Thrombotic events and COVID-19 vaccines

Updated Considerations for the Immunopharmacological Aspects of the "Talented mRNA Vaccines"

Messenger RNA (mRNA) vaccines belong to a new class of medications, RNA therapeutics, including both coding and non-coding RNAs. The use of mRNA as a therapy is based on the biological role of mRNA itself, namely its translation into a functional protein. The goal of mRNA vaccines is to produce a specific antigen in cells to elicit an immune response that might be prophylactic or therapeutic. The potential of mRNA as vaccine has been envisaged for years but its efficacy has been clearly demonstrated with the approval of COVID-19 vaccines in 2021. Since then, mRNA vaccines have been in the pipeline for diseases that are still untreatable. There are many advantages of mRNA vaccines over traditional vaccines, including easy and cost-effective production, high safety, and high-level antigen expression. However, the nature of mRNA itself and some technical issues pose challenges associated with the vaccines' development and use. Here we review the immunological and pharmacological features of mRNA vaccines by discussing their pharmacokinetics, mechanisms of action, and safety, with a particular attention on the advantages and challenges related to their administration. Furthermore, we present an overview of the areas of application and the clinical trials that utilize a mRNA vaccine as a treatment.

Effects of Sinovac-Coronavac and Pfizer-BioNTech mRNA vaccines on choroidal and retinal vascular system

PURPOSE

To evaluate the effects of Sinovac-Coronavac and Pfizer-BioNTech mRNA vaccines on choroidal and retinal vascular system using enhanced depth imaging optical coherence tomography (EDI-OCT) and optical coherence tomography angiography (OCTA).

METHODS

In this prospective cross-sectional study, 63 healthy participants (29 with Pfizer-BioNTech, 34 with Sinovac-CoronaVac) were evaluated after the first dose of vaccination. Vessel density (VD) of the superficial (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) were measured with OCTA. Choroidal thickness (CT) were measured with EDI-OCT. Measurements were performed at the 2nd week and the 4th week after vaccinations and compared to pre-vaccination values.

RESULTS

Regarding Pfizer-BioNTech vaccination, CT in the subfoveal and nasal region significantly increased between the pre-vaccination and post-vaccination 2nd week and then significantly decreased to pre-vaccine values at 4th week. The SCP-VD (whole image, fovea, parafovea, perifovea temporal) variables showed a significant decrease at 2nd week. The DCP-VD inferior hemi, parafovea inferior hemi, parafovea inferior variables demonstrated a significant decrease at 2nd week. The perifovea DCP-VD variables also showed a significant decrease at 2nd week, and these variables returned to pre-vaccination values after 4 weeks. The CC-VD variables showed a significant decrease between pre-vaccine and 2nd week post-vaccination. Regarding the Sinovac-CoronaVac vaccination, there was no statistically significant difference in CT and VD values before and after vaccination (p> 0.05).

CONCLUSION

Our study showed significant alterations in retinal vascular density and CT for the Pfizer-BioNTech vaccine at the 2nd week, and these parameters became compatible with pre-vaccination values at the 4th week. In contrast, no differences were observed after the Sinovac-Coronovac vaccination.

Pulmonary Embolism after Vaccination with the COVID-19 Vaccine (Pfizer, BNT162b2): A Case Report

Pulmonary embolism causes pulmonary vascular obstruction and damages circulation, leading to death in serious cases. Various cases of thrombosis have been reported as adverse reactions after vaccination with COVID-19 vaccines, and reliable studies on thrombosis with thrombocytopenia syndrome (TTS) have been confirmed, especially for viral vector vaccines. However, the association with mRNA vaccines has not been proven. We report a case of pulmonary embolism and deep vein thrombosis that occurred after using mRNA COVID-19 vaccines (BNT162b2).

COVID-19, post-acute COVID-19 syndrome (PACS, "long COVID") and post-COVID-19 vaccination syndrome (PCVS, "post-COVIDvac-syndrome"): Similarities and differences

