Adenoviral Vector-based Vaccine Research Articles

False positive findings associated with adenoviral vector-based vaccine underscore the regulatory necessity to eliminate abnormal toxicity test

Accumulating evidence has shown that the abnormal toxicity test (ATT) is not suitable as a quality control batch release test for biologics and vaccines. The purpose of the current study was to explore the optimal ATT experimental design for an adenoviral vector-based vaccine product to avoid false positive results following the standard test conditions stipulated in the Pharmacopoeias. ATT were conducted in both mice and guinea pigs based on methods in Pharmacopeias, with modifications to assess effects of dose volume and amount of virus particles (VPs). The results showed intraperitoneal (IP) dosing at human relevant dose and volume (i.e., VPs), as required by pharmacopeia study design, resulted in false positive findings not associated with extraneous contaminants of a product. Considering many gene therapy products use adeno associated virus as the platform for transgene delivery, data from this study are highly relevant in providing convincing evidence to show the ATT is inappropriate as batch release test for biologics, vaccine and gene therapy products. In conclusion, ATT, which requires unnecessary animal usage and competes for resources which otherwise can be spent on innovative medicine research, should be deleted permanently as batch release test by regulatory authorities around the world.

Aggressive Vaccine-Induced Immune Thrombocytopenia and Thrombosis in a Young Woman with a Past Mild SARS-CoV-2 Infection

Vaccine- induced immune thrombocytopenia and thrombosis (VITT) is a rare adverse event occurring after immunization with adenoviral vector-based vaccines against SARS-CoV-2. This life-threatening condition is characterized by thrombocytopenia, systemic activation of coagulation, and anti-platelet factor 4 antibodies, often resulting in extensive venous thrombosis. Arterial thrombosis is less common and mainly affects the aorta, peripheral arteries, heart, and brain. Several cases of ischemic stroke have been reported in VITT patients, frequently being associated with large vessel occlusion (LVO). Here, we present a case of aggressive VITT in a 46-year-old woman with a past mild SARS-CoV-2 infection, who was admitted with a left-middle cerebral artery (MCA) territory stroke and thrombocytopenia eight days after her first dose of the ChAdOx1 nCoV-19 vaccine. The patient developed a diffuse arterial thrombosis with concomitant thrombotic events in the intrahepatic portal branches. The patient’s clinical condition worsened rapidly due to a significant enlargement of the ischemic cerebral lesion in the left hemisphere, cerebral herniation, and incipient hydrocephalus requiring decompressive neurosurgery with an unfavorable outcome. Our observations may be indicative of a stroke variant in VITT and highlight the diverse clinical manifestations of the syndrome.

Vaccine-Induced Immune Thrombotic Thrombocytopenia: Clinicopathologic Features and New Perspectives on Anti-PF4 Antibody-Mediated Disorders.

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare yet severe adverse complication first identified during the global vaccination effort against SARS-CoV-2 infection, predominantly observed following administration of the ChAdOx1-S (Oxford-AstraZeneca) and Ad26.CoV2.S (Johnson & Johnson/Janssen) adenoviral vector-based vaccines. Unlike other anti-platelet factor 4 (PF4) antibody-mediated disorders, such as heparin-induced thrombocytopenia (HIT), VITT arises with the development of platelet-activating anti-PF4 antibodies 4-42 days post-vaccination, typically featuring thrombocytopenia and thrombosis at unusual sites. To explore the unique properties, pathogenic mechanisms, and long-term persistence of VITT antibodies in patients, in comparison with other anti-PF4 antibody-mediated disorders. This review highlights the complexity of VITT as it differs in antibody behavior and clinical presentation from other anti-PF4-mediated disorders, including the high incidence rate of cerebral venous sinus thrombosis (CVST) and the persistence of anti-PF4 antibodies, necessitating a re-evaluation of long-term patient care strategies. The nature of VITT antibodies and the underlying mechanisms triggering their production remain largely unknown. The rise in awareness and subsequent prompt recognition of VITT is paramount in reducing mortality. As vaccination campaigns continue, understanding the role of adenoviral vector-based vaccines in VITT antibody production is crucial, not only for its immediate clinical implications, but also for developing safer vaccines in the future.

