Post COVID-19 vaccination medium vessel vasculitis: a systematic review of case reports.

PURPOSE: Vaccinations are essential in minimizing the effects of global health crises including COVID-19 pandemic. This study investigates the potential association between COVID-19 vaccination and the occurrence of medium vessel vasculitis. METHODS: Several databases were utilized to conduct a comprehensive literature review. The studies were carefully evaluated to ensure their quality and eliminate any potential bias. RESULTS: After reviewing 935 search results and removing duplicates, we selected 10 case reports. We discovered that medium vessel vasculitis may occur after COVID-19 vaccination, typically appearing around 16.2 days after vaccination. The patients in the study had a median age of 43.5 years and were predominantly males (80%). Additionally, half of the cases were reported after the second dose of vaccination. CONCLUSIONS: Vaccination-associated vasculitis is a rare yet possible complication of COVID-19 vaccination and lacks a clear treatment protocol.

Effectiveness of Heterologous Coronavirus Disease 2019 (COVID-19) Vaccine Booster Dosing in Brazilian Healthcare Workers, 2021.

BACKGROUND: Little is currently known about vaccine effectiveness (VE) for either 2 doses of Oxford-AstraZeneca (ChAdOx1) viral vector vaccine or CoronaVac (Instituto Butantan) inactivated viral vaccine followed by a third dose of mRNA vaccine (Pfizer/BioNTech) among healthcare workers (HCWs). METHODS: We conducted a retrospective cohort study among HCWs (aged ≥18 years) working in a private healthcare system in Brazil from January to December 2021. VE was defined as 1 - incidence rate ratio (IRR), with IRR determined using Poisson models with the occurrence of laboratory-confirmed coronavirus disease 2019 (COVID-19) infection as the outcome, adjusting for age, sex, and job type. We compared those receiving viral vector or inactivated viral primary series (2 doses) with those who received an mRNA booster. RESULTS: A total of 11 427 HCWs met the inclusion criteria. COVID-19 was confirmed in 31.5% of HCWs receiving 2 doses of CoronaVac vaccine versus 0.9% of HCWs receiving 2 doses of CoronaVac vaccine with mRNA booster (P < .001) and 9.8% of HCWs receiving 2 doses of ChAdOx1 vaccine versus 1% among HCWs receiving 2 doses of ChAdOx1 vaccine with mRNA booster (P < .001). In the adjusted analyses, the estimated VE was 92.0% for 2 CoronaVac vaccines plus mRNA booster and 60.2% for 2 ChAdOx1 vaccines plus mRNA booster, when compared with those with no mRNA booster. Of 246 samples screened for mutations, 191 (77.6%) were Delta variants. CONCLUSIONS: While 2 doses of ChAdOx1 or CoronaVac vaccines prevent COVID-19, the addition of a Pfizer/BioNTech booster provided significantly more protection.

The COVID-19 Humoral Immunological Status Induced by CoronaVac and AstraZeneca Vaccines Significantly Benefits from a Booster Shot with the Pfizer Vaccine.

A third vaccine dose against COVID-19 is already a reality in some countries around the world. In this study, we aimed to evaluate the effectiveness of the Brazilian immunization policy for COVID-19, which involves a booster shot. Participants (n = 210) provided serum samples, which were subjected to enzyme-linked immunosorbent assay (ELISA). Immunological profiles were defined as individuals with or without previous SARS-CoV-2 infection who received at least one vaccine dose in the immunization regimens of AstraZeneca, CoronaVac, or CoronaVac plus a booster shot with Pfizer. In addition, nonvaccinated/infected individuals were also included. As main results, we observed that the numbers of infected individuals were significantly reduced among those who were vaccinated, even with one dose. This result indicates that vaccines are highly protective against COVID-19. However, we observed a significant tendency of serum level decreases of specific antibodies over the time after the second dose. In contrast, the booster shot with the Pfizer vaccine after a CoronaVac immunization regimen showed a significant increase in the specific SARS-CoV-2 IgG serum levels. Moreover, we found that vaccination induced a significantly higher humoral immunological status than only the natural infection with SARS-CoV-2. Collectively, results presented here indicate that vaccines are necessary to induce a robust immunological status, which is maintained, restored, or even improved by booster shots. IMPORTANCE COVID-19 continues to spread around the world despite significant progress in vaccine distribution and population immunity. The dynamics of the antiviral antibody response postvaccination is critical to evaluate vaccine effectiveness across different vaccine platforms and over time. In this study, we evaluate the serum levels of antiviral antibodies in patients from Brazil that received either the CoronaVac or the AstraZeneca vaccine. We found that antibody levels wane over time, vaccines induce protective immunity, and humoral immunity is enhanced with a third vaccine dose. This study reveals that the COVID-19 humoral immunological status induced by vaccines significantly benefits from a booster shot.