Worldwide there have been over 760 million confirmed coronavirus disease 2019 (COVID-19) cases, and over 13 billion COVID-19 vaccine doses have been administered as of April 2023, according to the World Health Organization. An infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to an acute disease, i.e. COVID-19, but also to a post-acute COVID-19 syndrome (PACS, "long COVID"). Currently, the side effects of COVID-19 vaccines are increasingly being noted and studied. Here, we summarise the currently available indications and discuss our conclusions that (i) these side effects have specific similarities and differences to acute COVID-19 and PACS, that (ii) a new term should be used to refer to these side effects (post-COVID-19 vaccination syndrome, PCVS, colloquially "post-COVIDvac-syndrome"), and that (iii) there is a need to distinguish between acute COVID-19 vaccination syndrome (ACVS) and post-acute COVID-19 vaccination syndrome (PACVS) - in analogy to acute COVID-19 and PACS ("long COVID"). Moreover, we address mixed forms of disease caused by natural SARS-CoV-2 infection and COVID-19 vaccination. We explain why it is important for medical diagnosis, care and research to use the new terms (PCVS, ACVS and PACVS) in order to avoid confusion and misinterpretation of the underlying causes of disease and to enable optimal medical therapy. We do not recommend to use the term "Post-Vac-Syndrome" as it is imprecise. The article also serves to address the current problem of "medical gaslighting" in relation to PACS and PCVS by raising awareness among the medical professionals and supplying appropriate terminology for disease.

Serious adverse event following immunization and thromboembolic events associated with COVID19 vaccination: An analysis of nationwide causality assessment from India

BACKGROUND

Vaccines against the COVID-19 pandemic were introduced in late 2020. The present study has been conducted to study the serious Adverse Events Following Immunization (AEFIs) reported for COVID-19 vaccines from India.

METHODS

Secondary data analysis of the causality assessment reports for the 1112 serious AEFIs published by the Ministry of Health & Family Welfare, Government of India, was conducted. For the current analysis, all the reports published till 29.03.2022 were included. The primary outcome variables analyzed were the consistent causal association and the thromboembolic events.

RESULTS

The majority of the serious AEFIs assessed were either coincidental (578, 52%) or vaccine product related (218, 19.6%). All the serious AEFIs were reported among the Covishield (992, 89.2%) and COVAXIN (120, 10.8%) vaccines. Among these, 401 (36.1%) were deaths, and 711 (63.9%) were hospitalized and recovered. On adjusted analysis, females, the younger age group and non-fatal AEFIs showed a statistically significant consistent causal association with COVID-19 vaccination. Thromboembolic events were reported among 209 (18.8%) of the analyzed participants, with a significant association with higher age and case fatality rate.

CONCLUSION

Deaths reported under serious AEFIs were found to have a relatively lower consistent causal relationship with the COVID-19 vaccines than the recovered hospitalizations in India. No consistent causal association was found between the thromboembolic events and the type of COVID-19 vaccine administered in India.

Personalized predictions of adverse side effects of the COVID-19 vaccines

Background

Misconceptions about adverse side effects are thought to influence public acceptance of the Coronavirus disease 2019 (COVID-19) vaccines negatively. To address such perceived disadvantages of vaccines, a novel machine learning (ML) approach was designed to generate personalized predictions of the most common adverse side effects following injection of six different COVID-19 vaccines based on personal and health-related characteristics.

Methods

Prospective data of adverse side effects following COVID-19 vaccination in 19943 participants from Iran and Switzerland was utilized. Six vaccines were studied: The AZD1222, Sputnik V, BBIBP-CorV, COVAXIN, BNT162b2, and the mRNA-1273 vaccine. The eight side effects were considered as the model output: fever, fatigue, headache, nausea, chills, joint pain, muscle pain, and injection site reactions. The total input parameters for the first and second dose predictions were 46 and 54 features, respectively, including age, gender, lifestyle variables, and medical history. The performances of multiple ML models were compared using Area Under the Receiver Operating Characteristic Curve (ROC-AUC).

Results

The total number of people receiving the first dose of the AZD1222, Sputnik V, BBIBP-CorV, COVAXIN, BNT162b2, and mRNA-1273 were 6022, 7290, 5279, 802, 277, and 273, respectively. For the second dose, the numbers were 2851, 5587, 3841, 599, 242 and 228. The Logistic Regression model for predicting different side effects of the first dose achieved ROC-AUCs of 0.620-0.686, 0.685-0.716, 0.632-0.727, 0.527-0.598, 0.548-0.655, 0.545-0.712 for the AZD1222, Sputnik V, BBIBP-CorV, COVAXIN, BNT162b2 and mRNA-1273 vaccines, respectively. The second dose models yielded ROC-AUCs of 0.777-0.867, 0.795-0.848, 0.857-0.906, 0.788-0.875, 0.683-0.850, and 0.486-0.680, respectively.

Conclusions

Using a large cohort of recipients vaccinated with COVID-19 vaccines, a novel and personalized strategy was established to predict the occurrence of the most common adverse side effects with high accuracy. This technique can serve as a tool to inform COVID-19 vaccine selection and generate personalized factsheets to curb concerns about adverse side effects.