COVID-19 Vaccine-induced Guillain-Barre Syndrome

Abstract First case of severe acute respiratory syndrome coronavirus-2 was detected in Wuhan province of china. Within a year, the vaccine development process accelerated and emergency approval was rolled out for vaccines. Covishield, an adenovirus vector-based vaccine manufactured by Serum Institute of India, was granted emergency use approval by the subject expert committee under Drug Controller General of India in India in the month of January. Numerous adverse effects are still under study following vaccination. Among them, a very rare complication reported is Guillain-Barre syndrome (GBS). The relation between coronavirus disease 19 (COVID-19) vaccine and GBS is still not clear. Here, we present a case of a 32-year-old female with no comorbidities, presented with complaints of bilateral weakness in lower limbs which gradually progressed to upper limbs along with bilateral facial palsy. She had taken her first shot of Covishield vaccine last month. She has no risk factors for GBS, which suggests that it was caused by the vaccine. She was admitted to intensive care unit for further management. This report might help physicians to be more vigilant in evaluating GBS cases especially in the current COVID-19 pandemic era.

Immunization against COVID-19: A Comprehensive Review on the Leading Vaccines

Abstract: The global impact of coronavirus disease (COVID-19) has prompted researchers and scientists to develop effective vaccines to contain the spread of the pandemic. This has led to the deployment of a range of vaccines from different pharmaceutical companies across the globe in a very short span of time. The current article provides a comprehensive record of all the vaccines developed against coronavirus with a specific focus on the mode of action and administration of the vaccines. The article also dwells on the composition, possible side effects and criteria for the choice of individuals for the administration of the vaccines. Vaccines against COVID-19 have been broadly categorized as mRNA vaccines, adenoviral vector-based vaccines and inactivated vaccines. Among the mRNA vaccines, the Pfizer vaccine and Moderna vaccines gained significant popularity. The Oxford Astro Zeneca vaccine and Sputnik V were the most effective viral vector vaccines. Inactivated vaccines such as Covaxin and Sinovac were also significant contributions to contain the pandemic. The review discusses the efficiency of vaccines against the variants of SARS CoV2. The review will provide a clear-cut idea about all kinds of exciting vaccines against COVID-19. At present, where the immediate crisis of the pandemic has been successfully contained, this article acts as a resource for future public health endeavors, policy makers, health care professionals and the general public to understand the diversity of COVID-19 vaccines.

Long COVID-19 Syndrome: Insights From a Major Tertiary Center in the UK on Who Is at Greater Risk.

The COVID-19 pandemic triggered the unprecedented 'long COVID' crisis, with persistent symptoms beyond two months post-infection. This study explores the nexus between long COVID symptoms, patient demographics such as age, gender, and smoking, and clinical factors like vaccination, disease severity, and comorbidities. A retrospective analysis of records was conducted between September 2021 and December 2022. The analysis covered adults with confirmed COVID-19 diagnoses. Data encompassed demographics, medical history, vaccination, disease severity, hospitalization, treatments, and post-COVID symptoms, analyzed using logistic regression. Among 289 participants, the average age was 51.51 years. Around 62.6% were females, and 93% received the COVID-19 vaccination, i.e., primarily the mRNA vaccine (48.4%) and the adenovirus vector-based vaccine (34.8%). Reinfections occurred in 11.76% of cases. Disease severity varied, with 75% having mild, 15% having moderate, and 10% having severe infections. Hospitalization rates were significant (25.6%), including 10.7% requiring intensive care. Thirteen distinct post-COVID symptoms were reported. Fatigue, shortness of breath upon exertion, and brain fog emerged as the most prevalent symptoms. Notably, females exhibited higher symptom prevalence. Significant correlations were established between higher BMI and smoking with augmented symptomatology. Conversely, a link between booster doses and symptom reduction was discerned. Using multinomial regression analysis, gender and smoking were identified as predictors of post-COVID-19 symptoms. The study underscores obesity, smoking, and the female gender's impact on long COVID symptoms; boosters show promise in alleviation. Respiratory pathology might underlie persistent symptoms in cases with radiological abnormalities and abnormal spirometry. Findings contribute to risk stratification, intervention strategies, and further research.

Seroprevalence of human adenovirus type 5 neutralizing antibodies in the Philippines.