Prolonged headache with vaccine- and dose-specific headache pattern associated with vaccine against SARS-CoV-2 in patients with migraine.

OBJECTIVE: To examine SARS-CoV-2 vaccine-related headache characteristics and risk factors in migraine patients. METHODS: This retrospective cohort study included 732 migraine patients who had AstraZeneca Vaxzevria, Pfizer-BioNTech Comirnaty, or Moderna Spikevax vaccines. Participants provided information through questionnaires and headache diaries. Headache frequency before and after vaccination and factors associated with headache risk were examined. RESULTS: Approximately a third of patients reported increased headache the day after having primary and booster doses, with mean increase ± SD of 1.9 ± 1.2 and 1.8 ± 1.1 days/week, respectively. Proportions of migraine patients with headache (after vaccination vs. before vaccination) increased after having primary-dose Vaxzevria (35.3% vs. 22.8%, p < 0.001) but not Spikevax (23.8% vs. 26.7%, p = 0.700) or Comirnaty (33.2% vs. 25.8%, p = 0.058). Headache proportion increased after having all three boosters (Vaxzevria 27.1% vs. 17.9% p = 0.003; Comirnaty 34.1% vs. 24.5% p = 0.009; Spikevax 35.2% vs. 24.8% p = 0.031). For primary dose with Vaxzevria and Comirnaty, headache risk increased on the vaccination day, peaked on the day after vaccination, and subsided within a week, while for Spikevax headache risk rose gradually after vaccination, peaked on the seventh post-vaccination day and subsided subsequently. For booster dose, headache risk generally increased on the vaccination day, peaked on the day after vaccination, and subsided gradually with fluctuating pattern within a month. Our study also showed that headache increased on the day before primary dose but not booster dose vaccination and it may be attributable to stress associated with having to undertake new vaccines. Multivariable analyses showed that depression was associated with headache. CONCLUSION: Prolonged headache with vaccine- and dose-specific headache pattern was found. Patients with higher risks of vaccine-related headache must be informed of the potential worsening headache.

Postmortem PF4 antibodies confirm a rare case of thrombosis thrombocytopenia syndrome associated with ChAdOx1 nCoV-19 anti-COVID vaccination.

We report a case of cerebral venous sinus thrombosis, bilateral adrenal hemorrhage, and thrombocytopenia in a 70-year-old man found dead. He had previously received the ChAdOx1 nCoV-19 vaccine (Vaxzevria®, AstraZeneca) 18 days before, and had since developed unspecific and undiagnosed characteristics of what proved to be a rare case of vaccine-associated thrombocytopenia with thrombosis syndrome (TTS). He was found dead 1 week after the beginning of symptoms (day 25 post-vaccine). Autopsy yielded venous hemorrhagic infarction with the presence of thrombi within dural venous sinuses, and extensive hemorrhagic necrosis of the central part of the adrenal glands. Antibodies against platelet factor 4 (PF4) were strongly positive in postmortem fluids, as measured with an enzyme-linked immunosorbent assay (ELISA). This difficult diagnosis is usually made during the patient's lifetime. After eliminating differential diagnoses, we concluded on a fatal case of vaccine-induced immune TTS with positive anti-PF4 antibodies in cadaveric blood, 3 weeks after ChAdOx1 nCoV-19 vaccination. Specific search for anti-PF4 antibodies in cadaveric blood appears therefore paramount to assess postmortem cases of TTS associated with anti-COVID vaccines.

Vaccine-Induced Functional Neurological Disorders in the Covid-19 Era.

The large amount of information available to the public regarding vaccines against Covid-19 coupled with pandemic stress and increased somatic attention could potentially precipitate development of functional neurological disorders (FNDs) following vaccination. A growing number of reports indicate that functional symptoms may follow Covid-19 vaccination, similar to those observed with other vaccines previously. We review previously reported cases of FND following vaccination against Covid-19 and present three additional cases. While two patients presented to the Emergency Department with functional movement disorders, one patient presented with protracted limb weakness and sensory dysfunction. The superficial resemblance to Guillain-Barré syndrome, a known but uncommon complication of vaccination prompted an extensive workup. Clinicians need to convey the diagnosis of FND in clear and unequivocal terms to facilitate institution of appropriate therapy and rehabilitation, but importantly also to dispel any doubts in the minds of the public regarding the safety of the available vaccines. Given the presence of significant vaccine hesitancy in many countries, this is critical to the success of the global immunisation effort.

