Health Providers’ Points of View on the Impact of the Project to Strengthen the Expanded Program of Routine Vaccination from 2014 to 2018 in the Barumbu Health Zone in Kinshasa, Democratic Republic of Congo

According to the World Health Organization, approximately 3 million deaths are prevented each year in the world thanks to vaccination and then, in addition, each year, it makes it possible to avoid nearly 750,000 children suffering from serious physical, mental or neurological handicaps and 1.5 million other deaths could be avoided if the vaccination coverage is improved. However, vaccination coverage is often not achieved due to various difficulties encountered by health providers in the expanded program on vaccination activities. Yet, it is important to strengthen the program. This research paper aimed to assess health providers’ points of view on the impact of the project to strengthen the routine expanded program on vaccination in the Barumbu health zone in Kinshasa, Democratic Republic of Congo (RDC). To do so, we surveyed a convenience sample of 234 health providers involved in the implementation of the project, including 210 community relays, 9 permanent nurses, 9 health committee chairpersons and 6 health authorities. A questionnaire related to the objective of the research was submitted to them. After analyzing the data, we found that the points of view of health providers are negative. The performance of the vaccination program was not great. Several reasons were given for this, including the non-involvement of the political and administrative authorities, the failure to respect the funds disbursement circuit and the non-effective financing of vaccination activities in the Barumbu health zone in Kinshasa, DRC.

A Prospective Study on Evaluating the Long-Term Effects of Childhood Vaccination from Birth to 13 Years Old in Kuwait

Background: To prevent infectious diseases and deaths of children, vaccinations play a crucial role in public health strategies in Kuwait. However, it remained uncertain to demonstrate the potential long-term health outcomes of vaccination, including neurodevelopmental disorders (NDD) and autism. This study aimed to evaluate the long-term health outcomes of vaccination among Kuwait children from birth to thirteen years old. Objectives: This study included the significant objectives: (1) to compare long-term health effects, including chronic and acute conditions for unvaccinated, partially vaccinated, and vaccinated children, and (2) to evaluate the association of vaccination with the neurodevelopmental disorders (NDD) and autism, and the preventable illnesses. Methods: This prospective study involved a sample of 976 children from Kuwait based on mothers’ reporting. Data collection about the vaccination status of children and various health outcomes relevant to chronic and acute illnesses was performed based on structured questionnaires through an online survey. However, participants were classified into unvaccinated (n = 40), partially vaccinated (n = 222), and fully vaccinated (n = 714). Statistical analyses, including the chi-square test, Odds Ratios (OR), 95% Confidence Interval (CI), and logistic regression, were performed using SAS (Version 9.4) to determine the associations between vaccination status and health outcomes among children. Results: The study disclosed that vaccinated children showed an increased diagnosis of chronic (allergic rhinitis, allergies, autism spectrum, eczema, neuro-developmental disorders, learning disability, ADHD, and any chronic condition) and acute (whooping cough, pneumonia, rubella, hepatitis A or B, measles, mumps, meningitis, influenza, rotavirus, cancer, chronic fatigue, Crohn’s disease, inflammatory bowel disease, conduct disorder, diabetes type 1 or 2, rheumatoid arthritis, obesity, seizures, hearing loss, polio, diphtheria, tetanus, and depression) illnesses than unvaccinated children. The fully vaccinated children showed an increased prevalence of influenza diagnosis, while partially vaccinated children were more likely to be diagnosed with rheumatoid arthritis than unvaccinated children. In contrast, unvaccinated were more likely to have been diagnosed with chickenpox and encephalopathy than fully and partially vaccinated. Males with chronic and acute conditions had a lower incidence of allergies and pneumonia, respectively, whereas females had a reduced prevalence of acute illnesses, such as whooping cough, inflammatory bowel disease, and hepatitis A or B among vaccinated (n = 936;combination of partially vaccinated and fully vaccinated) children. Regarding medication use and health service applications, vaccinated children were more likely to use medications for fever, antibiotics, and allergies. In addition, they showed an increased rate of sick visits and emergency visits in the past twelve months. On the other hand, factors like age (2 - 5 years, 6 - 9 years, and 10 - 13 years), birth type (cesarian), and mother suffering during pregnancy (gestational diabetes) were significantly associated with NDD (learning disability, autism spectrum, and attention deficient hyperactivity disorder) in the adjusted analysis. In the interaction model of age and birth type, age (6 - 9 years;OR 5.3, 95% CI: 1.1, 25.3) and mother suffering (gestational diabetes;OR 2.5, 95% CI: 1.2, 5.2) during pregnancy were associated with NDD. Conclusion: The findings of this study showed that there are some cases where the infection rate is higher among the vaccinated compared to unvaccinated children, or there are no significant differences between the two groups in Kuwait. Upon controlling the factors in the interaction model, the age of 6 to 9 years and gestational diabetic mothers during pregnancy were associated with the synergistic increment of odds with NDD. These data findings are recommended to verify a larger and diverse group of samples to optimize the vaccination on health outcomes in Kuwait children.