Human adenovirus (HAdV), particularly the HAdV type 5 (HAdV-5), has been extensively utilized in the development of vector vaccines due to its high immunogenicity, good safety profile, and ease of propagation. However, one of the main challenges in its use is the presence of pre-existing immunity among vaccine recipients. Pre-existing neutralizing antibodies (NAbs) can prevent the uptake of HAdV-5 vectors and reduce vaccine efficacy. Hence, this study investigated the seroprevalence of NAbs against HAdV-5 in urban and rural regions of the Philippines. Luciferase-based neutralization assay was performed on 391 plasma/serum samples. Out of these samples, 346 or 88.5% were positive for HAdV-5 NAbs, and the majority of them (56.8%) had high titers against the virus. Among the regions included in this study, Bicol (Region V) had the highest seroprevalence rate (94.1%). Our findings show that a significant number of adults in the Philippines have pre-existing immunity against HAdV-5. This supports the recommendation that vaccination programs in the country should consider implementing vaccination techniques, such as a prime-boost regimen or addition of booster doses, to address the potential negative effects of pre-existing HAdV-5 immunity in the efficacy of adenoviral vector-based vaccines.

Cross-protection and cross-neutralization capacity of ancestral and VOC-matched SARS-CoV-2 adenoviral vector-based vaccines

COVID-19 vaccines were originally designed based on the ancestral Spike protein, but immune escape of emergent Variants of Concern (VOC) jeopardized their efficacy, warranting variant-proof vaccines. Here, we used preclinical rodent models to establish the cross-protective and cross-neutralizing capacity of adenoviral-vectored vaccines expressing VOC-matched Spike. CoroVaxG.3-D.FR, matched to Delta Plus Spike, displayed the highest levels of nAb to the matched VOC and mismatched variants. Cross-protection against viral infection in aged K18-hACE2 mice showed dramatic differences among the different vaccines. While Delta-targeted vaccines fully protected mice from a challenge with Gamma, a Gamma-based vaccine offered only partial protection to Delta challenge. Administration of CorovaxG.3-D.FR in a prime/boost regimen showed that a booster was able to increase the neutralizing capacity of the sera against all variants and fully protect aged K18-hACE2 mice against Omicron BA.1, as a BA.1-targeted vaccine did. The neutralizing capacity of the sera diminished in all cases against Omicron BA.2 and BA.5. Altogether, the data demonstrate that a booster with a vaccine based on an antigenically distant variant, such as Delta or BA.1, has the potential to protect from a wider range of SARS-CoV-2 lineages, although careful surveillance of breakthrough infections will help to evaluate combination vaccines targeting antigenically divergent variants yet to emerge.

Vaccine-Induced Immune Thrombocytopenia and Thrombosis (VITT)-Insights from Clinical Cases, In Vitro Studies and Murine Models.

An effective worldwide vaccination campaign started and is still being carried out in the face of the coronavirus disease 2019 (COVID-19) pandemic. While vaccines are great tools to confront the pandemic, predominantly adenoviral vector-based vaccines can cause a rare severe adverse effect, termed vaccine-induced immune thrombocytopenia and thrombosis (VITT), in about 1 in 100,000 vaccinated individuals. VITT is diagnosed 5-30 days post-vaccination and clinically characterized by thrombocytopenia, strongly elevated D-dimer levels, platelet-activating anti-platelet factor 4 (PF4) antibodies and thrombosis, especially at atypical sites such as the cerebral venous sinus and/or splanchnic veins. There are striking similarities between heparin-induced thrombocytopenia (HIT) and VITT. Both are caused by anti-PF4 antibodies, causing platelet and leukocyte activation which results in massive thrombo-inflammation. However, it is still to be determined why PF4 becomes immunogenic in VITT and which constituent of the vaccine triggers the immune response. As VITT-like syndromes are increasingly reported in patients shortly after viral infections, direct virus-PF4 interactions might be most relevant. Here we summarize the current information and hypotheses on the pathogenesis of VITT and address in vivo models, especially murine models for further studies on VITT.

Vaccine-Induced Immune Thrombotic Thrombocytopenia Two Years Later: Should It Still Be on the Scientific Agenda?

Vaccine-induced immune thrombotic thrombocytopenia (VITT) was recognized around 2 years ago, at the beginning of the anti-SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) vaccination campaign, as a rare but life-threatening complication of adenoviral vector vaccines. Two years later, the coronavirus disease 2019 (COVID-19) pandemic has been tamed, although not defeated, and the vaccines provoking VITT have been abandoned in most high-income countries, thus why should we still speak about VITT? Because a significant fraction of the world population has not been vaccinated yet, especially in low/middle-income countries that can only afford adenoviral vector-based vaccines, because the adenoviral vector platform is being used for the development of a large series of new vaccines for other transmissible diseases, and lastly because there are some clues suggesting that VITT may not be exclusive to anti-SARS-CoV-2 vaccines. Therefore, a deep understanding of this new syndrome is highly warranted as well as the awareness that we still miss some crucial insight into its pathophysiology and on some aspects of its management. This snapshot review aims to portray our knowledge on VITT, focusing on its clinical presentation, pathophysiological insight, diagnostic and management strategies, and to pinpoint the main unmet needs, highlighting the aspects on which research should focus in the near future.

