RESUMO
BACKGROUND: An effective, affordable, multivalent meningococcal conjugate vaccine is needed to prevent epidemic meningitis in the African meningitis belt. Data on the safety and immunogenicity of NmCV-5, a pentavalent vaccine targeting the A, C, W, Y, and X serogroups, have been limited. METHODS: We conducted a phase 3, noninferiority trial involving healthy 2-to-29-year-olds in Mali and Gambia. Participants were randomly assigned in a 2:1 ratio to receive a single intramuscular dose of NmCV-5 or the quadrivalent vaccine MenACWY-D. Immunogenicity was assessed at day 28. The noninferiority of NmCV-5 to MenACWY-D was assessed on the basis of the difference in the percentage of participants with a seroresponse (defined as prespecified changes in titer; margin, lower limit of the 96% confidence interval [CI] above -10 percentage points) or geometric mean titer (GMT) ratios (margin, lower limit of the 98.98% CI >0.5). Serogroup X responses in the NmCV-5 group were compared with the lowest response among the MenACWY-D serogroups. Safety was also assessed. RESULTS: A total of 1800 participants received NmCV-5 or MenACWY-D. In the NmCV-5 group, the percentage of participants with a seroresponse ranged from 70.5% (95% CI, 67.8 to 73.2) for serogroup A to 98.5% (95% CI, 97.6 to 99.2) for serogroup W; the percentage with a serogroup X response was 97.2% (95% CI, 96.0 to 98.1). The overall difference between the two vaccines in seroresponse for the four shared serogroups ranged from 1.2 percentage points (96% CI, -0.3 to 3.1) for serogroup W to 20.5 percentage points (96% CI, 15.4 to 25.6) for serogroup A. The overall GMT ratios for the four shared serogroups ranged from 1.7 (98.98% CI, 1.5 to 1.9) for serogroup A to 2.8 (98.98% CI, 2.3 to 3.5) for serogroup C. The serogroup X component of the NmCV-5 vaccine generated seroresponses and GMTs that met the prespecified noninferiority criteria. The incidence of systemic adverse events was similar in the two groups (11.1% in the NmCV-5 group and 9.2% in the MenACWY-D group). CONCLUSIONS: For all four serotypes in common with the MenACWY-D vaccine, the NmCV-5 vaccine elicited immune responses that were noninferior to those elicited by the MenACWY-D vaccine. NmCV-5 also elicited immune responses to serogroup X. No safety concerns were evident. (Funded by the U.K. Foreign, Commonwealth, and Development Office and others; ClinicalTrials.gov number, NCT03964012.).
Assuntos
Epidemias , Nível de Saúde , Meningite , Vacinas Meningocócicas , Vacinas Conjugadas , Humanos , Gâmbia/epidemiologia , Mali/epidemiologia , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/efeitos adversos , Vacinas Conjugadas/uso terapêutico , Vacinas Meningocócicas/administração & dosagem , Vacinas Meningocócicas/efeitos adversos , Vacinas Meningocócicas/uso terapêutico , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Adulto , Imunogenicidade da Vacina , Injeções Intramusculares , Meningite/epidemiologia , Meningite/prevenção & controle , Epidemias/prevenção & controleRESUMO
BACKGROUND: Microneedle patches (MNPs) have been ranked as the highest global priority innovation for overcoming immunisation barriers in low-income and middle-income countries. This trial aimed to provide the first data on the tolerability, safety, and immunogenicity of a measles and rubella vaccine (MRV)-MNP in children. METHODS: This single-centre, phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial was conducted in The Gambia. To be eligible, all participants had to be healthy according to prespecified criteria, aged 18-40 years for the adult cohort, 15-18 months for toddlers, or 9-10 months for infants, and to be available for visits throughout the follow-up period. The three age cohorts were randomly assigned in a 2:1 ratio (adults) or 1:1 ratio (toddlers and infants) to receive either an MRV-MNP (Micron Biomedical, Atlanta, GA, USA) and a placebo (0·9% sodium chloride) subcutaneous injection, or a placebo-MNP and an MRV subcutaneous injection (MRV-SC; Serum Institute of India, Pune, India). Unmasked staff ransomly assigned the participants using an online application, and they prepared visually identical preparations of the MRV-MNP or placebo-MNP and MRV-SC or