Immunogenicity of rVSVΔG-ZEBOV-GP Ebola vaccination in exposed and potentially exposed persons in the Democratic Republic of the Congo.

Despite more than 300,000 rVSVΔG-ZEBOV-glycoprotein (GP) vaccine doses having been administered during Ebola virus disease (EVD) outbreaks in the Democratic Republic of the Congo (DRC) between 2018 and 2020, seroepidemiologic studies of vaccinated Congolese populations are lacking. This study examines the antibody response at 21 d and 6 mo postvaccination after single-dose rVSVΔG-ZEBOV-GP vaccination among EVD-exposed and potentially exposed populations in the DRC. We conducted a longitudinal cohort study of 608 rVSVΔG-ZEBOV-GP-vaccinated individuals during an EVD outbreak in North Kivu Province, DRC. Participants provided questionnaires and blood samples at three study visits (day 0, visit 1; day 21, visit 2; and month 6, visit 3). Anti-GP immunoglobulin G (IgG) antibody titers were measured in serum by the Filovirus Animal Nonclinical Group anti-Ebola virus GP IgG enzyme-linked immunosorbent assay. Antibody response was defined as an antibody titer that had increased fourfold from visit 1 to visit 2 and was above four times the lower limit of quantification at visit 2; antibody persistence was defined as a similar increase from visit 1 to visit 3. We then examined demographics for associations with follow-up antibody titers using generalized linear mixed models. A majority of the sample, 87.2%, had an antibody response at visit 2, and 95.6% demonstrated antibody persistence at visit 3. Being female and of young age was predictive of a higher antibody titer postvaccination. Antibody response and persistence after Ebola vaccination was robust in this cohort, confirming findings from outside of the DRC.

Poliovirus immunity among adults in the Democratic Republic of the Congo: a cross-sectional serosurvey.

BACKGROUND: Vaccination efforts to eradicate polio currently focus on children under 5 years of age, among whom most cases of poliomyelitis still occur. However, in the Democratic Republic of the Congo (DRC), an outbreak of wild poliovirus type 1 occurred in 2010-2011 in which 16% of cases occurred among adults; in a related outbreak in the neighboring Republic of Congo, 75% of cases occurred among the same adult age-group. Given that infected adults may transmit poliovirus, this study was designed to assess adult immunity against polioviruses. METHODS: We assessed poliovirus seroprevalence using dried blood spots from 5,526 adults aged 15-59 years from the 2013-2014 Demographic and Health Survey in the DRC. RESULTS: Among adults in the DRC, 74%, 72%, and 57% were seropositive for neutralizing antibodies for poliovirus types 1, 2, and 3, respectively. For all three serotypes, seroprevalence tended to be higher among older age groups, those living in households with more children, and among women. CONCLUSIONS: Protection against poliovirus is generally low among adults in the DRC, particularly for type 3 poliovirus. The lack of acquired immunity in adults suggests a potentially limited poliovirus circulation over the lifetime of those surveyed (spanning 1954 through 2014) and transmission of vaccine-derived poliovirus in this age group while underscoring the risk of these outbreaks among adults in the DRC.

Individually Linked Household and Health Facility Vaccination Survey in 12 At-risk Districts in Kinshasa Province, Democratic Republic of Congo: Methods and Metadata.

Health facility (HF) and household (HH) data can complement each other to provide a better understanding of the factors that contribute to vaccination status. In 12 zones with low vaccination coverage within Kinshasa Province, Democratic Republic of Congo, we conducted 2 surveys: (1) a linked HH and HF survey among 6-11-month-old infants, and (2) a HH survey among 12-23-month-old children. Linked survey objectives were to identify factors associated with vaccination status and to explore methodological considerations for linked survey implementation. To provide linked HH and HF data, we enrolled 6-11-month-old infants in HH clusters in each zone and then surveyed HFs located within the 12 zones and cited by caregivers of the enrolled infants as the most recent HF visited for vaccination or curative care. To provide vaccination coverage estimates for the 12-zone area, we enrolled 12-23-month-old children in every fourth HH. Of the HHs with a child aged 6-23 months, 16% were ineligible because they had resided in the neighborhood for <3 months or were unavailable to be interviewed, 4% refused, and 80% were eligible and participated. Of 1224 enrolled infants 6-11 months of age, records of 879 (72%) were linked to one of the 182 surveyed HFs. For the coverage survey, 710 children aged 12-23 months participated. Home-based vaccination cards were available for 1210 of 1934 children (63%) surveyed. The surveys were successful in assessing HH information for 2 age groups, documenting written vaccination history for a large proportion of 6-23-month-old children, linking the majority of infants with their most recently visited HF, and surveying identified HFs. The implementation of the individually linked survey also highlighted the need for a comprehensive list of HFs and an analysis plan that addresses cross-classified clusters with only 1 child.