Revaccination after Acute Kidney Injury Associated with Prior COVID-19 Vaccination: Case Report

Background: Acute kidney injury associated with proteinuria has been reported following vaccination against SARS-CoV-2 several times since 2021. Decisions about subsequent revaccination in these patients have been difficult because of the uncertainty of the consequences of doing so, and the absence of publications to help determine whether revaccination may be considered safe or not. Purpose: We present a case report of a 59-year-old Canadian man who developed severe acute kidney injury associated with moderate proteinuria following his first COVID-19 vaccine with the Moderna vaccine (an mRNA vaccine). He required haemodialysis for 2 weeks, which was initiated when his creatinine reached 1002 μmol/l. A kidney biopsy showed changes consistent with acute tubular necrosis. The patient was cautioned that repeat vaccination might result in further kidney injury which might be irreversible. However, he badly wanted to attempt a second COVID-19 vaccination, to facilitate a family vacation across several countries in Europe, at a time when travel restrictions were in place in many countries for persons who had not completed a course of vaccines. Method: Following deliberations, the patient chose to try a different type of Covid-19 vaccine. On this occasion, he was vaccinated with the Novavax vaccine (a subunit COVID-19 vaccine). Following this, close monitoring of his urine to detect proteinuria and blood testing for acute kidney injury were carried out on days 1, 3, 7, and 60 after vaccination. Furthermore, a year after his repeat vaccination, his kidney function and urinalysis were again assessed. Result and Conclusions: The patient did not develop acute kidney injury or worsening proteinuria following repeat vaccination. It remains unclear if acute kidney injury with proteinuria is caused by Covid-19 vaccination, or simply an incidental association. This case report suggests that it is may be reasonable for patients with acute kidney injury after COVID-19 vaccination to consider trying a different type of vaccine. In situations where a new virulent strain of virus emerges or in patients at risk of severe complication from infection, it may be reasonable to consider revaccination following appropriate counselling with close monitoring of renal function.

Survey Analysis of Influenza Vaccination Status Among Children Aged 0-6 Years

Objective:This study aims to investigate the influenza vaccination status of children aged 0-6 years in Changzhi City and to analyze its influencing factors.Methods:A questionnaire was distributed to 228 randomly selected parents of children aged 0-6 in Changzhi City to investigate the children’s influenza vaccination status.Results:(1)A total of 217 valid questionnaires were collected in this survey,with a response rate of 95.2%.(2)The results showed that the main reasons affecting children’s influenza vaccination were,in order,worrying about the safety of the influenza vaccine,believing that influenza vaccination was not necessary,and not knowing the time of the vaccination.(3)Multivariate logistic regression analysis showed that compared with children aged 0-2 years old,those aged 2-4 years old(OR=0.121,95%CI=0.032-0.301)and 4-6 years old(OR=0.385,95%CI=0.228-0.530)had lower cumulative influenza vaccination rates.Compared to the group with parental awareness of flu vaccines,the moderate awareness group(OR=2.319,95%CI=1.527-3.015)and the high awareness group(OR=2.932,95%CI=1.598-4.966)exhibited higher cumulative influenza vaccination rates among children.Parents acquire knowledge about influenza and its vaccines through vaccination centers(OR=1.396,95%CI=1.049-2.050)and doctors(OR=1.763,95%CI=1.291-2.774),which serves as a facilitating factor for influenza vaccination among 0-6-year-old children in Changzhi urban area.Conclusion:The age of the child,parental knowledge of the influenza vaccine,and parental communication with the vaccination center and the physician at the visit were the main influencing factors for influenza vaccination.