Comparison of AstraZeneca and sinopharm vaccines as boosters in protection against COVID-19 infection.

BACKGROUND: As the global number of confirmed cases rises past 640 million, vaccination remains the most effective measure in controlling COVID-19. Studies have shown that two doses of vaccination can significantly reduce hospitalization and mortality rates among patients, but the effectiveness of booster doses is also important. We aimed to evaluate the role played by the type of the 3rd dose of vaccination by comparing the safety and efficacy of two common vaccination histories differing only in the 3rd received dose. METHODS: We conducted a cross-sectional study on patients with respiratory symptoms suspected of having SARS-CoV-2 infection using Real-time PCR. We also collected information on the age, gender, and type of vaccine received for the third dose. RESULTS: Out of 346 cases with respiratory symptoms, 120 cases tested positive for SARS-CoV-2 and had received two doses of Sinopharm and a different booster dose of either AZD1222 (AstraZeneca) or BIBP (Sinopharm). Among these 120 patients, vaccination with AZD1222 as a booster dose resulted in fewer symptoms compared to those vaccinated with three doses of BIBP. CONCLUSIONS: Our study demonstrates that booster doses can help reduce hospitalization and the severity of infection, and it appears that a combination of different vaccines may be effective against severe COVID-19 infection.

A prospective cohort study protocol: monitoring and surveillance of adverse events following heterologous booster doses of Oxford AstraZeneca COVID-19 vaccine in previous recipients of two doses of Sinopharm or Sputnik V vaccines in Iran.

BACKGROUND: Regarding the paucity of evidence on the side effects of the booster dose of Oxford AstraZeneca vaccine in vaccinated people with Sinopharm or Sputnik V, we aimed to set up a cohort event monitoring (CEM) study to capture adverse events occurring in individuals who will receive the booster doses of AstraZeneca (either the first or second booster dose) following being vaccinated with Sinopharm or sputnik V vaccines in Iran. METHODS: The present study is an active COVID-19 vaccine safety surveillance through an observational prospective cohort study that will be conducted in vaccination centers in Iran. The study will be conducted in twelve provinces of Iran. Study sites are vaccination centers where the AstraZeneca vaccine is administered to the cohort population. The study population includes all individuals who have received two doses of Sinopharm or Sputnik V vaccines and either the first or second booster dose of AstraZeneca according to the national guidelines for immunization in Iran in 2023. We are planning to include 30,000 eligible people in this study. Each individual will be followed up for 13 weeks after either the first or second booster dose of the AstraZeneca vaccine. Furthermore, convenience sampling is used to include participants in the present study. Participation in the study will be strictly voluntary. DISCUSSION: With the planned study we will provide a valid epidemiological evidence to improve the understanding of the safety of the booster dose of the AstraZeneca and to better evaluate the effectiveness of public health interventions. This could help policy makers in managing the COVID-19 pandemic according to scientific evidence.

A Comprehensive Analysis of COVID-19 Vaccine Discourse by Vaccine Brand on Twitter in Korea: Topic and Sentiment Analysis.