Stimulated Reporting of Adverse Events Following Immunization with COVID-19 Vaccines

In India, up until December 2021, Covishield and Covaxin vaccines against COVID-19 were being used for mass vaccination programs. In view of the urgency of fighting the ongoing pandemic, many vaccines have been granted emergency use approval while phase 2/3 clinical trials were still underway. Even for vaccines that have completed phase 3 trials, safety data may not be comprehensive. This retrospective observational study was conducted at a designated Regional Training Centre for Pharmacovigilance cum Adverse Drug Reaction Monitoring Centre (AMC) under the Pharmacovigilance Programme of India. The data sources were stimulated spontaneous reports of Adverse Events Following Immunization (AEFI) due to the COVID-19 vaccines from 10 January to 31 December 2021. A total of 51,010 COVID vaccine doses were administered during the study period. There were 330 AEFI reported (AEFI rate: 0.65%). Six AEFI were serious events among which three were Adverse Events of Special Interest. The majority of the AEFI were systemic, reported after the first dose, and with an onset between 1 and 24 h after vaccination. On comparing Covishield and Covaxin, there were no statistically significant differences in the AEFI reported with either vaccine in terms of gender, seriousness, lag period, duration, recovery, causality, treatment received for AEFI, presence of co-morbidity, or history of COVID-19 infection. Overall, the rates of AEFI was uncommon, and serious AEFI were rare with both Covishield and Covaxin, with a higher rate after the first dose. Whether immunological tolerance or allayed anxiety was responsible for the lower AEFI risk with the second dose remains to be investigated.

Trial by media: evaluating the role of mainstream media and fact-checking agencies during the COVID-19 pandemic

Purpose

The purpose of this paper is to critically assess the function of the media during the COVID-19 pandemic. It tries to understand how media corporations selectively polish a certain narrative against the other. It will also take into consideration the role of fact-checking agencies and its reliability in determining what is right and wrong.

Design/methodology/approach

This study uses qualitative methods and relies on secondary data available in academic domains. In this paper, a specific case related with the COVID-19 pandemic is taken up. Conflicting accounts of health professionals both in academic and industry are compared and analysed. Professional integrity of fact-checking agencies as well goes through scrutiny.

Findings

After conducting a critical analysis, it is observed that media houses have violated certain ethics while presenting news and opinions during the COVID-19 pandemic. Without any consideration of fair presentation, the mainstream media resorted to presenting vaccine hesitancy as conspiracy and deplatformed such voice from the media. This violates one’s freedom to free speech and expression.

Research limitations/implications

It is a viewpoint from the side of a free speech abolitionist.

Practical implications

Press will realize that it failed in a number of occasions to uphold and protect its ethical values.

Originality/value

A study questioning the role of media during the COVID-9 pandemic is rare. In this regard, adequate literature is always a difficulty considering the amount of censorship imposed by health agencies, academic institutions and the media. This particular study is built of limited yet reliable information made available by academicians and independent health professionals. As such, the value of work which focuses on the alternative perspectives is believed to add value to health professionals, policymakers, media professionals and the general population.

SARS-CoV-2-The Role of Natural Immunity: A Narrative Review

BACKGROUND

Both natural immunity and vaccine-induced immunity to COVID-19 may be useful to reduce the mortality/morbidity of this disease, but still a lot of controversy exists.

AIMS

This narrative review analyzes the literature regarding these two immunitary processes and more specifically: (a) the duration of natural immunity; (b) cellular immunity; (c) cross-reactivity; (d) the duration of post-vaccination immune protection; (e) the probability of reinfection and its clinical manifestations in the recovered patients; (f) the comparisons between vaccinated and unvaccinated as to the possible reinfections; (g) the role of hybrid immunity; (h) the effectiveness of natural and vaccine-induced immunity against Omicron variant; (i) the comparative incidence of adverse effects after vaccination in recovered individuals vs. COVID-19-naïve subjects.

MATERIAL AND METHODS

through multiple search engines we investigated COVID-19 literature related to the aims of the review, published since April 2020 through July 2022, including also the previous articles pertinent to the investigated topics.

RESULTS

nearly 900 studies were collected, and 246 pertinent articles were included. It was highlighted that the vast majority of the individuals after suffering from COVID-19 develop a natural immunity both of cell-mediated and humoral type, which is effective over time and provides protection against both reinfection and serious illness. Vaccine-induced immunity was shown to decay faster than natural immunity. In general, the severity of the symptoms of reinfection is significantly lower than in the primary infection, with a lower degree of hospitalizations (0.06%) and an extremely low mortality.