Single-cell transcriptomic profile of hybrid immunity induced by the adenovirus vector-based vaccines Ad5-nCoV and AZD1222

Single-cell transcriptomic profile of hybrid immunity induced by the adenovirus vector-based vaccines Ad5-nCoV and AZD1222

Vaccine equity and access: A comparative assessment of Covaxin, Covishield, and Sputnik V.

The RNA virus known as SARS-CoV-2, which causes severe acute respiratory syndrome, was discovered for the first time in Wuhan, China, in December 2019. The World Health Organization (WHO) declared the outbreak a global pandemic on March 11, 2020, as a result of the virus's subsequent spread throughout the planet. The urgent creation of safe and effective vaccines has elevated to a top priority in the global healthcare industry because of the terrible effects of the COVID-19 outbreak. The Covaxin and Covishield vaccines were administered as part of the start of the SARS-CoV-2 vaccination campaign in India on January 13, 2021. Covaxin is made up of adjuvant-inactivated viral particles, whereas Covishield is an adenovirus vector-based vaccine. The utility and effectiveness of each vaccine are significantly influenced by its formulation, adjuvants, and mode of action. Vaccine efficacy depends on various factors, including the creation of memory cells, cell-mediated immunity, and antibodies. Results from third-phase trials have shown that Covishield exhibits an effectiveness of approximately 90%, while Covaxin demonstrates an effectiveness of around 80%. Both vaccines have demonstrated satisfactory efficacy against several mutant variants of SARS-CoV-2. The effectiveness of Covishield, however, should be noted as compromised if there are significant changes in the spike (S) protein structure in future variants. In contrast, Covaxin may remain effective against such variants due to its ability to elicit multiple antibodies targeting different epitopes. The objective of this study is to evaluate and contrast Covaxin, Covishield & Sputnik v immunogenic and therapeutic efficacy. Additionally, potential vaccination challenges in the coming days will be discussed. Understanding the relative strengths and limitations of these vaccines can inform decision-making and strategies related to vaccine deployment, public health interventions, and future vaccine development efforts."

Optimizing adenovirus vector-based vaccine production

Optimizing adenovirus vector-based vaccine production

An Overview of Adenovirus Vector-based Vaccines against SARS-CoV-2

Adenovirus vectors have been employed to develop a vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for curtailing the Covid-19 pandemic spreading. Many different viral vectors have been mainly targeting the SARS-CoV-2 spike (S) protein as an antigen. Spike (S) protein is comprised of S1 and S2 subunits, in which the receptor-binding domain (RBD) of S1 is responsible for recognizing and engaging with its host cellular receptor protein angiotensin-converting enzyme 2 (ACE2), S2 accounts for membrane fusion of virus and host cell. Chimpanzee adenovirus was also used as a vector vaccine for SARS-CoV-2 (ChAdSARS-CoV-2-S) by intramuscular injection, and intranasal administration has been tested. Adenovirus vector-based vaccines are the most advanced, with several vaccines receiving Emergency Use Authorization (EUA). It was shown that rhesus macaques were protected from SARS-CoV-2 challenge after a month of being vaccinated with ChAd-SARS-CoV-2-S. A single intranasal or two intramuscular ChAd-SARSCoV-2-S vaccines could induce humoral antibodies and T cell responses to protect the upper and lower respiratory tract against SARS-CoV-2. As the effectiveness was demonstrated in non-human primates, ChAd-SARS-CoV-2-Sa potential option for preventing SARS-CoV-2 infection in humans. However, detecting novel more transmissible and pathogenic SARS-CoV-2 variants added concerns about the vaccine efficacy and needs monitoring. Moreover, the cause of recently documented rare cases of vaccine indicated immune thrombotic thrombocytopenia. This review article provided details for the adenovirus vector vaccine for SARS-CoV-2 in humans and tried to provide solutions to the adenovirus vector hemagglutinin issue.

Susac syndrome following COVID-19 vaccination: a case-based review.