placebo-SC, but were not involved in collecting endpoint data. Staff administering the study interventions, participants, parents, and study staff assessing trial endpoints were masked to treatment allocation. The safety population consists of all vaccinated participants, and analysis was conducted according to route of MRV administration, irrespective of subsequent protocol deviations. The immunogenicity population consisted of all vaccinated participants who had a baseline and day 42 visit result available, and who had no protocol deviations considered to substantially affect the immunogenicity endpoints. Solicited local and systemic adverse events were collected for 14 days following vaccination. Unsolicited adverse events were collected to day 180. Age de-escalation between cohorts was based on the review of the safety data to day 14 by an independent data monitoring committee. Serum neutralising antibodies to measles and rubella were measured at baseline, day 42, and day 180. Analysis was descriptive and included safety events, seroprotection and seroconversion rates, and geometric mean antibody concentrations. The trial was registered with the Pan African Clinical Trials Registry PACTR202008836432905, and is complete. FINDINGS: Recruitment took place between May 18, 2021, and May 27, 2022. 45 adults, 120 toddlers, and 120 infants were randomly allocated and vaccinated. There were no safety concerns in the first 14 days following vaccination in either adults or toddlers, and age de-escalation proceeded accordingly. In infants, 93% (52/56; 95% CI 83·0-97·2) seroconverted to measles and 100% (58/58; 93·8-100) seroconverted to rubella following MRV-MNP administration, while 90% (52/58; 79·2-95·2) and 100% (59/59; 93·9-100) seroconverted to measles and rubella respectively, following MRV-SC. Induration at the MRV-MNP application site was the most frequent local reaction occurring in 46 (77%) of 60 toddlers and 39 (65%) of 60 infants. Related unsolicited adverse events, most commonly discolouration at the application site, were reported in 35 (58%) of 60 toddlers and 57 (95%) of 60 infants that had received the MRV-MNP. All local reactions were mild. There were no related severe or serious adverse events. INTERPRETATION: The safety and immunogenicity data support the accelerated development of the MRV-MNP. FUNDING: Bill & Melinda Gates Foundation.
Assuntos
Vacina contra Sarampo , Vacina contra Rubéola , Rubéola (Sarampo Alemão) , Humanos , Método Duplo-Cego , Gâmbia , Feminino , Masculino , Vacina contra Rubéola/administração & dosagem , Vacina contra Rubéola/imunologia , Vacina contra Rubéola/efeitos adversos , Lactente , Vacina contra Sarampo/administração & dosagem , Vacina contra Sarampo/imunologia , Adulto , Adolescente , Rubéola (Sarampo Alemão)/prevenção & controle , Adulto Jovem , Sarampo/prevenção & controle , Agulhas , Anticorpos Antivirais/sangueRESUMO
BACKGROUND: Novel oral poliovirus vaccine type 2 (nOPV2) has been engineered to improve the genetic stability of Sabin oral poliovirus vaccine (OPV) and reduce the emergence of circulating vaccine-derived polioviruses. This trial aimed to provide key safety and immunogenicity data required for nOPV2 licensure and WHO prequalification. METHODS: This phase 3 trial recruited infants aged 18 to <52 weeks and young children aged 1 to <5 years in The Gambia. Infants randomly assigned to receive one or two doses of one of three lots of nOPV2 or one lot of bivalent OPV (bOPV). Young children were randomised to receive two doses of nOPV2 lot 1 or bOPV. The primary immunogenicity objective was to assess lot-to-lot equivalence of the three nOPV2 lots based on one-dose type 2 poliovirus neutralising antibody seroconversion rates in infants. Equivalence was declared if the 95% CI for the three pairwise rate differences was within the -10% to 10% equivalence margin. Tolerability and safety were assessed based on the rates of solicited adverse events to 7 days, unsolicited adverse events to 28 days, and serious adverse events to 3 months post-dose. Stool poliovirus excretion was examined. The trial was registered as PACTR202010705577776 and is completed. FINDINGS: Between February and October, 2021, 2345 infants and 600 young children were vaccinated. 