BACKGROUND: The unprecedented speed of COVID-19 vaccine development and approval has raised public concern about its safety. However, studies on public discourses and opinions on social media focusing on adverse events (AEs) related to COVID-19 vaccine are rare. OBJECTIVE: This study aimed to analyze Korean tweets about COVID-19 vaccines (Pfizer, Moderna, AstraZeneca, Janssen, and Novavax) after the vaccine rollout, explore the topics and sentiments of tweets regarding COVID-19 vaccines, and examine their changes over time. We also analyzed topics and sentiments focused on AEs related to vaccination using only tweets with terms about AEs. METHODS: We devised a sophisticated methodology consisting of 5 steps: keyword search on Twitter, data collection, data preprocessing, data analysis, and result visualization. We used the Twitter Representational State Transfer application programming interface for data collection. A total of 1,659,158 tweets were collected from February 1, 2021, to March 31, 2022. Finally, 165,984 data points were analyzed after excluding retweets, news, official announcements, advertisements, duplicates, and tweets with <2 words. We applied a variety of preprocessing techniques that are suitable for the Korean language. We ran a suite of analyses using various Python packages, such as latent Dirichlet allocation, hierarchical latent Dirichlet allocation, and sentiment analysis. RESULTS: The topics related to COVID-19 vaccines have a very large spectrum, including vaccine-related AEs, emotional reactions to vaccination, vaccine development and supply, and government vaccination policies. Among them, the top major topic was AEs related to COVID-19 vaccination. The AEs ranged from the adverse reactions listed in the safety profile (eg, myalgia, fever, fatigue, injection site pain, myocarditis or pericarditis, and thrombosis) to unlisted reactions (eg, irregular menstruation, changes in appetite and sleep, leukemia, and deaths). Our results showed a notable difference in the topics for each vaccine brand. The topics pertaining to the Pfizer vaccine mainly mentioned AEs. Negative public opinion has prevailed since the early stages of vaccination. In the sentiment analysis based on vaccine brand, the topics related to the Pfizer vaccine expressed the strongest negative sentiment. CONCLUSIONS: Considering the discrepancy between academic evidence and public opinions related to COVID-19 vaccination, the government should provide accurate information and education. Furthermore, our study suggests the need for management to correct the misinformation related to vaccine-related AEs, especially those affecting negative sentiments. This study provides valuable insights into the public discourses and opinions regarding COVID-19 vaccination.

Aortic thrombosis and acute limb ischemia after ChAdOx1 nCov-19 (Oxford-AstraZeneca) vaccination: a case of vaccine-induced thrombocytopenia and thrombosis (VITT).

INTRODUCTION: Vaccine-induced thrombocytopenia and thrombosis (VITT) is a rare but devastating adverse event associated with the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) adenoviral vaccine against the Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2). METHODS: A 49-year-old man presented to the emergency department with acute right limb ischemia (Rutherford IIB) nine days after his ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccination. CT angiography revealed significant aortic thrombosis and right femoral artery occlusion. Severe thrombocytopenia (platelet count of 23 × 103/µL), promptly elevated D-dimers (37937 ng/mL) and a reduced fibrinogen level (176 mg/dL) were remarkable. ELISA testing for anti-PF4 antibodies confirmed the diagnosis of VITT. RESULTS: An emergency revascularization of the right leg was provided via thrombectomy. High-dose intravenous immunoglobulins were administered whereafter the platelet count restored gradually. Therapeutic anticoagulation was progressively started. The postoperative course was uneventful and follow-up imaging after four weeks showed an almost complete resolution of the significant aortic thrombosis. CONCLUSION: Early recognition and appropriate counseling of VITT is advocated to pursue a good clinical outcome. Our patient presenting with severe aortic thrombosis and acute limb ischemia was successfully treated by a vascular thrombectomy along with intravenous immunoglobulins and anticoagulation therapy as the mainstay therapy.

Acute onset ocular myasthenia gravis after vaccination with the Oxford-AstraZeneca COVID-19 vaccine.

Myasthenia gravis (MG) is an autoimmune disease that results in muscle weakness and fatigability. Extraocular involvement may be the first sign of disease. It may be triggered by infections, stress, or medications. We describe a first reported case of ocular MG induced by the viral vector Oxford-AstraZeneca coronavirus disease (COVID-19) vaccine, detail the pathophysiology of vaccine-induced MG, and explore the impact of COVID-19 on MG patients.

Antibody response to Covid-19 vaccine (AstraZeneca) amongst Healthcare Workers in a Tertiary Hospital in Nigeria.