COVID-19 vaccine circulation approval was a turning point for the coronavirus pandemic. The current approved COVID-19 vaccines, including messenger ribonucleic acid (mRNA)-based and adenovirus vector-based vaccines, were shown to significantly reduce the disease mortality and severity, and its adverse reactions are mainly mild ones. However, few cases of autoimmune conditions, both flare-ups and new-onset, were described in association with these vaccines. Susac vasculitis (SaS) is a rare autoimmune disease characterized by the clinical triad of encephalopathy, visual disturbances, and sensorineural hearing loss. Its pathogenesis is still not fully understood but is believed to be related to autoimmune processes, including autoantibodies to anti-endothelial cells and cellular immune processes that lead to microvascular damage and, consequently, micro-occlusions of the cerebral, inner ear, and retinal vessels. It has been previously described following vaccination and, most recently, few cases following coronavirus vaccines. We here describe a case of a previously healthy 49-year-old man diagnosed with SaS 5 days following the first dose of the BNT162b2 COVID-19 vaccine.

Myopericarditis Associated with the Novavax COVID-19 Vaccine (NVX-CoV2373): A Retrospective Analysis of Individual Case Safety Reports from VigiBase.

Myocarditis and pericarditis have been associated most notably with mRNA vaccines, but the association with a recently authorized adjuvated vaccine (NVX-CoV2373) is controversial. The aim was to analyze the cases of myocarditis and pericarditis in association with NVX-CoV2373 reported to the World Health Organization (WHO) global database of individual case safety reports (ICSRs) for drug monitoring (VigiBase), applying disproportionality analyses. The main characteristics of the ICSRs reporting myopericarditis with NVX-CoV2373 have been summarized. Reporting odds ratios (RORs) as a measure of disproportionality for reported myopericarditis (November 1967-August 2022) have been calculated for NVX-CoV2373; mRNA and adenoviral vector-based vaccines were also included as a reference. In total, 61 ICSRs included NVX-CoV2373. Most of the reports originated in Australia (50; 82.0%); 24 (39.3%) were considered serious. None of them were fatal. The median age of individuals was 35.5 years old, and most were males (38; 62.3%). Chest pain was the most common co-reported event 43 (70.5%). The median induction period was 3 days after immunization. Increased disproportionality for myopericarditis was found for NVX-CoV2373 (ROR 14.47, 95% confidence interval [CI] 11.22-18.67) and mRNA vaccines: BNT162b2 (ROR 17.15, 95% CI 16.88-17.42) and mRNA-1273 (ROR 6.92, 95% CI 6.77-7.08). Higher values were found in males. The adenoviral vector-based vaccine Ad26.COV2.S showed slightly increased disproportionality (ROR 1.83, 95% CI 1.70-1.98), whereas no increased disproportionality was found for ChAdOx1. NVX-CoV2373 vaccine showed a similar increased disproportionality as mRNA vaccines. More evidence from controlled studies is necessary; however, a precautionary approach is warranted. Healthcare professionals should be aware of the potential occurrence of myopericarditis with this new vaccine.

Adenoviral Vector-Based Vaccine Platform for COVID-19: Current Status.

The coronavirus disease (COVID-19) breakout had an unimaginable worldwide effect in the 21st century, claiming millions of lives and putting a huge burden on the global economy. The potential developments in vaccine technologies following the determination of the genetic sequence of SARS-CoV-2 and the increasing global efforts to bring potential vaccines and therapeutics into the market for emergency use have provided a small bright spot to this tragic event. Several intriguing vaccine candidates have been developed using recombinant technology, genetic engineering, and other vaccine development technologies. In the last decade, a vast amount of the vaccine development process has diversified towards the usage of viral vector-based vaccines. The immune response elicited by such vaccines is comparatively higher than other approved vaccine candidates that require a booster dose to provide sufficient immune protection. The non-replicating adenoviral vectors are promising vaccine carriers for infectious diseases due to better yield, cGMP-friendly manufacturing processes, safety, better efficacy, manageable shipping, and storage procedures. As of April 2022, the WHO has approved a total of 10 vaccines around the world for COVID-19 (33 vaccines approved by at least one country), among which three candidates are adenoviral vector-based vaccines. This review sheds light on the developmental summary of all the adenoviral vector-based vaccines that are under emergency use authorization (EUA) or in the different stages of development for COVID-19 management.

