Long-term cellular immunity of vaccines for Zaire Ebola Virus Diseases

Recent Ebola outbreaks underscore the importance of continuous prevention and disease control efforts. Authorized vaccines include Merck’s Ervebo (rVSV-ZEBOV) and Johnson & Johnson’s two-dose combination (Ad26.ZEBOV/MVA-BN-Filo). Here, in a five-year follow-up of the PREVAC randomized trial (NCT02876328), we report the results of the immunology ancillary study of the trial. The primary endpoint is to evaluate long-term memory T-cell responses induced by three vaccine regimens: Ad26–MVA, rVSV, and rVSV–booster. Polyfunctional EBOV-specific CD4+ T-cell responses increase after Ad26 priming and are further boosted by MVA, whereas minimal responses are observed in the rVSV groups, declining after one year. In-vitro expansion for eight days show sustained EBOV-specific T-cell responses for up to 60 months post-prime vaccination with both Ad26-MVA and rVSV, with no decline. Cytokine production analysis identify shared biomarkers between the Ad26-MVA and rVSV groups. In secondary endpoint, we observed an elevation of pro-inflammatory cytokines at Day 7 in the rVSV group. Finally, we establish a correlation between EBOV-specific T-cell responses and anti-EBOV IgG responses. Our findings can guide booster vaccination recommendations and help identify populations likely to benefit from revaccination

Home care of malaria-infected children of less than 5 years of age in a rural area of the Republic of Guinea

OBJECTIVES: To assess the ability of mothers in a rural area of the Republic of Guinea to identify fever in their children, and to estimate the proportion of children who received antimalarial drugs. METHODS: Children under 5 years of age in 41 villages were selected by a two-step cluster sampling technique. During home visits we examined the children and questioned their mothers about the child?s symptoms and treatment. FINDINGS: Of 784 children examined, 23% were febrile and more than half of them also had a positive smear result for Plasmodium. Mothers reported 63% of children with a temperature > 37.5ºC as sick. Among all children reported as feverish by their mother, 55% had a normal temperature (<37.5ºC). In contrast, a temperature > 37.5ºC was found in 38% of children identified as sick but afebrile by their mother and in 13% of children considered healthy. Among febrile children, 18% were given chloroquine at home or had consulted at the health centre or a dispensary. CONCLUSION: In areas where malaria is endemic, recognition of fever and its presumptive treatment with antimalarial drugs is an essential part of the strategy of the World Health Organization (WHO) to reduce the morbidity due to this disease. This population study shows that mothers often failed to identify fever in their children and to consult or to provide antimalarial treatment. Without great efforts to improve home care, it is unlikely that the morbidity and mortality due to malaria in young children will be greatly reduced

Haematological and Biochemical Reference Values for Healthy Population of Maferinyah Rural Community in Guinea

Guinea’s reference ranges for biological parameters rely on those of Caucasian values. Variability in reference ranges according to the context is well-documented. We conducted this study for the purpose of future malaria clinical trials that assess the efficacy and safety of malaria drugs. A repeated cross-sectional study was carried out, in an apparently healthy cohort population. Surveys took place in Maferinyah rural community, which is located at 75 km from the capital. The 2.5th and 97.5th percentiles were determined nonparametrically and stood for reference intervals. Reference values were determined separately for males and females according to ranges of age (6-10 years of age; 11-15 years of age; 16-45 years of age). Differences between genders were tested using the Mann-Whitney test, while the Friedman test was performed to test differences within each gender group according to the seasons. A total of 450 volunteers were enrolled. The median age was 13. Males 16-45 years of age had significantly higher hematologic and biochemical values compared to a female of the same age (for hematological parameters: Mean Cell Hemoglobin Concentration MCHC p≤0.001, Platelets p≤0.001, monocytes p=0.0305, eosinophils p=0.0225; for biochemical parameters: Aspartate aminotransferase AST p≤0.001, Alanine Aminotransferase ALT p≤0.001, creatinine p≤0.001). We noticed significant seasonal variations for all the biochemical parameters and some hematologic parameters (Mean Corpuscular Hemoglobin MCH, MCHC, Mean Cell volume). This is the first study establishing hematologic and biochemical parameters in Guinea. These findings provide a useful guide for the clinical researchers and care providers. Studies on large scale and in different settings would be also desirable

Perspectives and experiences of healthcare providers on the response to the COVID-19 pandemic in three maternal and neonatal referral hospitals in Guinea in 2020: a qualitative study

Abstract Background The COVID-19 pandemic has adversely affected access to essential healthcare services. This study aimed to explore healthcare providers’ perceptions and experiences of the response to the COVID-19 pandemic in three referral maternal and neonatal hospitals in Guinea. Methods We conducted a longitudinal qualitative study between June and December 2020 in two maternities and one neonatology referral ward in Conakry and Mamou. Participants were purposively recruited to capture diversity of professional cadres, seniority, and gender. Four rounds of in-depth interviews (46 in-depth interviews with 18 respondents) were conducted in each study site, using a semi-structured interview guide that was iteratively adapted. We used both deductive and inductive approaches and an iterative process for content analysis. Results We identified four themes and related sub-themes presented according to whether they were common or specific to the study sites, namely: 1) coping strategies & care reorganization, which include reducing staffing levels, maintaining essential healthcare services, suspension of staff daily meetings, insertion of a new information system for providers, and co-management with COVID-19 treatment center for caesarean section cases among women who tested positive for COVID-19; 2) healthcare providers’ behavior adaptations during the response, including infection prevention and control measures on the wards and how COVID-19-related information influenced providers’ daily work; 3) difficulties encountered by providers, in particular unavailability of personal protective equipment (PPE), lack of financial motivation, and difficulties reducing crowding in the wards; 4) providers perceptions of healthcare service use, for instance their fear during COVID-19 response and perceived increase in severity of complications received and COVID-19 cases among providers and parents of newborns. Conclusion This study provides insights needed to be considered to improve the preparedness and response of healthcare facilities and care providers to future health emergencies in similar contexts

Health-Related Quality of Life of Tuberculosis Patients during the COVID-19 Pandemic in Conakry, Guinea: A Mixed Methods Study

The COVID-19 pandemic has had a significant impact on all facets of life and has exacerbated many challenges faced by people living with tuberculosis (TB). This study aimed to assess the health-related quality of life (HRQoL) of TB patients in Guinea during the first wave of the COVID-19 pandemic. A mixed methods study was conducted using two validated tools to assess HRQoL and qualitative interviews among TB patients enrolled in treatment at 11 health centers in Conakry, Guinea. Logistic regression was used to identify factors associated with the deterioration of HRQoL. We included 439 participants in the study, among whom 44% and 31% experienced pain and anxiety, respectively. We found that an increase in the number of household size and the distance from participants’ residence to the health centers were significantly associated with lower HRQoL. Qualitative interviews highlighted nutritional and financial issues, which were exacerbated during the COVID-19 pandemic and beliefs that the Guinean Government’s assistance plan was insufficient. This study supports the implementation of specific relief plans for TB patients, which includes nutritional and psychological support, especially those whose movements are limited by travel restrictions, preventing access to TB care, reducing work opportunities and exacerbating financial needs and stress