BACKGROUND: With no known cure, accelerated development of vaccines became pertinent to contain the COVID-19 pandemic. OBJECTIVES: To assess the IgG antibody response to the viral spike protein and determinants of developing IgG antibodies after vaccination with two doses of the AstraZeneca vaccine. METHODS: This was a prospective cohort study amongst healthcare workers. Serum samples were obtained before vaccination and at 4 and 12 weeks after the first and second doses of the vaccine respectively. Qualitatively testing for the presence of IgG antibodies to the viral spike protein was conducted using the Vidas SARS-CoV-2 IgG and IgM analyser while IgG antibodies were quantitatively assessed by antibody titre estimation using a stepwise two-fold serial dilution method. RESULTS: A total of 155 subjects between the ages of 25 to 64 years were studied. 85 (54.8%) had positive anti-spike IgG antibodies before vaccination. Out of the remaining 70 subjects, 87.3% and subsequently 96.2% developed IgG antibodies to the viral spike protein 4 and 8 weeks after the first and second doses of the vaccine respectively. The AstraZeneca vaccine was found to stimulate antibody response more than natural infection. Prior positive IgG antibodies from natural infection was found to boost antibody response to vaccination. The antibody titre levels rose with vaccination but waned overtime after the second dose of the vaccine. CONCLUSION: The AstraZeneca COVID-19 vaccine elicits an immunogenic IgG antibody response that is augmented by prior infection but however declines a few weeks after the second dose of the vaccine. CONTEXTE: En l'absence de remède connu, le développement accéléré de vaccins est devenu pertinent pour contenir la pandémie de COVID-19. OBJECTIFS: Évaluer la réponse des anticorps IgG à la protéine de pointe virale après vaccination avec deux doses du vaccin AstraZeneca. MÉTHODES: Il s'agissait d'une étude de cohorte prospective parmi les travailleurs de la santé. Des échantillons de sérum ont été obtenus avant la vaccination et à 4 et 12 semaines après la premier et la deuxième doses du vaccin respectivement. Des tests qualitatifs pour la présence d'anticorps IgG dirigés contre la protéine de pointe virale ont été effectués à l'aide de l'analyseur Vidas SARS-CoV-2 IgG et IgM, tandis que les anticorps IgG ont été évalués quantitativement par estimation du titre d'anticorps à l'aide d'une méthode de dilution en série en deux étapes. RÉSULTATS: Au total, 155 sujets âgés de 25 à 64 ans ont été étudiés. 85 (54,8 %) avaient des anticorps IgG anti-pic positifs avant la vaccination. Sur les 70 sujets restants, 87,3 % puis 96,2 % ont développé des anticorps IgG contre la protéine de pointe virale 4 et 8 semaines après la première et la deuxième doses du vaccin respectivement. Le vaccin AstraZeneca s'est avéré stimuler la réponse anticorps plus que l'infection naturelle. Des anticorps IgG antérieurement positifs d'une infection naturelle ont été trouvés pour stimuler la réponse des anticorps à la vaccination. Les niveaux de titre d'anticorps ont augmenté avec la vaccination mais ont cependant diminué avec le temps après la deuxième dose du vaccin. CONCLUSIONS: Le vaccinAstraZeneca COVID-19 suscite une réponse immunogène en anticorps IgG qui est augmentée par une infection antérieure mais qui décline cependant quelques semaines après la deuxième dose du vaccin. Mots clés: COVID-19, Travailleurs de la santé, Vaccination, vaccin AstraZeneca, Immunogène, Anticorps, réponse d'anticorps, Titre d'anticorps.

Are some COVID-19 vaccines better than others regarding the short-term side effects?

Controlling the pandemic is primarily achieved through vaccination against COVID-19. Although various COVID-19 vaccines are used worldwide, little is known about their safety and side effects. As a result, the objectives of this research are to identify the shortterm side effects of the different COVID-19 vaccines used in Iraq. Furthermore, exploring the association between experienced side effects and the brand of vaccine received. The current study evaluated the shortterm side effects of Pfizer, Sinopharm and AstraZeneca vaccines among healthcare workers in Iraq. The study used a questionnaire that consisted of dedicated sections to collect demographic data, the brand of COVID-19 vaccine received, the short-term side effects, and the willingness to receive a third booster dose. Regarding the post-vaccination side effects, the studied COVID-19 vaccines showed a comparable range of side effects, such as headaches, fever, muscle pain, joint pain, malaise, tenderness, redness, as well as pain at the site of vaccination. However, the Pfizer vaccine showed a higher incidence of pain and tenderness at the site of injection and fever compared to AstraZeneca and Sinopharm, respectively. On the other hand, the Sinopharm vaccine was associated with a higher occurrence of headaches, muscle pain, joint pain, and malaise in comparison to the Pfizer and AstraZeneca vaccines, respectively. In summary, the short-term side effects of the three vaccines were comparable; however, the AstraZeneca vaccine was associated with a lower risk of side effects.

Comparison of Time to Report the Side Effects after AstraZeneca and Sinopharm Vaccinations in Users of the COVID-19 Symptom Study App: A Survey in South Iran.

