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1.
Int J Infect Dis ; 131: 183-192, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: covidwho-2268084

RESUMEN

OBJECTIVES: We assessed the prevalence of immunoglobulin G (IgG) and IgM against four endemic human coronaviruses and two SARS-CoV-2 antigens among vaccinated and unvaccinated staff at health care centers in Uganda, Sierra Leone, and the Democratic Republic of Congo. METHODS: The government health facility staff who had patient contact in Goma (Democratic Republic of Congo), Kambia District (Sierra Leone), and Masaka District (Uganda) were enrolled. Questionnaires and blood samples were collected at three time points over 4 months. Blood samples were analyzed with the Luminex MAGPIXⓇ. RESULTS: Among unvaccinated participants, the prevalence of IgG/IgM antibodies against SARS-CoV-2 receptor-binding domain or nucleocapsid protein at enrollment was 70% in Goma (138 of 196), 89% in Kambia (112 of 126), and 89% in Masaka (190 of 213). The IgG responses against endemic human coronaviruses at baseline were not associated with SARS-CoV-2 sero-acquisition during follow-up. Among the vaccinated participants, those who had evidence of SARS-CoV-2 IgG/IgM at baseline tended to have higher IgG responses to vaccination than those who were SARS-CoV-2 seronegative at baseline, controlling for the time of sample collection since vaccination. CONCLUSION: The high levels of natural immunity and hybrid immunity should be incorporated into both vaccination policies and prediction models of the impact of subsequent waves of infection in these settings.


Asunto(s)
COVID-19 , Inmunoglobulina G , Humanos , SARS-CoV-2 , Estudios Longitudinales , Prevalencia , Sierra Leona/epidemiología , Uganda/epidemiología , República Democrática del Congo/epidemiología , COVID-19/epidemiología , Inmunoglobulina M , Anticuerpos Antivirales
2.
Int J Public Health ; 67: 1605113, 2022.
Artículo en Inglés | MEDLINE | ID: covidwho-2065662

RESUMEN

Objectives: This cross-sectional survey explored COVID-19 vaccine acceptability among public healthcare facility workers in Kambia (Sierra Leone), Goma (Democratic Republic of Congo) and Masaka (Uganda). Methods: Questionnaire-based interviews conducted between April-October 2021 explored participants' knowledge and perceptions of, and attitudes towards, the COVID-19 pandemic and COVID-19 vaccines, as well as COVID-19 vaccine acceptability (defined as uptake of ≥1 dose or intent to get vaccinated). Results: Whilst most (n = 444; 81.8%) of the 543 participants had one or more concerns about COVID-19 vaccines, 487 (89.7%) nonetheless perceived that they were important for pandemic control. Most participants from Kambia or Masaka either were vaccinated (n = 137/355; 38.6%) or intended to get vaccinated (n = 211/355; 59.4%) against COVID-19. In Goma, all 188 participants were unvaccinated; only 81 (43.1%) participants intended to get vaccinated, and this was associated with positive perceptions about COVID-19 vaccines. In Goma, the most common reasons for not wanting a COVID-19 vaccine were concerns that the vaccines were new (n = 75/107; 70.1%) and fear of side effects (n = 74/107; 69.2%). Conclusion: Reported COVID-19 vaccine acceptability was high among healthcare facility workers in Kambia and Masaka. The lower vaccine acceptability in Goma may highlight the importance of social mobilisation and accurate, accessible information that addresses specific concerns.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19/uso terapéutico , Estudios Transversales , Atención a la Salud , República Democrática del Congo , Humanos , Pandemias , Sierra Leona , Uganda , Vacunación
3.
Lancet Glob Health ; 10(10): e1473-e1484, 2022 10.
Artículo en Inglés | MEDLINE | ID: covidwho-2036657