2272 (96·9%) were eligible for inclusion in the post-dose one per-protocol population. Seroconversion rates ranged from 48·9% to 49·2% across the three lots. The minimum lower bound of the 95% CIs for the pairwise differences in seroconversion rates between lots was -5·8%. The maximum upper bound was 5·4%. Equivalence was therefore shown. Of those seronegative at baseline, 143 (85·6%) of 167 (95% CI 79·4-90·6) infants and 54 (83·1%) of 65 (71·7-91·2) young children seroconverted over the two-dose nOPV2 schedule. The post-two-dose seroprotection rates, including participants who were both seronegative and seropositive at baseline, were 604 (92·9%) of 650 (95% CI 90·7-94·8) in infants and 276 (95·5%) of 289 (92·4-97·6) in young children. No safety concerns were identified. 7 days post-dose one, 78 (41·7%) of 187 (95% CI 34·6-49·1) infants were excreting the type 2 poliovirus. INTERPRETATION: nOPV2 was immunogenic and safe in infants and young children in The Gambia. The data support the licensure and WHO prequalification of nOPV2. FUNDING: Bill & Melinda Gates Foundation.
Assuntos
Poliomielite , Poliovirus , Pré-Escolar , Humanos , Lactente , Anticorpos Antivirais , Formação de Anticorpos , Gâmbia , Esquemas de Imunização , Poliomielite/epidemiologia , Vacina Antipólio OralRESUMO
BACKGROUND: The prevalence of sexually transmitted infections (STIs) in sub-Saharan Africa is poorly described. We aimed to determine the prevalence of five treatable STIs (Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma genitalium, Treponema pallidum) in a sample of Gambian women from the general population. METHODS: Archived specimens from 420 women aged 15 - 69 years living in The Gambia enrolled in a clinical trial of human papilloma virus vaccine schedules were tested in this study. Urine samples were tested for C. trachomatis, N. gonorrhoeae, T. vaginalis and M. genitalium using a commercially available, open-platform multiplex PCR kit. A fragment of the ompA gene was amplified from C. trachomatis-positive samples and sequenced. Serum samples were tested for T. pallidum using the Chembio DPP Syphilis Screen and Confirm test. RESULTS: Overall, 41/420 (9.8%) women tested positive for at least one STI. 32 (7.6%), 9 (2.1%), 1 (0.2%), 1 (0.2%) and 0 (0.0%) tested positive for T. vaginalis, C. trachomatis, N gonorrhoeae, M. genitalium and T. pallidum, respectively. ompA gene sequence was available from five C. trachomatis infections: four were genovar D,one was genovar G and one was genovar F. CONCLUSIONS: STIs are endemic in The Gambia. Monitoring systems should be established.
Assuntos
Infecções por Chlamydia , Gonorreia , Infecções por Mycoplasma , Mycoplasma genitalium , Infecções Sexualmente Transmissíveis , Feminino , Humanos , Infecções por Chlamydia/epidemiologia , Chlamydia trachomatis/genética , Gâmbia/epidemiologia , Gonorreia/epidemiologia , Mycoplasma genitalium/genética , Infecções por Mycoplasma/epidemiologia , Neisseria gonorrhoeae/genética , Prevalência , Rios , Infecções Sexualmente Transmissíveis/epidemiologia , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , IdosoRESUMO
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is evolving differently in Africa than in other regions. Africa has lower SARS-CoV-2 transmission rates and milder clinical manifestations. Detailed SARS-CoV-2 epidemiologic data are needed in Africa. We used publicly available data to calculate SARS-CoV-2 infections per 1,000 persons in The Gambia. We evaluated transmission rates among 1,366 employees of the Medical Research Council Unit The Gambia (MRCG), where systematic surveillance of symptomatic cases and contact tracing were implemented. By September 30, 2020, The Gambia had identified 3,579 SARS-CoV-2 cases, including 115 deaths; 67% of cases were identified in August. Among infections, MRCG staff accounted for 191 cases; all were asymptomatic or mild. The cumulative incidence rate among nonclinical MRCG staff was 124 infections/1,000 persons, which is >80-fold higher than estimates of diagnosed cases among the population. Systematic surveillance and seroepidemiologic surveys are needed to clarify the extent of SARS-CoV-2 transmission in Africa.