Poliovirus-Neutralizing Antibody Seroprevalence and Vaccine Habits in a Vaccine-Derived Poliovirus Outbreak Region in the Democratic Republic of Congo in 2018: The Impact on the Global Eradication Initiative.

Despite the successes in wild-type polio eradication, poor vaccine coverage in the DRC has led to the occurrence of circulating vaccine-derived poliovirus outbreaks. This cross-sectional population-based survey provides an update to previous poliovirus-neutralizing antibody seroprevalence studies in the DRC and quantifies risk factors for under-immunization and parental knowledge that guide vaccine decision making. Among the 964 children between 6 and 35 months in our survey, 43.8% (95% CI: 40.6-47.0%), 41.1% (38.0-44.2%), and 38.0% (34.9-41.0%) had protective neutralizing titers to polio types 1, 2, and 3, respectively. We found that 60.7% of parents reported knowing about polio, yet 25.6% reported knowing how it spreads. Our data supported the conclusion that polio outreach efforts were successfully connecting with communities-79.4% of participants had someone come to their home with information about polio, and 88.5% had heard of a polio vaccination campaign. Additionally, the odds of seroreactivity to only serotype 2 were far greater in health zones that had a history of supplementary immunization activities (SIAs) compared to health zones that did not. While SIAs may be reaching under-vaccinated communities as a whole, these results are a continuation of the downward trend of seroprevalence rates in this region.

Strengthening immunization programs through innovative sub-national public-private partnerships in selected provinces in the Democratic Republic of the Congo.

BACKGROUND: Low immunization coverage rates in the Democratic Republic of Congo (DRC) have been reflective of challenges with vaccine access, support and delivery in the country. Motivated by measles and vaccine-derived polio virus (VDPV) outbreaks in 2016-17 and low vaccination rates, the provinces of Haut Lomami and Tanganyika were identified as pilot locations for an innovative approach focused on establishing a consortium of partners supporting local government. This approach was formalized through Memorandums of Understanding (MoUs) between the Bill and Melinda Gates Foundation and Provincial governments in 2018. A third province, Lualaba, established an MoU in 2021. MOU IMPLEMENTATION: These MoUs were 5-year partnerships designed to aid provinces in meeting four key objectives: 80 % immunization coverage, management/elimination of polio/cVDPV outbreaks, improvement of vaccine accessibility, and transfer of immunization service management to provincial leadership. OUTCOMES: During the MoU period, Haut-Lomami saw an increase in full immunization coverage, from 35.7 % (MICS 2018) to 88.9 % (VCS 2021-22), the highest in country. A sharp drop in percentage of zero-dose children was observed in the 3 provinces, confirming improved access to immunization services. Tanganyika saw initial improvement in full immunization coverage, followed by a drop in the VCS 2021-22 due to COVID-19 and healthcare worker strikes. Coverage improved in Tanganyika in the 2023 VCS. The 3 provinces increased their financial contributions to routine immunization and are now the top contributing provinces. While no cVDPV cases were recorded in 2020 and 2021, cVDPV1 and cVDPV2 outbreaks are afflicting the 3 provinces since 2022. CONCLUSIONS: Ultimately, the provincial MoUs were successful in bolstering provincial autonomy and capacity building with the biggest success being a drop in zero-dose children. While not all objectives have been met, the MoU approach served as an innovative program for key aspects of strengthening routine immunization in the DRC.

Acceptability of Vaccination Against COVID-19 Among Healthcare Workers in the Democratic Republic of the Congo.

PURPOSE: This study aims to estimate the acceptability of a future vaccine against COVID-19 and associated factors if offered in Congolese health-care workers (HCWs), since they have the highest direct exposure to the disease. PATIENTS AND METHODS: We conducted an analytical cross-sectional study among 23 Congolese referral hospitals, including three university hospitals, located in three towns from March through 30 April 2020. The main outcome variable was healthcare workers' acceptance of a future vaccine against COVID-19. The associated factors of vaccination willingness were identified through a logistic regression analysis. RESULTS: A sample of 613 HCWs participated in the study and completed the study questionnaire, including 312 (50.9%) men and 301 (49.1%) women. Only 27.7% of HCWs said that they would accept a COVID-19 vaccine if it was available. From the logistic regression analysis, male healthcare workers (ORa=1.17, 95% CI: 1.15-2.60), primarily doctors (ORa=1.59; 95% CI:1.03-2.44) and having a positive attitude towards a COVID-19 vaccine (ORa=11.49; 95% CI: 5.88-22.46) were significantly associated with reporting willingness to be vaccinated. CONCLUSION: For acceptability of vaccination against COVID-19 among others education among HCWs is crucial because health professionals' attitudes about vaccines are an important determinant of their own vaccine uptake and their likelihood of recommending the vaccine to their patients.

Predictors of Non-Adherence to Public Health Instructions During the COVID-19 Pandemic in the Democratic Republic of the Congo.