Background: Concerns about the side effects of SARS-CoV-2 vaccines have been raised nationwide. We aimed to compare the time to report the side effects of the Oxford-AstraZeneca and Sinopharm COVID-19 vaccines. Methods: Information on side effects of AstraZeneca and Sinopharm COVID-19 vaccines was obtained from the COVID-19 Symptom Study App affiliated with Shiraz University of Medical Science during 2021. A COX regression model with an adjusted Hazard Ratio and 95% Confidence Interval; HR (95% C.I) was reported at the significance level of < 0.05. Results: 4478 and 5555 participants received the AstraZeneca and Sinopharm vaccines, respectively; more age, history of SARS-CoV-2 infection, first vaccine dose, hypertension, and hypertension with cardiovascular disease were seen in the AstraZeneca group (P < 0.05 for all). However, the AstraZeneca group had lower immune deficiency and time to report the side effects (P < 0.05 for both). There was significantly less time to pain HR(95% C.I.); 0.50 (0.47-0.52), vertigo 0.65 (0.61-0.69), weakness 0.41 (0.38-0.44), headache 0.43 (0.39-0.74), anorexia 0.31 (0.28-0.34), nausea 0.56 (0.51-0.62), severer allergy 0.71 (0.63-0.81), general inflammation 0.27 (0.23-0.31), fever > 38oC 0.12 (0.1-0.15), eye inflammation 0.45 (0.39-0.52), diarrhea 0.85 (0.73-0.99), blurred vision 0.73 (0.61-0.86), injection site redness 0.32 (0.26-0.39), fatigue/paleness 0.53 (0.50-0.57), joint pain 0.55 (0.41-0.73), auxiliary gland inflation 0.59 (0.43-0.80), convulsions 0.30 (0.17-0.52), and severe side effects 0.3 (0.27-0.33) in the AstraZeneca group; However, skin rash 0.77 (0.57-1.05) and hospitalization 0.72 (0.21-2.55) were the same. Conclusion: Sinopharm COVID-19 vaccine recipients reported longer times to report vaccine-related side effects than AstraZeneca; due to the lack of adverse effects like hospitalization, vaccination should continue to control the pandemic; more real-population studies are needed on the long-term effects of vaccination against COVID-19.

Comparison of the immunogenicity of ChAdOx1 nCoV-19 vaccine against the wild-type and delta variants in kidney transplant recipients and healthy volunteers.

Little is known about immunogenicity after ChAdOx1 nCov-19 vaccination after transplantation. We assessed the vaccine response by antibody testing, surrogate neutralization test (sVNT) against wild-type (WT) and delta variant (DT), and T cell assay in 83 kidney transplant recipients (KTRs) and 52 healthy volunteers (HVs). For KTRs, a positive anti-RBD antibody was seen in 2.8% after one dose and 15.7% after two doses of the vaccine. After two doses, the positivity rate by sVNT was equal (4.9% each, for WT and DT) and was 13.4% by T cell response. Post two doses, KTRs had significantly lower geometric mean titer than HVs (1.93 [95% CI: 1.39-2.69] vs. 248.3 [95% CI: 203.7-302.6] BAU/ml, respectively, p < .001). Daily mycophenolate dose of ≥1000 mg significantly associated with negative seroconversion [risk ratio (RR) of 0.33, 95% CI: 0.15-0.72, p = .005]. Compared with cyclosporine, daily tacrolimus dose of ≤3 mg and >3 mg of tacrolimus significantly associated with negative seroconversion [RR = 0.38 (95% CI, 0.17-0.85, p = .018) and RR = 0.16 (95% CI, 0.37-0.73, p = .018)], respectively. The vaccine was safe and well-tolerated but the immune response after the two doses of ChAdOx1 nCov-19 vaccine in KTRs was very low.

AstraZeneca COVID-19 vaccine induces robust broadly cross-reactive antibody responses in Malawian adults previously infected with SARS-CoV-2.