Assuntos
COVID-19 , África , Gâmbia/epidemiologia , Humanos , Pandemias , SARS-CoV-2 , Estudos SoroepidemiológicosRESUMO
Human cytomegalovirus (HCMV) infection drives the phenotypic and functional differentiation of NK cells, thereby influencing the responses of these cells after vaccination. NK cell functional differentiation is particularly advanced in African populations with universal exposure to HCMV. To investigate the impact of advanced differentiation on vaccine-induced responses, we studied NK-cell function before and after vaccination with Trivalent Influenza Vaccine (TIV) or diphtheria, tetanus, pertussis, inactivated poliovirus vaccine (DTPiP) in Africans with universal, lifelong HCMV exposure. In contrast to populations with lower prevalence of HCMV infection, no significant enhancement of NK-cell responses (IFN-γ, CD107a, CD25) occurred after in vitro re-stimulation of post-vaccination NK cells with TIV or DTPiP antigens compared to pre-vaccination baseline cells. However, both vaccinations resulted in higher frequencies of NK cells producing IFN-γ in response to exogenous IL-12 with IL-18, which persisted for up to 6 months. Enhanced cytokine responsiveness was restricted to less differentiated NK cells, with increased frequencies of IFN-γ+ cells observed within CD56bright CD57- , CD56dim CD57- NKG2C- and CD56dim CD57- NKG2C+ NK-cell subsets. These data suggest a common mechanism whereby different vaccines enhance NK cell IFN-γ function in HCMV infected donors and raise the potential for further exploitation of NK cell "pre-activation" to improve vaccine effectiveness.
Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Toxoide Diftérico/imunologia , Vacinas contra Influenza/imunologia , Interferon gama/biossíntese , Interleucinas/imunologia , Células Matadoras Naturais/imunologia , Vacinas contra Poliovirus/imunologia , Toxoide Tetânico/imunologia , Adolescente , Adulto , África/epidemiologia , Idoso , Criança , Pré-Escolar , Infecções por Citomegalovirus/etnologia , Infecções por Citomegalovirus/virologia , Toxoide Diftérico/administração & dosagem , Feminino , Humanos , Imunização Secundária , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/farmacologia , Interferon gama/imunologia , Interleucina-12/imunologia , Interleucina-12/farmacologia , Interleucina-18/imunologia , Interleucina-18/farmacologia , Subunidade alfa de Receptor de Interleucina-2/imunologia , Células Matadoras Naturais/efeitos dos fármacos , Proteína 1 de Membrana Associada ao Lisossomo/imunologia , Masculino , Pessoa de Meia-Idade , Vacinas contra Poliovirus/administração & dosagem , Toxoide Tetânico/administração & dosagem , Vacinação , Potência de Vacina , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologia , Adulto JovemRESUMO
The immunogenicity of fractional (one-fifth, 0.1 mL) intradermal doses of the inactivated poliovirus vaccine (ID fIPV) is positively correlated with the size of the intradermal fluid bleb. Training of vaccinators for campaign and routine ID fIPV administration should focus on generating an 8- to 10-mm bleb with each injection. Clinical Trials Registration NCT01847872.