Post COVID-19 Vaccine-associated Complications

The COVID-19 pandemic is being fought against worldwide; the major weapon against this pandemichas been the vaccine against it. There are reports of neurological complications and sequelae afterCOVID-19 vaccinations, some cases with ChAdOx1 nCov-19 is adenovirus vector-based vaccines. InIndia vaccination program against covid19 is using this vaccine by this vaccine. Reports of vaccineassociated side effects have emerged, which are rare but serious. This case series presents a few such cases reported in our hospitals:- RD Gardi Medical college (CR Gardi Hospital, Ujjain) and Charitable trust Hospital, Ujjain.

Immunogenicity and Safety of Vaccines against Coronavirus Disease in Actively Treated Patients with Solid Tumors: A Prospective Cohort Study.

We aimed to assess the humoral response to and reactogenicity of coronavirus disease 2019 (COVID-19) vaccination according to the vaccine type and to analyze factors associated with immunogenicity in actively treated solid cancer patients (CPs). Prospective cohorts of CPs, undergoing anticancer treatment, and healthcare workers (HCWs) were established. The participants had no history of previous COVID-19 and received either mRNA-based or adenovirus vector-based (AdV) vaccines as the primary series. Blood samples were collected before the first vaccination and after 2 weeks for each dose vaccination. Spike-specific binding antibodies (bAbs) in all participants and neutralizing antibodies (nAbs) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wild-type, Delta, and Omicron variants in CPs were analyzed and presented as the geometric mean titer. Age-matched 20 HCWs and 118 CPs were included in the analysis. The bAb seroconversion rate and antibody concentrations after the first vaccination were significantly lower in CPs than in HCWs. After the third vaccination, antibody levels in CPs with a primary series of AdV were comparable to those in HCWs, but nAb titers against the Omicron variant did not quantitatively increase in CPs with AdV vaccine as the primary series. The incidence and severity of adverse reactions post-vaccination were similar between CPs and HCWs. CPs displayed delayed humoral immune response after SARS-CoV-2 vaccination. The booster dose elicited comparable bAb concentrations between CPs and HCWs, regardless of the primary vaccine type. Neutralization against the Omicron variant was not robustly elicited following the booster dose in some CPs, implying the need for additional interventions to protect them from COVID-19.

Coagulation Parameters Among Sudanese Individuals Vaccinated with Johnson and Johnson Vaccine at Khartoum State, 2022

<i>Background: </i>A COVID 19 vaccine is a vaccine intended to provide acquired immunity against severe acute respiratory syndrome corona virus 2. Ad26.COV2.S (Johnson & Johnson) vaccine is adenovirus vector-based vaccine that targets the spike protein of the SARS-CoV-2 virus, when it enters the body it stimulates the immune response. <i>Materials and methods: </i>This was a cross sectional study, health facility base, Conducted in Vaccine centre at Omer ben Alkhatab, Khartoum, Sudan during the period July to August, 2022 to estimate changes of coagulation parameters among Sudanese vaccinated with Johnson & Johnson vaccine. Sixty samples were collected from the Participants that took the first dose of Johnson & Johnson vaccine; thirty samples before the vaccination, and thirty after vaccination. The coagulation parameters were performing by different methods. <i>Results:</i> The means of parameters before the vaccination were; APTT was (36.2 ±3), PT was (15.8±2.4), INR (1.2 ±0.2), platelets (285.9 ±7.2), fibrinogen (243.4 ±4.6) and D-dimer (0.17±0.03). The means of parameters after the vaccination for the APTT, PT, INR, platelets count, fibrinogen and the D-dimer were; (35.2 ±2.9), (13.9±2.1), (1.21±0.3), (272.8±57.9), (284.2 ±53.3) and (0.37±0.8) respectively. When compared between the results of parameters per and post vaccination the results revealed that; there was significant decrease in the time for the APTT and PTT (p value ≤0.05), in significant differences with the INR and platelets count (p value ≥0.05), significant increase for the fibrinogen and D- dimer level (p value ≤0.05). While when compared the mean of the parameters with the age, genders, and symptoms there was insignificant differences (p value ≥0.05), except the D – dimer had a significant differences with the age and symptoms (p value ≤0.05).<i> Conclusion:</i> In the conclusion of this study there was significant decrease of the activated partial thromboplastin time (APTT), Prothrombin time (PT), and significant increase in fibrinogen and D-dimer level in the Sudanese individuals after the first dose of Johnson and Johnson Vaccine.