These indicators show a very disparate SARS-CoV-2 exposure across communities and suggest that naturally acquired herd immunity is yet to be achieved worldwide. and 28.6% (neutralizing antibodies). In this African context, one-third (1/3) of the screened populace was exposed to SARS-CoV-2 and three-quarter (3/4) of those exposed individuals developed neutralizing antibodies against SARS-CoV-2. This data suggest that herd immunity is not yet to be achieved in Gabon. Keywords:SARS-CoV-2, Antibodies, Infants, Children, Adults == Introduction == The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19 is usually spreading around the globe. Many countries, if not all, are now facing this pandemic. Data shows that all continents and countries are not equivalent, and have GNE-8505 in some aspects, their COVID-19 epidemic profiles [13]. The main argument for Africas resilience has been the younger age of its populace. We need to understand why the computer virus spreads at different speeds and affects populations differently. To understand why the computer virus affects populations differently, and assess if SARS-CoV-2 herd immunity should be contemplated naturally or as a result of wide-scale vaccination programs [4], there is a need to conduct sero-epidemiological investigations. In Gabon, more than 200 000 subjects were screened for SARS-CoV-2 contamination (by PCR) from your 13th of March- when the first COVID-19 case was reported- to October 2020. The PCR based prevalence of SARS-Cov-2 was 4.4% with a death rate among detected cases of 0.6% (country data). The median age in Gabon is around 20 years aged, with more than 60% of the population under 25 years aged. It is in that context that Mouse monoclonal to Plasma kallikrein3 an age-stratified sero-epidemiological study was conducted to determine the extent of SARS-CoV-2 exposure in parts of the population. More precisely we decided the prevalence of anti-SARS-CoV-2 nucleocapsid (N)-protein antibodies and anti-SARS-CoV-2 spike (S)-protein antibodies in Gabonese infants, children and adults. == Main text == GNE-8505 == Methods == A prospective study was conducted from July to October 2020 in the setting of the GNE-8505 Mother and Child University or college Hospital (CHUMEJE) in Libreville to establish the prevalence of anti-SARS-CoV-2 antibodies by demographic strata. The approach consisted of screening serum from routine activities. The detection of anti-SARS-CoV-2 antibodies were carried out using two assessments. The first test was the ElecsysAnti-SARS-CoV-2 immunoassay (Roche Diagnostics, France). The Roche test detects pre-dominantly IgG, but also IgA and IgM to SARS-CoV-2 N-protein with a sensitivity of 99.5% and a specificity of 99.8%)). The second test was the VIDASSARS-COV-2 IgM/IgG test targeting the Spike protein subdomain (S1/RBD) with a GNE-8505 manufacturer declared sensitivity of 96.4100% and a specificity of 100% (Biomerieux, France). Both assessments cutoff index (COI) was one. Assays were conducted following the manufacturers’ strict instructions. The hospital table approved the study, and samples from consenting participants were selected for analysis. Consent was informed and obtained in a written or verbal format (both types are allowed) based on participant preferences. == Results == One thousand, four hundred and ninety five people were included in the study: 110 infants aged 9 months and below (7.4%), 141 children between the age of 1 1 and 5 years old (9.4%), 143 children aged between 6 and 17 years old (9.6%), 993 women aged between 18 and 85 years old (66.5%) and 108 men aged between 18 and 78 years old (7.2%). The overall prevalence of anti-SARS-CoV-2 antibodies was 36.2%. 27.7% of people developed both anti-SARS-CoV-2 nucleocapsid (N)-protein antibodies and anti-SARS-CoV-2 spike (S)-protein antibodies. Anti-SARS-CoV-2 antibodies prevalence in infants (09 months), children (117 years), and adults (men and women) were relatively the same, ranging between 33 and 37% (all antibody types) and between 25 and 28.6% (both anti-N-protein and anti-S-protein antibodies). Our analysis also showed that 76.4% of anti-SARS-CoV-2 antibody-positive subjects experienced both anti-SARS-CoV-2 N-protein antibodies and anti-SARS-CoV-2 S-protein antibodies. 22.4% of subjects positive for anti-SARS-CoV-2 antibody-positive experienced only anti-SARS-CoV-2 N-protein antibodies and 1.2% GNE-8505 of subjects positive for anti-SARS-CoV-2 antibody-positive experienced only anti-SARS-CoV-2 S-protein antibodies. The Chi-square test of significance showed no differences in immunization status by gender or by age groups. Table1shows the prevalence of anti-SARS-CoV-2 antibodies in the analyzed populations. == Table 1. == Age and gender stratified prevalence of anti-SARS-CoV-2 antibodies N = quantity of participants; % percentage of participants (prevalence) == Conversation == Similar to the study by Anand et al., our study used blood collected as part of routine medical care, limiting selection bias [5]. Libreville is the epi-centre of SARS-CoV-2 contamination in Gabon, concentrating 72% of cases (country data). In our analysis of.