BACKGROUND: Adherence to public health instructions for the COVID-19 is important for controlling the transmission and the pandemic's health and economic impacts. The aim of this study was to determine the associated factors of non-adherence to public health and social measures instructions. METHODS: This was a cross-sectional study conducted with 1913 participants in two provinces of DRC, Mbuji-Mayi, and Kamina. Predictors of non-adherence to COVID-19 preventive measures were identified using binary logistic regression analysis. P-value<0.05 was considered as a significant predictor. RESULTS: Among 1913 participants (1057 [55.3%] male, age 34.1 [14.9] years), 36.6% were defined as non-adherents. Non-adherence was associated with never studied and primary education level [adjusted odds ratio (aOR)=1.63, CI=1.31-2.03], unemployed status [aOR=1.29, CI=1.01-1.67], living in Kamina (Haut-Lomami province) [aOR=1.63, CI=1.31-2.03], female gender of head of household [aOR=1.53, CI=1.16-2.03], no attending lectures/discussions about COVID-19 [aOR=1.61, CI=1.08-2.40], not being satisfied with the measures taken by the Ministry of Health [aOR=2.26, CI=1.78-2.81], not been regularly informed about the pandemic [aOR=2.25, CI=1.80-2.03], and bad knowledge about COVID-19 [aOR=2.36, CI=1.90-2.93]. CONCLUSION: The rate of non-observance of preventive measures for the COVID-19 pandemic is high, and different factors contributed. The government has to counsel the permanent updating of messages taking into account the context and the progress of the pandemic by using several communication channels.

Occupational COVID-19 Prevention among Congolese Healthcare Workers: Knowledge, Practices, PPE Compliance, and Safety Imperatives.

The SARS-CoV-2 (COVID-19) pandemic has had a tremendous impact on the functionality of health systems and world affairs. We assessed knowledge, attitudes, and practices (KAPs) of healthcare workers (HCWs) in the Democratic Republic of the Congo (DRC). This was a cross-sectional study conducted in 23 referral hospitals located in three towns of the DRC (Lubumbashi, Kamina, Mbuji-Mayi). In total, 613 HCWs were surveyed using the World Health Organization's (WHO's) "Exposure Risk Assessment in the Context of COVID-19" questionnaire. Participants included medical doctors (27.2%) and other categories of HCWs (72.8%). The mean age was 40.3 ± 11.7 years. Over 80% (range: 83-96%) of respondents had sufficient knowledge on each of the three domains: COVID-19 symptoms, disease transmission, and patient care approach. However, attitudes and practices scores were relatively low. Only 27.7% of HCWs were willing to receive a COVID-19 vaccine when it is available, whereas 55% of HCWs complied with good practices; 49.4% wore masks consistently and, surprisingly, only 54.9% used personal protective equipment (PPE) consistently at work and during contact with patients. Knowledge level was positively associated with the use of social media as a primary source of COVID-19-related information and the category of residence, with HCWs from towns already affected by the COVID-19 epidemic being more likely to have positive attitudes (adjusted OR, 1.64; 95%CI, 1.32-2.20) and comply with good practices (aOR, 2.79; 95%CI, 1.93-4.06). This study showed that most Congolese HCWs had sufficient knowledge on COVID-19, whereas the majority did not comply with consistent PPE use. The government of the DRC should urgently take major steps in capacity building for HCWs in outbreak preparedness and supplying hospitals with PPE.

Low Varicella Zoster Virus Seroprevalence Among Young Children in the Democratic Republic of the Congo.

BACKGROUND: Varicella zoster virus (VZV) causes both varicella (chickenpox) and herpes zoster (shingles) and is associated with significant global morbidity. Most epidemiological data on VZV come from high-income countries, and to date there are limited data on the burden of VZV in Africa. METHODS: We assessed the seroprevalence of VZV antibodies among children in the Democratic Republic of Congo in collaboration with the 2013-2014 Demographic and Health Survey. Dried blood spot samples collected from children 6-59 months of age were run on Dynex™ Technologies Multiplier FLEX® chemiluminescent immunoassay platform to assess serologic response. Multivariate logistic regression was then used to determine risk factors for VZV seropositivity. RESULTS: Serologic and survey data were matched for 7,195 children 6-59 months of age, among whom 8% were positive and 2% indeterminate for VZV antibodies in weighted analyses. In multivariate analyses, the odds of seropositivity increased with increasing age, increasing socioeconomic status, mother's education level, rural residence, and province (South Kivu, North Kivu, Bandundu, Bas Congo had the highest odds of a positive test result compared with Kinshasa). CONCLUSION: Our data suggest that VZV is circulating in DRC, and seropositivity is low among children 6-59 months. Seropositivity increased with age and varied by other sociodemographic factors, such as geographic location. This study provides the first nationally representative estimates of VZV infection among children in the DRC.