Control of highly pathogenic avian influenza through vaccination

The stamping-out strategy has been used to control highly pathogenic avian influenza viruses in many countries,driven by the belief that vaccination would not be successful against such viruses and fears that avian influenza virus in vaccinated birds would evolve more rapidly and pose a greater risk to humans.In this review,we summarize the successes in controlling highly pathogenic avian influenza in China and make suggestions regarding the requirements for vaccine selection and effectiveness.In addition,we present evidence that vaccination of poultry not only eliminates human infection with avian influenza virus,but also significantly reduces and abolishes some harmful characteristics of avian influenza virus.

Design of low-alloying and high-performance solid solution-strengthened copper alloys with element substitution for sustainable development

Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-speed rail contact wires,electronic component connectors,and other devices.Overcoming the contradiction between low alloying and high performance is an important challenge in the development of solid solution-strengthened copper alloys.Taking the typical solid solution-strengthened alloy Cu-4Zn-1Sn as the research object,we proposed using the element In to replace Zn and Sn to achieve low alloying in this work.Two new alloys,Cu-1.5Zn-1Sn-0.4In and Cu-1.5Zn-0.9Sn-0.6In,were designed and prepared.The total weight percentage content of alloying elements decreased by 43%and 41%,respectively,while the product of ultimate tensile strength(UTS)and electrical conductivity(EC)of the annealed state increased by 14%and 15%.After cold rolling with a 90%reduction,the UTS of the two new alloys reached 576 and 627MPa,respectively,the EC was 44.9%IACS and 42.0%IACS,and the product of UTS and EC(UTS×EC)was 97%and 99%higher than that of the annealed state alloy.The dislocations proliferated greatly in cold-rolled alloys,and the strengthening effects of dislocations reached 332 and 356 MPa,respectively,which is the main reason for the considerable improvement in mechanical properties.

COVID-19 Vaccination Uptake and Associated Factors in Selected Communities in Two Southwestern States in Nigeria

Introduction: COVID-19 vaccine uptake and acceptance have been a major global concern due to the prevalent misinformation and disinformation that has characterized the vaccine rollout worldwide. This study aimed to assess COVID-19 vaccine uptake and acceptance, and associated factors among selected community members in two states in southwestern Nigeria. Method: We conducted a cross-sectional study using a multistage sampling technique. Fifty catchment settlements of 10 health facilities in each of Oyo and Ogun States targeted for a COVID-19 infection prevention and control intervention were randomly selected. Four households were targeted per settlement. All households that refused access were replaced, to ensure a minimum of four households randomly selected per settlement. The primary household decision-maker was interviewed in each household. Information elicited included respondents’ sociodemographic characteristics, health history, knowledge, risk and benefit perception about the COVID-19 vaccine, vaccine uptake, and willingness to be vaccinated. The study was conducted from July–August 2021. Data were analyzed using SPSS IBM version 23. Result: Four hundred household decision-makers were surveyed in Oyo and Ogun states, after replacement. The mean age of the respondents was 43.0 ± 11.0 years. The majority, 346 (86.5%) had heard about COVID-19 vaccination, but only 47 (13.6%) had received a COVID-19 vaccination. Of the 299 respondents who reported not receiving a COVID-19 vaccination, 166 (55.5%) were willing to be vaccinated. In univariate analysis, respondents who were female had tertiary education, perceived that COVID-19 vaccines are free and accessible, perceived that COVID-19 vaccines have minimal side effects, and perceived higher benefits of COVID-19 vaccination had higher odds of being vaccinated. In contrast, younger respondents, respondents with higher knowledge scores on COVID-19 preventive measures, and with chronic illness had lower likelihoods of being vaccinated. In multivariate analysis, only the respondent’s age, perception score on COVID-19 vaccine benefits, knowledge score on IPC measures, and positive response on accessibility and safety were significant after adjusting for other factors. Conclusion: COVID-19 vaccine uptake rate as well as willingness to receive vaccination were low in the study setting. There is an urgent need for policymakers to embark on well-designed campaigns to address barriers to COVID-19 vaccination to increase vaccine uptake.

