaches to improve prognosis in patients.

FUNDING

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.