RESUMEN

BACKGROUND: An estimated 15% of girls aged 9-14 years worldwide have been vaccinated against human papillomavirus (HPV) with the recommended two-dose or three-dose schedules. A one-dose HPV vaccine schedule would be simpler and cheaper to deliver. We report immunogenicity and safety results of different doses of two different HPV vaccines in Tanzanian girls. METHODS: In this open-label, randomised, phase 3, non-inferiority trial, we enrolled healthy schoolgirls aged 9-14 years from Government schools in Mwanza, Tanzania. Eligible participants were randomly assigned to receive one, two, or three doses of either the 2-valent vaccine (Cervarix, GSK Biologicals, Rixensart) or the 9-valent vaccine (Gardasil-9, Sanofi Pasteur MSD, Lyon). The primary outcome was HPV 16 specific or HPV 18 specific seropositivity following one dose compared with two or three doses of the same HPV vaccine 24 months after vaccination. Safety was assessed as solicited adverse events up to 30 days after each dose and unsolicited adverse events up to 24 months after vaccination or to last study visit. The primary outcome was done in the per-protocol population, and safety was analysed in the total vaccinated population. This study was registered in ClinicalTrials.gov, NCT02834637. FINDINGS: Between Feb 23, 2017, and Jan 6, 2018, we screened 1002 girls for eligibility. 72 girls were excluded. 930 girls were enrolled and randomly assigned to receive one dose of Cervarix (155 participants), two doses of Cervarix (155 participants), three doses of Cervarix (155 participants), one dose of Gardasil-9 (155 participants), two doses of Gardasil-9 (155 participants), or three doses of Gardasil-9 (155 participants). 922 participants received all scheduled doses within the defined window (three withdrew, one was lost to follow-up, and one died before completion; two received their 6-month doses early, and one received the wrong valent vaccine in error; all 930 participants were included in the total vaccinated cohort). Retention at 24 months was 918 (99%) of 930 participants. In the according-to-protocol cohort, at 24 months, 99% of participants who received one dose of either HPV vaccine were seropositive for HPV 16 IgG antibodies, compared with 100% of participants who received two doses, and 100% of participants who received three doses. This met the prespecified non-inferiority criteria. Anti-HPV 18 seropositivity at 24 months did not meet non-inferiority criteria for one dose compared to two doses or three doses for either vaccine, although more than 98% of girls in all groups had HPV 18 antibodies. 53 serious adverse events (SAEs) were experienced by 42 (4·5%) of 930 girls, the most common of which was hospital admission for malaria. One girl died of malaria. Number of events was similar between groups and no SAEs were considered related to vaccination. INTERPRETATION: A single dose of the 2-valent or 9-valent HPV vaccine in girls aged 9-14 years induced robust immune responses up to 24 months, suggesting that this reduced dose regimen could be suitable for prevention of HPV infection among girls in the target age group for vaccination. FUNDING: UK Department for International Development/UK Medical Research Council/Wellcome Trust Joint Global Health Trials Scheme, The Bill & Melinda Gates Foundation, and the US National Cancer Institute. TRANSLATION: For the KiSwahili translation of the abstract see Supplementary Materials section.


Asunto(s)
Infecciones por Papillomavirus , Vacunas contra Papillomavirus , Femenino , Vacuna Tetravalente Recombinante contra el Virus del Papiloma Humano Tipos 6, 11 , 16, 18 , Papillomavirus Humano 18 , Humanos , Inmunoglobulina G , Infecciones por Papillomavirus/prevención & control , Vacunas contra Papillomavirus/efectos adversos , Tanzanía
4.
Lancet Glob Health ; 10(10): e1485-e1493, 2022 10.
Artículo en Inglés | MEDLINE | ID: covidwho-2036656