BACKGROUND: Binding and neutralising anti-Spike antibodies play a key role in immune defence against SARS-CoV-2 infection. Since it is known that antibodies wane with time and new immune-evasive variants are emerging, we aimed to assess the dynamics of anti-Spike antibodies in an African adult population with prior SARS-CoV-2 infection and to determine the effect of subsequent COVID-19 vaccination. METHODS: Using a prospective cohort design, we recruited adults with prior laboratory-confirmed mild/moderate COVID-19 in Blantyre, Malawi, and followed them up for 270 days (n = 52). A subset of whom subsequently received a single dose of the AstraZeneca COVID-19 vaccine (ChAdOx nCov-19) (n = 12). We measured the serum concentrations of anti-Spike and receptor-binding domain (RBD) IgG antibodies using a Luminex-based assay. Anti-RBD antibody cross-reactivity across SARS-CoV-2 variants of concern (VOC) was measured using a haemagglutination test. A pseudovirus neutralisation assay was used to measure neutralisation titres across VOCs. Ordinary or repeated measures one-way ANOVA was used to compare log10 transformed data, with p value adjusted for multiple comparison using Sídák's or Holm-Sídák's test. RESULTS: We show that neutralising antibodies wane within 6 months post mild/moderate SARS-CoV-2 infection (30-60 days vs. 210-270 days; Log ID50 6.8 vs. 5.3, p = 0.0093). High levels of binding anti-Spike or anti-RBD antibodies in convalescent serum were associated with potent neutralisation activity against the homologous infecting strain (p < 0.0001). A single dose of the AstraZeneca COVID-19 vaccine following mild/moderate SARS-CoV-2 infection induced a 2 to 3-fold increase in anti-Spike and -RBD IgG levels 30 days post-vaccination (both, p < 0.0001). The anti-RBD IgG antibodies from these vaccinated individuals were broadly cross-reactive against multiple VOCs and had neutralisation potency against original D614G, beta, and delta variants. CONCLUSIONS: These findings show that the AstraZeneca COVID-19 vaccine is an effective booster for waning cross-variant antibody immunity after initial priming with SARS-CoV-2 infection. The potency of hybrid immunity and its potential to maximise the benefits of COVID-19 vaccines needs to be taken into consideration when formulating vaccination policies in sub-Saharan Africa, where there is still limited access to vaccine doses.

Disease severity and efficacy of homologous vaccination among patients infected with SARS-CoV-2 Delta or Omicron VOCs, compared to unvaccinated using main biomarkers.

From March 2021, various countries including Iraq issued prompted recommendations for increased COVID-19 vaccine protection in individuals especially those at risk of catching the virus (i.e., lifestyle, health sector workers, and chronic diseases). It is critically important to understand the impact of COVID-19 vaccinations with the most commonly used vaccines (Pfizer and AstraZeneca) among populations either on the severity of the disease or the transmissibility of SARS-CoV-2 variants of concern (VOCs) and in sequential waves. This study was conducted to establish the clinical severity of COVID-19 caused by Delta and Omicron SARS-CoV-2 variants among patients who either attended or were admitted to hospitals and to compare the effectiveness of Pfizer and AstraZeneca COVID-19 vaccines (single or double doses) at least to prevent hospitalizations if not eradicating the pandemic. A case-control study was done of 570 hospitalized patients; including 328 COVID-19 confirmed patients (166 males, 160 females) who received homologous vaccinations and 242 unvaccinated patients (128 males, 114 females) during the studied waves. The study showed that unvaccinated COVID-19 patients in both waves had expressed significantly a higher number and longer periods of symptoms than vaccinated ones. Additionally, there was no significant effect of vaccine types, Pfizer and AstraZeneca or vaccine shot numbers on the PCR-Ct in the last (Omicron) wave of the pandemic. However, in the previous (Delta) wave of the pandemic, fully vaccinated (double doses) COVID-19 patients had higher PCR-Ct values. Whether among vaccinated or unvaccinated patients, lower CRP levels recorded during the Omicron wave than that of the Delta wave, and regardless of the vaccine type or shot numbers, there were no significant differences between the two waves. Lower WBCs were observed in patients (vaccinated and unvaccinated) infected with the Delta variant in comparison to those infected with the Omicron variant and without any remarkable effect of the vaccine type or shot numbers. This is the first molecular and investigational study of the Delta variant and circulated Omicron in Iraq, regarding the severity of these two waves of SARS-CoV-2 pandemic and the efficacy of homologous vaccination, indicating the insufficiency of two doses and the demand for booster dose(s) as the most effective way of keeping on the safe-side against SARS-CoV-2.

Evaluation of response to different COVID-19 vaccines in vaccinated healthcare workers in a single center in Iran.

