ABSTRACT
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.
Subject(s)
COVID-19 Vaccines , COVID-19 , Humans , Adult , Middle Aged , Prospective Studies , Nigeria , Tertiary Care Centers , Antibody Formation , Pandemics , Spike Glycoprotein, Coronavirus , COVID-19/prevention & control , SARS-CoV-2 , Health Personnel , Immunoglobulin G , Immunoglobulin MABSTRACT
BACKGROUND: Noise remains a nuisance which impacts negatively on the physical, social and psychological wellbeing of man. It aggravates chronic illnesses like hypertension and other cardiopulmonary diseases. Unfortunately, increased activities from industrialization and technological transfers/drifts have tumultuously led to increased noise pollution in most of our fast growing cities today and hence the need for concerted efforts in monitoring and regulating our environmental noise. OBJECTIVE: To assess the equivalent noise level (Leq) in Abuja municipality and promote a simple method for regular assessment of Leq within our environment. METHOD: This is a cross-sectional community based study of the environmental Leq of Abuja municipality conducted between January 2014 and January 2016. The city was divided into 12 segments including residential, business and market areas via the Abuja Geographic Information System. The major markets were captured separately on a different scale. Measurements were taken with the mobile phone softwares having validated this with Extech 407730 digital sound level meter, serial no Z310135. Leq(A) were measured at different points and hours of the day and night. The average Leq(A) were classified according to localities and compared with WHO standard safety levels. RESULTS: LeqD ranged 71-92dB(A); 42-79dB(A) and 69-90dB(A) in business/ parks, residential and market places respectively. The Night measurements were similar 18dB(A)-56dB(A) and the day-night Leq(A)=77.2dB(A) and 90.4dB(A) for residential and business zones. CONCLUSION: The night noise levels are satisfactory but the day and day-night levels are above the recommended tolerable values by WHO and therefore urgently call for awareness and legislative regulations.