RESUMEN

BACKGROUND: Human papillomavirus (HPV) vaccines are given as a two-dose schedule in children aged 9-14 years, or as three doses in older individuals. We compared antibody responses after one dose of HPV vaccine in the Dose Reduction Immunobridging and Safety Study (DoRIS), a randomised trial of different HPV vaccine schedules in Tanzania, to those from two observational HPV vaccine trials that found high efficacy of one dose up to 11 years against HPV16 and HPV18 (Costa Rica Vaccine Trial [CVT] and Institutional Agency for Research on Cancer [IARC] India trial). METHODS: In this immunobridging analysis of an open-label randomised controlled trial, girls were recruited from 54 government schools in Mwanza, Tanzania, into the DoRIS trial. Girls were eligible if they were aged 9-14 years, healthy, and HIV negative. Participants were randomly assigned (1:1:1:1:1:1), using permutated block sizes of 12, 18, and 24, to one, two, or three doses of the 2-valent vaccine (Cervarix, GSK Biologicals, Rixensart, Belgium) or the 9-valent vaccine (Gardasil 9, Sanofi Pasteur MSD, Lyon, France). For this immunobridging analysis, the primary objective was to compare geometric mean concentrations (GMCs) at 24 months after one dose in the per-protocol population compared with in historical cohorts: the one-dose 2-valent vaccine group in DoRIS was compared with recipients of the 2-valent vaccine Cervarix from CVT and the one-dose 9-valent vaccine group in DoRIS was compared with recipients of the 4-valent vaccine Gardasil (Merck Sharp & Dohme, Whitehouse Station, NJ, USA) from the IARC India trial. Samples were tested together with virus-like particle ELISA for HPV16 and HPV18 IgG antibodies. Non-inferiority of GMC ratios (DoRIS trial vs historical cohort) was predefined as when the lower bound of the 95% CI was greater than 0·50. This study is registered with ClinicalTrials.gov, NCT02834637. FINDINGS: Between Feb 23, 2017, and Jan 6, 2018, we screened 1002 girls for eligibility, of whom 930 were enrolled into DoRIS and 155 each were assigned to one dose, two doses, or three doses of 2-valent vaccine, or one dose, two doses, or three doses of 9-valent vaccine. 154 (99%) participants in the one-dose 2-valent vaccine group (median age 10 years [IQR 9-12]) and 152 (98%) in the one-dose 9-valent vaccine group (median age 10 years [IQR 9-12]) were vaccinated and attended the 24 month visit, and so were included in the analysis. 115 one-dose recipients from the CVT (median age 21 years [19-23]) and 139 one-dose recipients from the IARC India trial (median age 14 years [13-16]) were included in the analysis. At 24 months after vaccination, GMCs for HPV16 IgG antibodies were 22·9 international units (IU) per mL (95% CI 19·9-26·4; n=148) for the DoRIS 2-valent vaccine group versus 17·7 IU/mL (13·9-22·5; n=97) for the CVT (GMC ratio 1·30 [95% CI 1·00-1·68]) and 13·7 IU/mL (11·9-15·8; n=145) for the DoRIS 9-valent vaccine group versus 6·7 IU/mL (5·5-8·2; n=131) for the IARC India trial (GMC ratio 2·05 [1·61-2·61]). GMCs for HPV18 IgG antibodies were 9·9 IU/mL (95% CI 8·5-11·5: n=141) for the DoRIS 2-valent vaccine group versus 8·0 IU/mL (6·4-10·0; n=97) for the CVT trial (GMC ratio 1·23 [95% CI 0·95-1·60]) and 5·7 IU/mL (4·9-6·8; n=136) for the DoRIS 9-valent vaccine group versus 2·2 IU/mL (1·9-2·7; n=129) for the IARC India trial (GMC ratio 2·12 [1·59-2·83]). Non-inferiority of antibody GMCs was met for each vaccine for both HPV16 and HPV18. INTERPRETATION: One dose of HPV vaccine in young girls might provide sufficient protection against persistent HPV infection. A one-dose schedule would reduce costs, simplify vaccine delivery, and expand access to the vaccine. FUNDING: UK Department for International Development/UK Medical Research Council/Wellcome Trust Joint Global Health Trials Scheme, The Bill & Melinda Gates Foundation, and the US National Cancer Institute. TRANSLATION: For the KiSwahili translation of the abstract see Supplementary Materials section.


Asunto(s)
Infecciones por Papillomavirus , Vacunas contra Papillomavirus , Adolescente , Adulto , Anciano , Niño , Reducción Gradual de Medicamentos , Femenino , Vacuna Tetravalente Recombinante contra el Virus del Papiloma Humano Tipos 6, 11 , 16, 18 , Papillomavirus Humano 16 , Humanos , Inmunoglobulina G , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/prevención & control , Tanzanía , Adulto Joven
5.
BMJ Open ; 12(3): e055596, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: covidwho-1736069