Due to the recent coronavirus disease 2019 (COVID-19) pandemic and emergent administration of various vaccines worldwide, comprehensive studies on the different aspects of vaccines are in demand. This study evaluated antibody response after the second dose of the COVID-19 vaccine in the Children's Medical Center personnel. The blood samples of 174 healthcare workers were gathered at least 10 days after vaccination. The administered vaccines included Oxford/AstraZeneca, COVAXIN, Sinopharm, and Sputnik V. This study assessed all antibodies employing ELISA methods, including anti-SARS-CoV-2 neutralizing antibody by DiaZist and Pishtazteb kits, anti-SARS-CoV-2-nucleocapsid by Pishtazteb kit, and anti-SARS-CoV-2-Spike by Razi kit. The cutoff for the tests' results was calculated according to the instructions of each kit. Totally, 174 individuals with an average age of 40 ± 9 years participated in this study, the proportion of men was 31%, and the frequency of past COVID-19 infection was 66 (38%). Sixteen (9%) personnel received Oxford/AstraZeneca, 28 (16%) COVAXIN, 29 (17%) Sinopharm, and 101 (58%) Sputnik V. anti-SARS-CoV-2-nucleocapsid and anti-SARS-CoV-2-Spike were positive in 37 (21%), and 163 (94%) participants and their mean level were more in adenoviral-vectored vaccines (p value < 0.0001). Neutralizing antibody was positive in 74% using Pishtazteb kit while 87% using DiaZist kit. All antibodies' levels were significantly higher in those with a past COVID-19 infection (p value < 0.0001). In conclusion, Oxford/AstraZeneca and Sputnik V had a similar outcome of inducing high levels of anti-SARS-Cov-2-spike and neutralizing antibodies, which were more than Sinopharm and COVAXIN. The titers of Anti-SARS-CoV-2-nucleocapsid antibody were low in all of these four vaccines.

Heterologous COVID-19 Vaccination in Spain: A Case Study of Individual Autonomy in the Real World.

In Spain, 1.5 million essential < 60-year-old workers were vaccinated with a first AstraZeneca vaccine dose. After assessing the cases of thrombosis with thrombocytopenia associated to this vaccine, the European Medicines Agency (EMA) supported the administration of 2 doses of the AstraZeneca vaccine with no age restrictions. Nevertheless, Spain decided not to administer the second dose of this vaccine to < 60-year-olds. The government sponsored a clinical trial (CombiVacS) to assess the immunogenicity response to a Pfizer/BioNTech vaccine dose in adults primed with the AstraZeneca vaccine. The positive results backed the Public Health Commission and the Spanish Ministry of Health to offer the Pfizer/BioNTech vaccine as the booster. Nevertheless, regional public health authorities-responsible for administering vaccines-believed that, following the EMA's decision, an AstraZeneca booster dose should be given. The public confrontation of these 2 positions forced the Spanish Health Ministry to request the signature of an informed consent form to those individuals willing to receive the AstraZeneca vaccine booster and rejecting the Pfizer/BioNTech vaccine dose. Eventually, it was decided that these essential workers could choose the vaccine but signing an informed consent form. All relevant information was posted on the Ministry of Health and regional health authorities' websites and provided to potential vaccine recipients at vaccination sites. Most individuals (≥ 75%) chose the AstraZeneca vaccine: perhaps because they likely trusted the EMA more than the CombiVacS results. This unprecedented and massive exercise of individual autonomy about the choice of COVID-19 vaccines from 2 different platforms has shown that adequately informed persons can autonomously weigh their options, regardless of government decisions. Exercising individual autonomy may contribute to the success of future COVID-19 booster vaccination campaigns.

Adverse Events following AstraZeneca COVID-19 Vaccine in Saudi Arabia: A Cross-Sectional Study among Healthcare and Nonhealthcare Workers.

INTRODUCTION: Many COVID-19 vaccines have been emerging with different efficacy and safety profiles. So far, very little attention has been paid to severity and reactogenicity of COVID-19 vaccine among healthcare workers. Thus, the aim of this study is to investigate the side effects associated with the first dose of AstraZeneca COVID-19 vaccine among healthcare workers (HCWs) and nonhealthcare workers (non-HCWs). METHOD: This is an observational cross-sectional study conducted at King Abdullah bin AbdulAziz University Hospital, Saudi Arabia, between February 28 and March 12, 2021. The major outcomes were the reported side effects of day 1, day 2, and day 3 after vaccination among HCWs and non-HCWs. Other outcomes included the onset and the duration of the reactions or the side effects that were reported. RESULTS: A total of 526 participants completed the survey with 173 (32.8%) HCWs and the remaining majority were non-HCWs. Some of the most frequently reported side effects among the participants on the first day were muscle aches (49%), followed by fever (42%) and headache (40%). HCWs experienced more muscle aches, headache, sore throat, and abdominal pain, which were statically significant, compared to non-HCWs. The mean onset of symptoms was 16 (±15.3) h in the HCW arm compared with 12.2 (±10.2) h in non-HCWs (p = 0.0024). Furthermore, the mean duration of symptoms in the HCW group was 37 (±19) h compared with 32.3 (±13) h in the non-HCW group (p = 0.067). CONCLUSION: The reported side effects were common but not pressing in both groups. HCW respondents appeared to have more COVID-19 vaccine-associated symptoms.