CONCLUSIONS

this extensive narrative review regarding a vast number of articles highlighted the valuable protection induced by the natural immunity after COVID-19, which seems comparable or superior to the one induced by anti-SARS-CoV-2 vaccination. Consequently, vaccination of the unvaccinated COVID-19-recovered subjects may not be indicated. Further research is needed in order to: (a) measure the durability of immunity over time; (b) evaluate both the impacts of Omicron BA.5 on vaccinated and healed subjects and the role of hybrid immunity.

Factors Associated with the Acceptance of COVID-19 Vaccines in Citizens of Northern Peru: Cross-Sectional Study

Purpose

The presence of the COVID-19 coronavirus in Peru, and especially in northern Peru, was very fast and caused many deaths. As a result, vaccination proved to be the most immediate option to control it. However, a sector of the population was reluctant to vaccination. Therefore, this study aimed to analyze the factors associated with the acceptance of COVID-19 vaccines by citizens of northern Peru.

Patients and Methods

The study was observational, descriptive-correlational and the sample was stratified and consisted of 516 citizens from eight departments of northern Peru, who answered an online questionnaire regarding sociodemographic, cultural and health aspects. The data were analyzed using statistical tests of association and a logistic model was estimated to identify factors predicting vaccine acceptance.

Results

Among the factors associated with vaccine acceptance, sociodemographic factors such as age and family income, cultural factors such as level of knowledge, and health factors such as having another chronic disease and a vaccine with a higher confidence (p<0.05) were found. In addition, 12% of the population do not trust them, 10% are afraid that they may cause thrombosis, 13% disagree with vaccination for children, 7% think that a chip will be implanted and 8% believe that their DNA will be changed. However, most people accept vaccination and consider it necessary. A multivariate analysis was also performed for the acceptance of vaccines, which presented a percentage of 80.2% correct in the prognosis.

Conclusion

The multivariate analysis allowed a conclusion that the predictor variables for vaccine acceptance are household income of less than 1000 Peruvian soles per month, low or medium levels of knowledge, and having another chronic disease.

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A nanoparticle-based COVID-19 vaccine candidate elicits broad neutralizing antibodies and protects against SARS-CoV-2 infection

A vaccine candidate to SARS-CoV-2 was constructed by coupling the viral receptor binding domain (RBD) to the surface of the papaya mosaic virus (PapMV) nanoparticle (nano) to generate the RBD-PapMV vaccine. Immunization of mice with the coupled RBD-PapMV vaccine enhanced the antibody titers and the T-cell mediated immune response directed to the RBD antigen as compared to immunization with the non-coupled vaccine formulation (RBD + PapMV nano). Anti-RBD antibodies, generated in vaccinated animals, neutralized SARS-CoV-2 infection in vitro against the ancestral, Delta and the Omicron variants. At last, immunization of mice susceptible to the infection by SARS-CoV-2 (K18-hACE2 transgenic mice) with the RBD-PapMV vaccine induced protection to the ancestral SARS-CoV-2 infectious challenge. The induction of the broad neutralization against SARS-CoV-2 variants induced by the RBD-PapMV vaccine demonstrate the potential of the PapMV vaccine platform in the development of efficient vaccines against viral respiratory infections.

Relationship between blood clots and COVID-19 vaccines: A literature review

SARS-CoV-2 pandemic is one of the most critical pandemics during human civilization. Several therapeutic strategies for COVID-19 management have been offered; nonetheless, none of them seems to be sufficiently beneficial. In effect, vaccines have been proffered as a viable option. The critical issue now is to concentrate on protecting individuals against illness through immunization. One of the causes for concern among the researchers, physicians, and generally the whole community from the onset of vaccination has been the adverse effects (specifically blood clots) that may be observed after the injection of the COVID-19 vaccine. In some countries, such concerns have even resulted in the temporary or permanent discontinuation or abandonment of the application of some vaccines (especially AstraZeneca and Janssen). By evaluating rigorous studies published on this subject, the present article is aimed at identifying the association between blood clot incidence and COVID-19 vaccination. Various methods for producing the COVID-19 vaccines are analyzed, along with their possible pros and cons as well as common and rare side effects, especially VITT and blood clots. Finally, the differences of various vaccines on thrombotic events, WHO recommendations for VITT treatment, and blood clots statics are discussed.

