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.

Blood Group Distribution among COVID-19 Patients in a Nigerian Treatment Centre.

BACKGROUND: Biomarkers of susceptibility to COVID-19 are being investigated by many scientists all over the world. The ABO blood group antigens are the most frequently studied genetic markers. Reports from China and USA have shown that people with blood group A are more susceptible to COVID- 19 while those with blood group O are least susceptible. METHODS: The ABO blood group of 51 patients with COVID-19 admitted at the University of Abuja Teaching Hospital, Nigeria was determined and compared with the ABO blood group distribution in the general population. RESULTS: Out of the 51 patients, 39 (76.5%) were males and 12 (23.5%) were females, giving a male: female ratio of 3.25:1. Out of the 51 patients, 29 (56.9%) had blood group O, 12 (23.5%) had blood group A, 10 (19.6%) had blood group B and none (0%) had blood group AB. This blood group distribution was comparable to the blood group distribution in the general population. CONCLUSION: Preliminary analysis of the blood group distribution of COVID-19 patients being managed at the University of Abuja Teaching Hospital in Nigeria found no relationship between COVID-19 and ABO blood group. More studies are needed particularly in Africa to determine if ABO blood group can be a biomarker of susceptibility to COVID-19 among Africans.

CONTEXTE: Les biomarqueurs de sensibilité au COVID-19 sont étudiés par de nombreux scientifiques du monde entier. Les antigènes des groupes sanguins ABO sont les marqueurs génétiques les plus fréquemment étudiés. Des rapports de Chine et des États-Unis ont montré que les personnes du groupe sanguin A sont plus sensibles au COVID-19 tandis que celles du groupe sanguin O sont les moins sensibles. MÉTHODES: Le groupe sanguin ABO de 51 patients atteints de COVID 19 admis à l'hôpital universitaire d'Abuja, au Nigéria, a été déterminé et comparé à la distribution des groupes sanguins ABO dans la population générale. RÉSULTATS: Sur les 51 patients, 39 (76,5%) étaient des hommes et 12 (23,5%) étaient des femmes, ce qui donne un rapport homme: femme de 3,25: 1. Sur les 51 patients, 29 (56,9%) avaient le groupe sanguin O, 12 (23,5%) avaient le groupe sanguin A, 10 (19,6%) avaient le groupe sanguin B et aucun (0%) n'avait le groupe sanguin AB. Cette distribution des groupes sanguins était comparable à la distribution des groupes sanguins dans la population générale. CONCLUSION: Une analyse préliminaire de la distribution des groupes sanguins des patients COVID-19 pris en charge à l'hôpital universitaire d'Abuja au Nigéria n'a trouvé aucune relation entre le groupe sanguin COVID-19 et ABO. D'autres études sont nécessaires, en particulier en Afrique, pour déterminer si le groupe sanguin ABO peut être un biomarqueur de la sensibilité au COVID-19 chez les Africains. MOTS CLÉS: Groupe sanguin ABO, COVID-19, biomarqueur.

Post-renal transplant infections: single-center experience from Nigeria.

BACKGROUND: Infections are the leading cause of hospitalization and mortality in transplant recipients. Nigeria has a growing number of renal transplant recipients. The aim of this study was to determine the pattern of infections in renal allograft recipients in one of the major renal transplant centers in Nigeria. METHODS: All case records of renal allograft recipients on follow-up were retrieved. Those that had infection at any time after transplantation were selected. Demographic and clinical information was collected and analyzed. RESULTS: Thirty-three case records were analyzed, out of which 24/33 (72.7%) were males, with a mean age of 42.3 years (± 7.38). The median duration of developing infection post transplant was 270 days (range 2-2190). Most of the infections occurred after 6 months in 15/33 (45.5%). Urinary tract infection was the most common infection, noted in 13/33 (39.4%), followed by pneumonia, which was seen in 12 (33.3%), 9/12 (75%) of which were culture-positive. There were 2 cases (5.6%) of tuberculosis and 1 case (2.8%) of cytomegalovirus colitis. Out of the 9 culture-positive pneumonia cases, 6 (66.7%) were caused by gram-negative pathogens, with Pseudomonas aeruginosa being the most common isolate seen in 3/9 (33.3%) of the patients. Among those with urinary tract infection, Escherichia coli and Klebsiella species were isolated with equal proportion in 3/13 (23.1%), while Enterococcus faecalis was the most common isolate in 4/13 (30.8%). Overall infection-related mortality was 10/33 (30.3%), out of which 5/10 (50%) of deaths were from pneumonia. CONCLUSION: Post-transplant infection surveillance must be strengthened. The role of multidrug-resistant gram-negative bacteria in post-renal transplant infection in Nigeria needs to be evaluated.

Widespread antibiotic resistance in savannah Nigeria.

There is minimal data on antibiotic resistance from savannah northern Nigeria. A retrospective study of 438 patients seen in 12 months (2000) with microbial pathogens from urinary and respiratory tracts was undertaken. Antibiotic susceptibilities were determined using stokes disc diffusion technique. Resistance in Escherichia coli (E. coli) reached 91-96% to cotrimoxazole, tetracycline and ampicillin but was 11%, 17% and 28% to colistin, nitrofurantoin and nalidixic acid. Resistance of other uropathogens (Klebsiella and Proteus spp) reached 83-99% to cotrimoxazole, tetracycline and ampicillin but was 14-40% to colistin, nitrofurantoin and nalidixic acid. Pneumococci were non-susceptible to penicillin (93%), cotrimoxazole (92%), tetracycline (84%), ampicillin (53%), chloramphenicol (21%) and cefazolin (8%). Antibiotic resistance is widespread in savannah northern Nigeria. Resistance is less to chloramphenicol, colistin, nalidixic acid, nitrofurantoin and the latter generation cephalosporins and quinolones than to penicillin, ampicillin, cotrimoxazole and tetracycline.