Immunological response to fractional-dose yellow fever vaccine administered during an outbreak in Kinshasa, Democratic Republic of the Congo: results 5 years after vaccination from a prospective cohort study.

BACKGROUND: In 2016, outbreaks of yellow fever in Angola and the Democratic Republic of the Congo led to a global vaccine shortage. A fractional dose of 17DD yellow fever vaccine (containing one-fifth [0·1 ml] of the standard dose) was used during a pre-emptive mass campaign in August, 2016, in Kinshasa, Democratic Republic of the Congo among children aged 2 years and older and non-pregnant adults (ie, those aged 18 years and older). 1 year following vaccination, 97% of participants were seropositive; however, the long-term durability of the immune response is unknown. We aimed to conduct a prospective cohort study and invited participants enrolled in the previous evaluation to return 5 years after vaccination to assess durability of the immune response. METHODS: Participants returned to one of six health facilities in Kinshasa in 2021, where study staff collected a brief medical history and blood specimen. We assessed neutralising antibody titres against yellow fever virus using a plaque reduction neutralisation test with a 50% cutoff (PRNT50). Participants with a PRNT50 titre of 10 or higher were considered seropositive. The primary outcome was the proportion of participants seropositive at 5 years. FINDINGS: Among the 764 participants enrolled, 566 (74%) completed the 5-year visit. 5 years after vaccination, 539 (95·2%, 95% CI 93·2-96·7) participants were seropositive, including 361 (94·3%, 91·5-96·2) of 383 who were seronegative and 178 (97·3%, 93·8-98·8) of 183 who were seropositive at baseline. Geometric mean titres (GMTs) differed significantly across age groups for those who were initially seronegative with the lowest GMT among those aged 2-5 years and highest among those aged 13 years and older. INTERPRETATION: A fractional dose of the 17DD yellow fever vaccine induced an immunologic response with detectable titres at 5 years among the majority of participants in the Democratic Republic of the Congo. These findings support the use of fractional-dose vaccination for outbreak prevention with the potential for sustained immunity. FUNDING: Gavi, the Vaccine Alliance through the CDC Foundation. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Serological responses to the MVA-based JYNNEOS monkeypox vaccine in a cohort of participants from the Democratic Republic of Congo.

The current worldwide monkepox outbreak has reaffirmed the continued threat monkeypox virus (MPXV) poses to public health. JYNNEOS, a Modified Vaccinia Ankara (MVA)-based live, non-replicating vaccine, was recently approved for monkeypox prevention for adults at high risk of MPXV infection in the United States. Although the safety and immunogenicity of JYNNEOS have been examined previously, the clinical cohorts studied largely derive from regions where MPXV does not typically circulate. In this study, we assess the quality and longevity of serological responses to two doses of JYNNEOS vaccine in a large cohort of healthcare workers from the Democratic Republic of Congo (DRC). We show that JYNNEOS elicits a strong orthopoxvirus (OPXV)-specific antibody response in participants that peaks around day 42, or 2 weeks after the second vaccine dose. Participants with no prior history of smallpox vaccination or exposure have lower baseline antibody levels, but experience a similar fold-rise in antibody titers by day 42 as those with a prior history of vaccination. Both previously naïve and vaccinated participants generate vaccinia virus and MPXV-neutralizing antibody in response to JYNNEOS vaccination. Finally, even though total OPXV-specific IgG titers and neutralizing antibody titers declined from their peak and returned close to baseline levels by the 2-year mark, most participants remain IgG seropositive at the 2-year timepoint. Taken together, our data demonstrates that JYNNEOS vaccination triggers potent OPXV neutralizing antibody responses in a cohort of healthcare workers in DRC, a monkeypox-endemic region. MPXV vaccination with JYNNEOS may help ameliorate the disease and economic burden associated with monkeypox and combat potential outbreaks in areas with active virus circulation.

Profil de sensibilisation aux allergènes des asthmatiques adultes à Kinshasa, RDC : Etude transversale par prick-tests

Contexte. Environ 80% des asthmatiques sont atopiques. La sensibilisation aux allergènes communs présente certaines variabilités environnementales et géographiques. Objectif. Déterminer le profil de sensibilisation aux allergènes communs des asthmatiques adultes de la ville de Kinshasa. Méthodes. De juin 2017 à février 2018, 216 asthmatiques de 18 ans et plus, des 2 sexes, ont été consécutivement recrutés aux Cliniques Universitaires de Kinshasa et dans certaines paroisses et églises de réveil de la ville de Kinshasa. A l'aide d'un questionnaire validé, les variables sociodémographiques ont été précisées. Le prick-test a été réalisé avec cinq extraits commerciaux standardisés de phanères de chien et chat, l'acarien de poussière de maison (Blomia tropicalis, Bt), les moisissures (Alternaria alternata), et le jaune d'œuf. Résultats. L'âge moyen de la population était de 45,23 (ET=17,56) ans, 74% de sexe féminin, 47 % non sensibilisés et 53% sensibilisés à au moins un allergène. Vingt-cinq pourcent étaient monosensibilisées et 27% plurisensibilisées. Le profil de sensibilisation était Blomia tropicalis (72%), phanères de chat (46%), phanères de chien (34%), Alternaria alternata (13%) et jaune d'œuf (11%). Conclusion. Une plurisensibilisation aux allergènes communs chez les asthmatiques dans notre milieu est présente dont le profil dominé par les acariens et les phanères de chats. Des enquêtes futures incluant un plus grand nombre de sujets et recourant à des batteries de tests plus élargies s'imposent en vue d'une définition d'options diagnostiques et thérapeutiques dans notre contexte

Task shifting in the management of hypertension in Kinshasa, Democratic Republic of Congo: a cross-sectional study.

BACKGROUND: The Democratic Republic of the Congo (DRC) is characterized by a high prevalence of hypertension (HTN) and a high proportion of uncontrolled HTN, which is indicative of poor HTN management. Effective management of HTN in the African region is challenging due to limited resources, particularly human resources for health. To address the shortage of health workers, the World Health Organization (WHO) recommends task shifting for better disease management and treatment. Although task shifting from doctors to nurses is being implemented in the DRC, there are no studies, to the best of our knowledge, that document the association between task shifting and HTN control. The aim of this study was to investigate the association between task shifting and HTN control in Kinshasa, DRC. METHODS: We conducted a cross-sectional study in Kinshasa from December 2015 to January 2016 in five general referral hospitals (GRHs) and nine health centers (HCs). A total of 260 hypertensive patients participated in the study. Sociodemographic, clinical, health care costs and perceived health care quality assessment data were collected using a structured questionnaire. To examine the association between task shifting and HTN control, we assessed differences between GRH and HC patients using bivariate and multivariate analyses. RESULTS: Almost half the patients were female (53.1%), patients' mean age was 59.5 ± 11.4 years. Over three-fourths of patients had uncontrolled HTN. There was no significant difference in the proportion of GRH and HC patients with uncontrolled HTN (76.2% vs 77.7%, p = 0.771). Uncontrolled HTN was associated with co-morbidity (OR = 10.3; 95% CI: 3.8-28.3) and the type of antihypertensive drug used (OR = 4.6; 95% CI: 1.3-16.1). The mean healthcare costs in the GRHs were significantly higher than costs in the HCs (US$ 34.2 ± US$3.34 versus US$ 7.7 ± US$ 0.6, respectively). CONCLUSION: Uncontrolled HTN was not associated with the type of health facility. This finding suggests that the management of HTN at primary healthcare level might be just as effective as at secondary level. However, the high proportion of patients with uncontrolled HTN underscores the need for HTN management guidelines at all healthcare levels.