Case Report: Idiopathic Subcutaneous Thrombotic Vasculopathy

Lower extremity ulcers have significant morbidity, with treatment determined by the underlying disorder. Reported is a 32-year-old female presenting with small skin nodules and bruises across her legs 4 weeks following her second COVID vaccination. These lesions progressed into large, necrotic ulcers over several months. Initial work-up showed widespread pannicular thrombotic vasculopathy with ischemic skin necrosis. The tissue was negative for calcification on Von Kossa histochemistry, and a working diagnosis of subcutaneous thrombotic vasculopathy was suggested. The ulcers progressed despite treatments with corticosteroids, therapeutic anticoagulation, intravenous immunoglobulin, plasmapheresis, sodium thiosulfate, wound care, and repeat debridement. Later debridement specimens demonstrated rare vascular and pannicular calcifications. This finding supports the hypothesis that subcutaneous thrombotic vasculopathy is a precursor to calciphylaxis, the patient’s current working diagnosis. However, based on the patient’s entire clinical picture, a definitive diagnosis has yet to be found. This report highlights the challenges of working with rare diseases and the importance of multidisciplinary cooperation.

Safety of SARS-CoV-2 vaccination in patients with Behcet’s syndrome and familial Mediterranean fever: a cross-sectional comparative study on the effects of M-RNA based and inactivated vaccine

Most of the published data relate to classical forms of rheumatic diseases (RD) and information on rare inflammatory disorders such as Behçet’s syndrome (BS) and familial Mediterranean fever (FMF) is limited. We studied the frequency of side effects and disease flares after COVID-19 vaccination with either Pfizer/BioNTech or Sinovac/CoronaVac in 256 patients with BS, 247 with FMF, and 601 with RD. Telephone interviews were conducted using a questionnaire survey in a cross-sectional design in patients with BS, FMF, and RD followed by a single university hospital. Study participants were vaccinated either with CoronaVac (BS:109, FMF: 90, and RD: 343,) or BioNTech (BS: 147, FMF: 157 and RD: 258). The majority have received double dose (BS: 94.9%, FMF 92.3% and RD: 86.2%). BioNTech ensured a significantly better efficacy than CoronaVac against COVID-19 in all patient groups (BS: 1.4% vs 10.1%; FMF: 3.2% vs 12.2%, RD:2.7% vs 6.4%). Those with at least one adverse event (AE) were significantly more frequent among those vaccinated with BioNTech than those with CoronaVac (BS: 86.4% vs 45%; FMF: 83.4% vs 53.3%; and RD: 83.3% vs 45.5%). The majority of AEs were mild to moderate and transient and this was true for either vaccine. There were also AEs that required medical attention in all study groups following CoronaVac (BS: 5.5%, FMF: 3.3%, and RD:2.9%) or BioNTech (BS: 5.4%, FMF: 1.9%, and RD: 4.7%). The main causes for medical assistance were disease flare and cardiovascular events. Patients with BS (16.0%) and FMF (17.4%) were found to flare significantly more frequently when compared to those with RD (6.0%) (p < 0.001). This was true for either vaccine. BS patients reported mainly skin-mucosa lesions; there were however, 11 (4.3%) who developed major organ attack such as uveitis, thrombosis or stroke. Flare in FMF patients were associated mainly with acute serositis with or without fever. Arthralgia/arthritis or inflammatory back pain were observed mainly in the RD group. Our study demonstrates that BS and FMF patients vaccinated with either CoronaVac or BioNTech demonstrated similar AE profile and frequency compared to RD patients. AEs that required physician consultation or hospitalization occurred in all study groups after either CoronaVac or BioNTech. Increased frequency of flares in BS and FMF compared to that seen in RD might reflect defects in innate immunity and deserves further investigation. Caution should be required when monitoring these patients after vaccination.

Case Report: Recanalization of Branch Retinal Artery Occlusion Due to Microthrombi Following the First Dose of SARS-CoV-2 mRNA Vaccination

Background: We report on a patient with a branch retinal artery occlusion (RAO) and its recanalization based on multimodal retinal and angiographic images after he was administered the first dose of the SARS-CoV-2 mRNA vaccine.

Case summary: A 64-year-old man complained of a right, painless, inferior field defect 3 days after the first dose of BNT162b2 vaccination. Fundus examination revealed decolorization of the right upper macula, including microthrombi in the superior proximal branch of the retinal artery. Optical coherence tomography angiography revealed upper macular hypoperfusion. Fluorescein angiography revealed prolonged arteriovenous transit to the macula. After paracentesis with antiplatelet medications, the artery was recanalized as the thrombi dissolved, and the right visual field was recovered. Re-occlusion did not occur during the 3 months after the second mRNA vaccination.

Conclusion: Non-embolic thrombotic RAO may develop shortly after the SARS-CoV-2 mRNA vaccine. Ophthalmologists should consider RAO as a possible post-vaccination adverse event. The temporal association between mRNA vaccination and RAO onset with evidence of microthrombi might provide additional clues to elucidate the unpredictive arterial thrombosis following SARS-CoV-2 mRNA vaccination.