COVID-19 Vaccination Status and Severe Outcomes among Patients Hospitalized for COVID-19 in West Africa, Togo, 2021

Objectives: More than a year after its introduction, COVID-19 vaccination coverage was low in the Togolese population and little data were available on its benefits for hospitalized patients. This study aimed to describe the impact of COVID-19 vaccination on the prognosis of hospitalized patients. Methods: This was a retrospective cohort study of patients admitted to the Centre Hospitalier Régional Lomé Commune (Togo) between June 1, 2021 and May 31, 2022. Primary outcomes (admission to the intensive care unit and death) were presented with frequency and proportion. Mortality rates were presented by sociodemographic and clinical characteristics and compared by appropriate statistical tests. Factors associated with inpatient death were described by performing a Cox proportional hazard regression. Results: A total of 604 patients were hospitalized (50.0% women). The mean age was 54.03 ±17.1 years. Only 55 patients were fully vaccinated (9.1%). ICU admission was significantly more frequent in unvaccinated patients than in vaccinated ones (63.0% vs. 38.2%;p Conclusion: COVID-19 vaccination had a significant benefit for patients with COVID-19 infection in terms of reducing the risk of death. Based on real-world data from sub-Saharan Africa, this information can help optimize the benefit of COVID-19 vaccination by raising community awareness and increasing vaccine coverage while reducing hesitancy.

Evaluation of COVID-19 Cases and Vaccinations in the State of Georgia, United States: A Spatial Perspective

This study evaluates the distribution of COVID-19 cases and mass vaccination campaigns from January 2020 to April 2023. There are over 235,000 COVID-19 cases and over 733,000 vaccinations across the 159 counties in the state of Georgia. Data on COVID-19 was acquired from usafact.org while the vaccination records were obtained from COVID-19 vaccination tracker. The spatial patterns across the counties were analyzed using spatial statistical techniques which include both global and local spatial autocorrelation. The study further evaluates the effect of vaccination and selected socio-economic predictors on COVID-19 cases across the study area. The result of hotspot analysis reveals that the epicenters of COVID-19 are distributed across Cobb, Fulton, Gwinnett, and DeKalb counties. It was also affirmed that the vaccination records followed the same pattern as COVID-19 cases’ epicenters. The result of the spatial error model performed well and accounted for a considerable percentage of the regression with an adjusted R squared of 0.68, Akaike Information Criterion (AIC) 387.682 and Breusch-Pagan of 9.8091. ESDA was employed to select the main explanatory variables. The selected variables include vaccination, population density, percentage of people that do not have health insurance, black race, Hispanic and these variables accounted for 68% of the number of COVID-19 cases in the state of Georgia during the study period. The study concludes that both COVID-19 cases and vaccinated individuals have spatial peculiarities across counties in Georgia state. Lastly, socio-economic variables and vaccination are very important to reduce the vulnerability of individuals to COVID-19 disease.

