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Vaccines (Basel) ; 10(10)2022 Oct 12.
Article in English | MEDLINE | ID: covidwho-2071936


BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a constantly evolving virus, resulting in an increased burden on the existing COVID-19 vaccines. Healthcare workers (HCWs) are the first line of defense against the coronavirus disease 2019 (COVID-19) pandemic and have been prioritized among the risk categories receiving the COVID-19 vaccine. This work aimed to investigate the maintenance of antibody response of the Oxford-AstraZeneca vaccine (ChAdOx1/nCoV-19). METHODS: Anti-spike immunoglobulin G (IgG) was measured at baseline point (immediately prior to vaccination) and 12- and 24-week (w) points following vaccination. Adverse reactions to the vaccine were reported. Participants were followed up for the incidence of COVID-19 during the 12 w interval between vaccination doses for 24 w after the second dose. RESULTS: A total of 255 HCWs participated in the study. Prior to vaccination, 54.1% experienced COVID-19, 88.2% were seropositive after the first dose, while seropositivity reached 95.7% after the second dose. Following the first and second doses, the anti-spike IgG serum level was significantly higher in subjects with past COVID-19 than in others (p < 0.001 and =0.001, respectively). CONCLUSIONS: The Oxford-AstraZeneca vaccine is generally safe and provides a highly effective long-term humoral immune response against the Delta and Omicron variants of SARS-CoV-2.

Travel Med Infect Dis ; 48: 102334, 2022.
Article in English | MEDLINE | ID: covidwho-1799699


BACKGROUND: It has been found that patients recovered from COVID 19 may still test Reverse Transcriptase- Polymerase Chain Reaction (RT- PCR) positive without being infectious; the reasons are unclear. The occurrence of false-negative results of RT- PCR interferes with a proper diagnosis. The objectives of that work were to determine factors associated with persistently detectable SARS-CoV-2 RNA among recovered hospitalized patients and to determine the incidence of false-negative RT-PCR results and associated factors. METHODS: Relevant data were collected from 482 COVID 19 patients hospitalized in six referral centers from four countries. RESULTS: The median duration of RT- PCR conversion to negative was 20 days. Out of 482 studied patients, 8.7% tested positive after more than four weeks and were considered prolonged convertors. Binary logistic regression analysis revealed headache as an independent risk factor for short conversion time while fever, hypertension, chronic obstructive pulmonary disease, lymphopenia, elevated erythrocyte sedimentation rate, and the number of lobes affected, and bilateralism were found to be independent risk factors for prolonged positivity. Eighteen patients had initial negative results then turned positive after 24-48 h. Associated factors and outcomes were identified. CONCLUSION: Identifying patients with a high likelihood of COVID-19 despite a negative RT-PCR is critical for effective clinical care. However, patient isolation resumption depending on positive RT-PCR despite clinical and radiological recovery is an overrating that greatly burdens the health sector.

COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , Humans , RNA, Viral , Respiratory System , Reverse Transcriptase Polymerase Chain Reaction
SSRN; 2022.
Preprint in English | SSRN | ID: ppcovidwho-329046


Objectives: To date, the world has experienced three waves of the Coronavirus disease- 19 (COVID-19) pandemic, and the fourth wave is going on. Patients infected during the third wave were the subject of this study. Objectives were to describe their clinical manifestations, to explain their laboratory and radiological findings, to conclude factors contributing to clinical outcomes, and to evaluate treatment protocols used. Methods: Relevant data were collected from patients admitted to six referral centers in four countries. Results: Data analysis identified symptomatology and variables related to acquisition and infection outcome. The commonest symptoms were cough (81.5%), body aches (74.1%), and fever (71.6%). Binary regression model revealed those to be independent risk factors for mortality;age, vomiting and epigastric pain, diabetes, obesity, oxygen saturation less than 90%, leukocytosis, neutrophilia, lymphopenia, thrombocytopenia, elevated creatinine, high glucose level, lung ground glass opacities with consolidation, affection of four lobes and bilateralism. Neither d-dimer nor lactate dehydrogenase nor ferritin foretells death possibility. The efficacy of medications used was convenient. Conclusions: Assessing the clinical features of different COVID-19 waves, identifying predictors of outcomes, and conclude the efficacy of treatment protocols provides insight into patients’ response and viral behaviors, which help in proper diagnosis and treatment of subsequent surges.