RESUMEN

INTRODUCTION: Ebola virus disease (EVD) continues to be a significant public health problem in sub-Saharan Africa, especially in the Democratic Republic of the Congo (DRC). Large-scale vaccination during outbreaks may reduce virus transmission. We established a large population-based clinical trial of a heterologous, two-dose prophylactic vaccine during an outbreak in eastern DRC to determine vaccine effectiveness. METHODS AND ANALYSIS: This open-label, non-randomised, population-based trial enrolled eligible adults and children aged 1 year and above. Participants were offered the two-dose candidate EVD vaccine regimen VAC52150 (Ad26.ZEBOV, Modified Vaccinia Ankara (MVA)-BN-Filo), with the doses being given 56 days apart. After vaccination, serious adverse events (SAEs) were passively recorded until 1 month post dose 2. 1000 safety subset participants were telephoned at 1 month post dose 2 to collect SAEs. 500 pregnancy subset participants were contacted to collect SAEs at D7 and D21 post dose 1 and at D7, 1 month, 3 months and 6 months post dose 2, unless delivery was before these time points. The first 100 infants born to these women were given a clinical examination 3 months post delivery. Due to COVID-19 and temporary suspension of dose 2 vaccinations, at least 50 paediatric and 50 adult participants were enrolled into an immunogenicity subset to examine immune responses following a delayed second dose. Samples collected predose 2 and at 21 days post dose 2 will be tested using the Ebola viruses glycoprotein Filovirus Animal Non-Clinical Group ELISA. For qualitative research, in-depth interviews and focus group discussions were being conducted with participants or parents/care providers of paediatric participants. ETHICS AND DISSEMINATION: Approved by Comité National d'Ethique et de la Santé du Ministère de la santé de RDC, Comité d'Ethique de l'Ecole de Santé Publique de l'Université de Kinshasa, the LSHTM Ethics Committee and the MSF Ethics Review Board. Findings will be presented to stakeholders and conferences. Study data will be made available for open access. TRIAL REGISTRATION NUMBER: NCT04152486.


Asunto(s)
Vacunas contra el Virus del Ébola , Fiebre Hemorrágica Ebola , Adulto , COVID-19 , Niño , Ensayos Clínicos Fase III como Asunto , República Democrática del Congo/epidemiología , Vacunas contra el Virus del Ébola/efectos adversos , Femenino , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Humanos , Esquemas de Inmunización
7.
Pan Afr Med J ; 37(Suppl 1): 28, 2020.
Artículo en Inglés | MEDLINE | ID: covidwho-1033375

RESUMEN

Studies reporting the clinical presentations of COVID-19 in children in sub-Saharan Africa are few, especially from resource-constrained countries. This case series reports the demographic and clinical characteristics and laboratory findings of confirmed cases of COVID-19 in children seen at a district hospital in Sierra Leone. This is a report of nine COVID-19 paediatric cases managed at a secondary level hospital in Kambia District, Northern Sierra Leone. Each child was detected by contact tracing after an infected adult was identified by the COVID-19 response team. The clinical symptoms at presentation, clinical courses, and treatments instituted and patient outcomes are discussed in the context of the facilities available at a typical West African district hospital. Nine out of 30 individuals with confirmed COVID-19 infection who presented to the hospital from 24 April to 20 September 2020 and who were admitted to the isolation center of the hospital were in the paediatric age group. The mean age (SD) and median (IQR) of the children were 69.0 ± 51.7months and 84.0 (10.5, 108.0) months, respectively; five (55.6%) were males. The children were asymptomatic or only had mild illnesses and none required intranasal oxygen or ventilatory support. In the five symptomatic children, the most common symptoms were fever (40%) and cough (40%). All children had normal haemoglobin, platelet and white blood cell (WBC) count. Four children had a positive malaria test and were treated with a complete course of anti-malaria medications. No child received steroid or had specific anti-COVID-19 treatment. All children stayed in the isolation center for 14 days and were re-tested for COVID-19 two weeks after initial diagnosis. No complications have been reported in any of them since discharge. The proportion of children among COVID-19 infected cases seen in a rural community in Sierra Leone was 30%. Fever was the most common symptom and malaria was confirmed in 40% of the infected children. This has significant implication on the diagnosis of COVID-19 in malaria-endemic settings and on how best to manage children who present with fever during the COVID-19 pandemic.


Asunto(s)
COVID-19/diagnóstico , COVID-19/terapia , Niño , Preescolar , Femenino , Hospitales de Distrito , Humanos , Lactante , Masculino , Sierra Leona
8.
Emerg Infect Dis ; 26(11): 2713-2716, 2020 11.
Artículo en Inglés | MEDLINE | ID: covidwho-878004

RESUMEN

Four persons with severe acute respiratory syndrome coronavirus 2 infection had traveled on the same flight from Boston, Massachusetts, USA, to Hong Kong, China. Their virus genetic sequences are identical, unique, and belong to a clade not previously identified in Hong Kong, which strongly suggests that the virus can be transmitted during air travel.


Asunto(s)
Viaje en Avión , Betacoronavirus , Infecciones por Coronavirus/transmisión , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Neumonía Viral/transmisión , Enfermedad Relacionada con los Viajes , Adulto , Anciano , Boston/epidemiología , COVID-19 , Infecciones por Coronavirus/epidemiología , Femenino , Hong Kong/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/epidemiología , SARS-CoV-2
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