Covid-19 vaccination in pregnancy and placental pathology

Objective:To describe and determine the association between Covid-19 vaccination in pregnancy and placental pathology.Methods:Conducted in a tertiary hospital in Medan,Indonesia,from April 30th 2022 to June 30th 2022,this single-center cross-sectional study involved Covid-19 vaccinated and unvaccinated women with singleton full-term pregnancies delivering live fetuses via cesarean section.Maternal characteristics,placental pathologies,and the placental index were documented at enrollment.The association between Covid-19 vaccination status and placental pathology was assessed.Results:The study enrolled 200 pregnant women,including 110 vaccinated women and 90 unvaccinated women.No significant differences were observed in birthweight(P=0.48),placental index(P=0.48),and placental pathology findings[intervillous bleeding(P=0.20),increased syncytial knots(P=0.83),chorangiosis(P=0.13),villous stromal edema(P=0.13),vascular dilation and congestion(P=0.13),and vascular wall thrombus(P=0.71)]between the vaccinated and unvaccinated groups.Conclusions:This study revealed no statistically significant association between Covid-19 vaccination and placental pathology.The findings support the safety of Covid-19 vaccination during pregnancy,in regards to changes of the placental pathology.

A novel immiscible high entropy alloy strengthened via L1_(2)-nanoprecipitate

The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(28)Al_(4)Ti_(3)Co_(3) immiscible high-entropy alloy(HEA)was developed.After vacuum arc melting and copper mold suction casting,this HEA exhibits a unique phase separation microstructure,which consists of striped Cu-rich regions and Fe-rich region.Further magnification of the striped Cu-rich region reveals that it is composed of a Cu-rich dot-like phase and a Fe-rich region.The aging alloy is further strengthened by a L1_(2)-Ni_(3)(AlTi)nanoprecipitates,achieving excellent yield strength(1185 MPa)and uniform ductility(~8.8%).The differential distribution of the L1_(2) nanoprecipitate in the striped Cu-rich region and the external Fe-rich region increased the strength difference between these two regions,which increased the strain gradient and thus improved hetero-deformation induced(HDI)hardening.This work provides a new route to improve the HDI hardening of Fe-Cu alloys.

De Novo Glomerular Diseases after COVID-19 Vaccination: Consequence or Coincidence?

Introduction: Vaccination against COVID-19 has proven highly effective in preventing severe forms of the disease. However, the literature reports several cases associating renal damage and the anti-COVID vaccine. The aim of our work was to report a case series of patients who developed glomerulopathy after anti-COVID-19 vaccine. We evaluated the type of vaccine, the clinico-biological profile, and the anatomopathological, therapeutic and evolutionary aspects. Material and Methods: Prospective descriptive study conducted at the Nephrology Department of CHU IbnSina in Rabat between December 2021 and June 2022 including 9 patients who presented with glomerulopathy after the 1st dose of anti-COVID-19 vaccine. We excluded patients followed for nephropathy. Results: The mean age of our patients was 33 ± 16 years with a sex ratio of 0.8. Six patients received an inactivated vaccine, 2 patients received a mRNA vaccine and 1 patient received a viral vector vaccine. The mean delay between the onset of signs and the date of the first vaccine dose was 3.1 +/? 0.65 months (1 - 6 months). All patients had a nephrotic syndrome, 2 pure and 7 impure: 3 patients had acute renal failure and microscopic hematuria, 2 patients had microscopic hematuria and 2 patients had acute renal failure. Histologically, focal segmental glomerulosclerosis (FSGS) was noted in 4 patients, lupus nephropathy in 3, and membranous nephropathy (MN) in 2. Specific treatment was administered to each patient, depending on the histological type of renal involvement and the context. After 6 months, complete remission was achieved in 5 patients, with no improvement in 2, and one patient was placed on hemodialysis. One patient died of another cause. Conclusion: The causal link between anti-COVID 19 vaccination and renal disease is highly probable, but remains to be confirmed.

