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.

Neonatal outcomes associated with maternal recto-vaginal colonization with extended-spectrum ß-lactamase producing Enterobacteriaceae in Nigeria: a prospective, cross-sectional study.

OBJECTIVES: The objective of this study was to assess the prevalence of maternal recto-vaginal extended-spectrum ß-lactamase producing Enterobacteriacea (ESBL-E) colonization, identify risk factors for maternal and neonatal ESBL-E colonization, and subsequent impact on neonatal mortality. METHODS: A prospective, cross-sectional study was conducted at the University of Abuja Teaching Hospital from April 2016 to May 2017. Maternal-neonatal pairs were screened for ESBL-E exposure at time of delivery. Neonatal mortality was assessed at 28 days. RESULTS: A total of 1161 singleton deliveries were evaluated. In total, 9.7% (113/1161) of mothers and 4.3% (50/1161) of infants had ESBL-E-positive cultures at delivery. Maternal antibiotic exposure was associated with ESBL-E recto-vaginal colonization (18.6% (21/113) vs. 8.4% (88/1048), p < 0.001)). Maternal ESBL-E colonization (adjusted odds ratio (AOR) 14.85; 95% CI 7.83-28.15) and vaginal delivery (AOR 6.35; 95% CI 2.63-17.1) were identified as a risk factor for positive ESBL-E neonatal surface cultures. Neonatal positive ESBL-E surface cultures were a risk factor for neonatal mortality (stillbirths included, AOR 4.84; 95% CI 1.44-16.31). The finding that maternal ESBL-E recto-vaginal colonization appeared protective in regards to neonatal mortality (AOR 0.22; 95% CI .06-0.75) requires further evaluation. CONCLUSIONS: Maternal ESBL-E recto-vaginal colonization is an independent risk factor for neonatal ESBL-E colonization and neonates with positive ESBL-E surface cultures were identified as having increased risk of neonatal mortality.

Erratum: Status of Retinoids and Carotenoids and Associations with Clinical Outcomes in Maternal-Infant Pairs in Nigeria. Nutrients 2018, 10, 1286.

Due to a mistake during the production process, there were spelling errors in four of the author names in the original published version [...].

Status of Retinoids and Carotenoids and Associations with Clinical Outcomes in Maternal-Infant Pairs in Nigeria.

Vitamin A is an essential nutrient in pregnancy, and other carotenoids have been independently associated with maternal-infant outcomes. The objective of this study was to quantify the status of vitamin A and carotenoids in Nigerian maternal-infant pairs at delivery, compare these to a cohort from a developed nation, and determine the impact on clinical outcomes. Maternal and cord blood samples were collected in 99 Nigerian mother-infant pairs. Concentrations of lutein + zeaxanthin, ß-cryptoxanthin, lycopene, α- and ß-carotenes, and retinol were measured using HPLC. Descriptive statistics were calculated and Spearman coefficients were used to assess correlations between maternal and cord measurements; Mann-Whitney tests were used to compare median plasma values between dichotomous variables. Linear regression models were used to adjust for relevant confounders. A p < 0.05 was considered statistically significant. Thirty-five percent of mothers had plasma retinol concentrations ≤0.70 µmol/L; 82% of infants had plasma retinol concentrations ≤0.70 µmol/L at delivery. Maternal and infant concentrations of vitamin A compounds were highly correlated and were associated with newborn growth and Apgar scores. Despite plasma concentrations of pro-vitamin A carotenoids higher than those reported in other populations, pregnant Nigerian women have a high prevalence of vitamin A deficiency. As vitamin A related compounds are modifiable by diet, future research determining the clinical impact of these compounds is warranted.

A Comparison of Vitamin E Status and Associated Pregnancy Outcomes in Maternal⁻Infant Dyads between a Nigerian and a United States Population.

Oxidative stress is associated with adverse pregnancy outcomes, and vitamin E has powerful anti-oxidant properties with the potential to impact health outcomes. Tocopherol isomers of vitamin E differ in their ability to modulate inflammation and vary in concentration in diets containing high proportions of processed versus unprocessed foods. The purpose of this study was to compare vitamin E status and associated pregnancy outcomes (mode of delivery, chorioamnionitis, APGARs (measure of appearance, pulse, grimace, activity, respiration), gestational age at delivery, and fetal growth) between maternal⁻infant dyads in a developed and a developing nation to identify potentially modifiable differences that may impact pregnancy and neonatal outcomes and provide a way to improve maternal and neonatal health. Plasma tocopherol levels were evaluated in 189 Midwestern United States (US) mother⁻infant pairs and 99 Central Nigerian mother⁻infant pairs. Maternal and infant concentrations of α-, γ-, and δ-tocopherol were measured using HPLC with diode-array detection. Descriptive statistics were calculated and tocopherol concentrations were associated with clinical outcomes such as mode of delivery, chorioamnionitis, APGARS, and fetal growth. Alpha- and γ-tocopherol levels were higher in the US mothers, (alpha: 12,357.9 (175.23⁻34,687.75) vs. 8333.1 (1576.59⁻16,248.40) (mcg/L); p < 0.001) (gamma: 340.7 (224.59⁻4385.95) vs. 357.5 (66.36⁻1775.31) (mcg/L); p < 0.001), while δ-tocopherol levels were higher in the Nigerian mothers (delta: 261.7 (24.70⁻1324.71) vs. 368.9 (43.06⁻1886.47) (mcg/L); p < 0.001). US infants had higher γ-tocopherol levels than Nigerian infants (203.1 (42.53⁻1953.23) vs. 113.8 (0.00⁻823.00) (mcg/L); p < 0.001), while both the Nigerian mothers and infants had higher α:γ-tocopherol ratios (8.5 vs. 26.2, and 8.9 vs. 18.8, respectively; p < 0.001). Our results in both populations show associations between increased circulating γ-tocopherol and negative outcomes like Caesarian sections, in contrast to the associations with positive outcomes such as vaginal delivery seen with increased α:γ-tocopherol ratios. Growth was positively associated with α- and γ-tocopherols in cord blood in the US population, and with cord blood δ-tocopherols in the Nigerian population. Tocopherol levels likely impact health outcomes in pregnancy in a complicated metabolism across the maternal⁻fetal axis that appears to be potentially influenced by culture and available diet.

A Four-Year Retrospective Review of Very Low Birth Weight Babies Seen at the University of Abuja Teaching Hospital, Abuja, Nigeria.

AIMS AND OBJECTIVES: To review the outcome of very low birthweight infants admitted into the Special Care Baby Unit (SCBU) of University of Abuja Teaching Hospital (UATH), Gwagwalada, Abuja, Nigeria. METHODS: A retrospective review of medical records of very low birthweight (VLBW) babies seen at the SCBU of UATH over a 4-year period from April 2006 to March 2010, was undertaken. Data were obtained from patients' folders and analyzed. RESULTS: Overall survival was 60.8%. Survival of infants with birth weight below 1000 grams was 26.8% compared to 66.4% for those between 1000 and 1499 grams. The main determinants of survival were birth weight (p< 0.0001) and gestational age (p = 0.0106). Other predictors of outcome were development of features of respiratory distress syndrome within hours of delivery, recurrent apnoea, drainage of liquor of more than 18 hours before delivery, hyperkalaemia, lack of antenatal care and being born-before-arrival (outborn). CONCLUSIONS: Survival rate is low compared to values from other communities in developing countries but better than values from many centres in Nigeria. Timely and effective management of apnoea, respiratory distress syndrome and prevention of extremely low birthweight (ELBW) deliveries through adequate antenatal care are required to improve on the current survival rate.