Study of Factors Associated with the Practice of Vaccination against COVID-19 among Medical Science Students in Dakar (Senegal)

Introduction: Almost a year after the start of the COVID-19 pandemic, Senegal embarked on a vaccination campaign to protect its population. The objective of this study was to identify the factors influencing the COVID-19 vaccination practices within a health training university in Dakar. Methodology: This was a cross-sectional, descriptive and analytical study carried out from October 21 2021 to February 21 2022 among students at the Elhadj Ibrahima Niass private University in Dakar, Senegal. A 28-question online questionnaire was sent to all students enrolled at the university during this period. Results: Of the 576 students who responded, the average age was 22.60 years, with females predominating (57.81%). Medical students accounted for 66.14% of participants, pharmacy 22.40% and dental surgery 11.46%. Of these, 42.01% were bachelor’s students, 29.51% master’s students and 28.47% doctoral students. Vaccination coverage was 50.35%. Students who considered COVID-19 to be very dangerous were more likely to be vaccinated (OR = 5.05 [2.24-11.9]). Those with poor knowledge of vaccines were less likely to be vaccinated (OR = 0.07 [0.03-0.18]), as were those with poor knowledge of contraindications to vaccination (OR = 0.49 [0.28-0.86]). No association was found between vaccination status and socio-demographic or educational characteristics. Conclusion: In view of the importance of knowledge about COVID-19 vaccination, our results suggest that it is important to involve health students in the Ministry of Health’s awareness-raising strategies, because their support is necessary for better public awareness.

Strengthening mechanism of T8-aged Al-Cu-Li alloy with increased pre-deformation

The microstructure evolution and mechanical properties of a T8-aged Al-Cu-Li alloy with increased pre-deformation(0-15%) were investigated,revealing the microstructure-strength relationship and the intrinsic strengthening mechanism.The results show that increasing the pre-deformation levels remarkably improves the strength of the alloy but deteriorates its ductility.Dislocations introduced by pre-deformation effectively suppress the formation of Guinier-Preston(GP) zones and provide more nucleation sites for T1 precipitates.This leads to more intensive and finer T1 precipitates in the samples with higher pre-deformation levels.Simultaneously,the enhanced precipitation of T1 precipitates and inhibited formation of GP zones cause the decreases in number and sizes of θ′ precipitates.The quantitative descriptions of the strength contributions from different strengthening mechanisms reveal that strengthening contributions from T1 and θ′ precipitates decrease with increasing pre-deformation.The reduced diameters of T1 precipitates are primarily responsible for their weakened strengthening effects.Therefore,the improved strength of the T8-aged Al-Cu-Li alloy is mainly attributed to the stronger strain hardening from the increased pre-deformation levels.

Assessment of the Vaccination Status of Children Aged 6 to 30 Months in a Tertiary Level Health Care Center in Côte d’Ivoire

Introduction: Vaccination coverage in Côte d’Ivoire over the period 2011 to 2015 was below the target of 95% for all antigens. The objective of this study was to analyze the vaccination status of children aged 6 to 30 months with a view to improving vaccination coverage. Patients and Methods: This was a descriptive cross-sectional study which took place from June to September 2018 in a tertiary health center, focusing on children aged 6 to 30 months with a correctly completed health record. The parameters studied were sex, age, educational level of mothers, dates of vaccine administration and reason for missed vaccination opportunities. Results: We retained 212 children. The sex ratio was 1.21 and 93% had received the BCG vaccine before the age of 1 month. The average ages of combined and co-administered vaccines for the 1st and 2nd doses were 7.66 ± 3.81 and 12.88 ± 3.95 weeks, respectively. The median was 16.57 weeks for the 3rd dose. The proportion of vaccinated subjects was greater than 90% for the BCG vaccine and the 3 doses of combined vaccines, and 77% for the yellow fever and measles vaccines. The reasons for non-vaccination were attributable to the children’s parents and health facilities. Conclusion: Improving vaccination coverage requires regular supply of vaccines to centers, and the involvement of all health professionals, community and religious leaders in the vaccination awareness process.

Enhanced mechanical properties of molybdenum alloy originating from composite strengthening of Re and CeO_(2)

To enhance the mechanical properties of molybdenum alloys at both room and high temperatures,Mo-14Re-1CeO_(2)alloy was synthesized using the powder metallurgy method,and the corresponding microstructure and mechanical properties were characterized.The results indicate that the ultimate tensile strength of Mo-14Re-1CeO_(2)reaches 657 MPa,with a total elongation of 35.2%,significantly higher than those of pure molybdenum(453 MPa,and 7.01%).Furthermore,the compression strength of Mo-14Re-1CeO_(2)at high temperature(1200℃)achieves 355 MPa,which is still larger than that of pure molybdenum(221 MPa).It is revealed that there is a coherent interface between CeO_(2)and the Mo-14Re matrix with CeO_(2)particles uniformly distributed in both intergranular and intragranular regions.The improvements in mechanical properties are primarily attributed to the formation of Mo-Re solid solution,grain refinement,and dispersion strengthening effect of CeO_(2).

Humoral Response and Tolerance of Vaccination against SARS-CoV-2 in Adults Senegalese Patients Undergoing Hemodialysis: A Multicenter Prospective Study

Introduction: Following the COVID-19 pandemic, vaccination has been proposed in several countries as the main preventive measure despite very limited data, particularly in dialysis patients. We conducted this study to assess the immunological response to vaccination in Senegalese hemodialysis patients. Patients and Methods: We conducted a prospective study, in two dialysis centers in Dakar from March 30th to August 30th, 2021 including patients on hemodialysis for >6 months, vaccinated against SARS-CoV-2 according to the vaccination schedule recommended by WHO. A vaccine response was considered positive when seroconversion was observed after one dose of vaccine. The clinical efficacy of immunization was defined as the absence of new COVID-19 infection in patients who received a complete vaccination. Results: Among the 81 patients included in the study, 7.4% had anti-Spike IgM antibodies before their first vaccination. Seroprevalence of IgM antibodies was 38.3% one month after the first vaccine dose (at M1) and 8.6% one month after the second dose (at M4). Anti-Spike IgG antibodies were present in 40.3% of patients before vaccination, in 90.1% at M1, and in 59.7% at M4. Among patients previously infected with SARS-CoV-2, 10.2% had IgM antibodies at M0, 31.6% at M1, and 10.5% at M4 post-vaccination. Similarly, seroprevalences of IgG antibodies in this subgroup were 31.5%, 61.3%, and 50.0% respectively at M0, M1, and M4 post-vaccination. A comparison of seroconversion rates between M0 and M4 showed significant differences only for IgG in COVID-19 naive patients. Mean duration in dialysis and the existence of previous COVID-19 infection were associated with patients’ vaccinal response after the two doses. Age, gender and the use of immunosuppressive treatment did not influence post-vaccinal antibody production. Conclusion: Vaccination against COVID-19 in Senegalese hemodialysis patients induced a low seroconversion rate but it was well tolerated. Moreover, the induced protection was neither strong nor durable, particularly in patients with longer duration in dialysis.

Hepatitis B Vaccination Coverage among University Students in Sub-Saharan Africa: Systematic Review and Meta Analysis

Introduction: Hepatitis B is an infectious disease that remains a real public health problem in Africa. Students represent a group at risk for this disease. The objective of this study was to estimate the hepatitis B vaccination coverage rate among students in sub-Saharan Africa. Methods: A systematic search of databases (PubMed, AJOL) and a manual search of Google Scholar was conducted to retrieve all published studies reporting hepatitis B vaccination coverage among students in sub-Saharan Africa. The pooled coverage rate was estimated with a 95% confidence interval (CI) in a random-effects meta-analysis. Results: A total of 35 studies were included and included 20,520 students. The mean age was 22.1 ± 5.1 years with a predominance of female sex (sex ratio F/M = 1.05). The vaccination coverage rate was 28.8% [95% CI: 22.9% - 34.7%]. Disaggregation allowed to estimate coverage rates of 29.8% [95% CI: 22.9% - 36.7%], 23.4% [95% CI: 9.4% - 37.4%] and 17.0% [95% CI: 14.4% - 19.5%] respectively in West Africa, East Africa and Central Africa. Conclusion: Less than a third of students in sub-Saharan Africa are protected against hepatitis B. However, the majority of this target group is at risk of infection. It would be relevant to screen and, if necessary, vaccinate all new students.

Vaccination and Measles Epidemic in the Republic of Congo

Measles is a highly infectious, vaccine-preventable viral disease. Often forgotten, it is potentially fatal. Its main symptoms are: fever, cough, conjunctivitis, rhinitis and skin rash. Serological diagnoses by ELISA test based on the detection of anti-measles virus immunoglobulins M and G (IgM and IgG), are used respectively for the confirmation of suspected cases notified by means of clinical signs of the disease in health structures of the twelve departments of the Republic of Congo involved in the epidemiological surveillance of the disease, and for the evaluation of the immunity conferred by vaccination. During 2021, 459 suspected cases of measles were reported and sampled throughout the country, despite the administration under the Expanded Routine Immunization Program (EPI), of 2 doses of the combined measles-rubella vaccine (RR1 and RR2) in 2020. The notification rate was higher in the south of the country, more precisely in the health structures of the departments of Pointe-Noire (42%) and Brazzaville (11%). During the year 2021, 459 suspected cases of measles were notified and sampled throughout the country with a high notification rate in the south of the country, more precisely in the health structures of the Pointe-Noire departments (42%) and Brazzaville (11%). The samples consisting of human blood (serum) were sent to the National Public Health Laboratory and analyzed by various ELISA tests for the detection of anti-measles immunog-lobulins M and G. The analysis of the results obtained shows that the measles virus circulated in all departments of the country. 154 cases (33.55%) were confirmed positive by IgM ELISA and 98 positive cases (63.63%) were patients vaccinated against measles. Vaccination coverage in RR1 of [50%-95% [(first dose) as well as the lowest RR2 < 50% (second dose) undoubtedly because the COVID-19 pandemic could be the cause of the high frequency of cases positive vaccinated. The non-detection of IgG immunoglobulins in vaccinated patients observed by IgG ELISA tests revealed that 63.26% of vaccinated patients were not immunized against the measles virus. These results confirm those obtained during the Elisa IgM analysis and make it possible to deduce that the quality, the number of doses not properly administered, the individual characteristics of the people as well as the poor conservation of the administered vaccine (non-compliance with the cold chain) would explain the high proportion of positive cases of vaccinated measles observed.

Investigating Non-Compliance with COVID-19 Vaccination through Hesitancy, Refusal, and Access Limitation: A Community-Based Survey from the Democratic Republic of the Congo

Introduction: Vaccination plays a pivotal role in mitigating the repercussions of the COVID-19 pandemic. However, vaccination campaigns encounter obstacles, especially in developing countries like the Democratic Republic of the Congo (DRC). This study aimed at investigating the roles of vaccine hesitancy, refusal, and access barriers, while identifying individual-level factors associated with non-vaccination in Mbujimayi, DRC. Methods: A community-based cross-sectional survey was conducted in three health districts and included 1496 residents. Attitudes and behaviors related to seeking COVID-19 vaccination were assessed using a standardized questionnaire. Hierarchical logistic regression modeling was used to assess factors potentially affecting non-compliance with vaccination. Results: Among participants (median age = 33, IQR = 23.3, M/F sex ratio = 0.7), 60% displayed misconceptions about COVID-19 or its vaccine, while only 35.2% perceived COVID-19 as a significant health threat. Vaccination coverage was estimated at 49.1% (95% CI: 47.5;52.6), with 71.8% of vaccinated individuals having received one dose. Among the unvaccinated individuals, 50.9% expressed no intention to be vaccinated in the future, citing hesitation (30.4%) or refusal (39.6%) mainly due to side effects or distrust of vaccines. Conversely, 32.7% of the unvaccinated persons expressed access barriers despite willingness to be vaccinated. Misconceptions about COVID-19 and its vaccines were the main drivers of vaccination non-compliance. Conclusion: These findings demonstrate significant vaccine non-compliance driven by hesitancy, refusal, and access barriers. Strategies to enhance vaccination coverage and pandemic preparedness should address misconceptions, sociodemographic barriers, and geographic disparities.