Assuntos
Vesícula/imunologia , Injeções Intradérmicas/estatística & dados numéricos , Vacina Antipólio de Vírus Inativado/administração & dosagem , Vacina Antipólio de Vírus Inativado/imunologia , Anticorpos Antivirais/sangue , Vesícula/epidemiologia , Gâmbia , Humanos , Lactente , Vacina Antipólio de Vírus Inativado/uso terapêutico , Estudos SoroepidemiológicosRESUMO
A clinical trial is any research on human subjects that involves an investigational medicinal product or device. Investigational medicinal products include unlicensed drugs or drugs used outside the product license (e.g. for a new indication) (ICH-GCP). As per the internationally accepted ICH-GCP guidelines, clinical trials should be conducted strictly per the approved protocol. However, during the lifecycle of a trial, protocol deviations may occur. Under ICH efficacy guidelines, protocol deviations are divided into non-important (minor) or important (major), and the latter can jeopardise the participant's rights, safety or the quality of data generated by the study. Existing guidelines on protocol deviation management do not detail or standardise actions to be taken for participants, investigational products, data or samples as part of a holistic management of important protocol deviations. Herein, we propose guidelines to address the current literature gap and promote the standardisation of actions to address important protocol deviations in clinical trials. The advised actions should complement the existing local institutional review board and national regulatory authority requirements.
Assuntos
Ensaios Clínicos como Assunto , Humanos , África Subsaariana , Ensaios Clínicos como Assunto/normas , Guias como Assunto , Projetos de Pesquisa/normasRESUMO
BACKGROUND: Novel oral polio vaccine type 2 (nOPV2) has been used to interrupt circulating vaccine-derived poliovirus type 2 outbreaks following its WHO emergency use listing. This study reports data on the safety and immunogenicity of nOPV2 over two rounds of a campaign in The Gambia. METHODS: This observational cohort study collected baseline symptoms (vomiting, diarrhoea, irritability, reduced feeding, and reduced activity) and axillary temperature from children aged 6 weeks to 59 months in The Gambia before a series of two rounds of a nOPV2 campaign that took place on Nov 20-26, 2021, and March 19-22, 2022. Serum and stool samples were collected from a subset of the participants. The same symptoms were re-assessed during the week following each dose of nOPV2. Stool samples were collected on days 7 and 28, and serum was collected on day 28 following each dose. Adverse events, including adverse events of special interest, were documented for 28 days after each campaign round. Serum neutralising antibodies were measured by microneutralisation assay, and stool poliovirus excretion was measured by real-time RT-PCR. FINDINGS: Of the 5635 children eligible for the study, 5504 (97·7%) received at least one dose of nOPV2. There was no increase in axillary temperature or in any of the baseline symptoms following either rounds of the campaigns. There were no adverse events of special interest and no other safety signals of concern. Poliovirus type 2 seroconversion rates were 70% (95% CI 62 to 78; 87 of 124 children) following one dose of nOPV2 and 91% (85 to 95; 113 of 124 children) following two doses. Poliovirus excretion on day 7 was lower after the second round (162 of 459 samples; 35·3%, 95% CI 31·1 to 39·8) than after the first round (292 of 658 samples; 44·4%, 40·6 to 48·2) of the campaign (difference -9·1%; 95% CI -14·8 to -3·3), showing the induction of mucosal immunity. INTERPRETATION: In a campaign in west Africa, nOPV2 was well tolerated and safe. High rates of seroconversion and evidence of mucosal immunity support the licensure and WHO prequalification of this vaccine. FUNDING: Bill & Melinda Gates Foundation.
Assuntos
Poliomielite , Poliovirus , Humanos , Anticorpos Antivirais , Gâmbia/epidemiologia , Esquemas de Imunização , Imunogenicidade da Vacina , Poliomielite/prevenção & controle , Vacina Antipólio de Vírus Inativado , Vacina Antipólio Oral , Lactente , Pré-EscolarRESUMO
This qualitative study using in-depth interviews and focus group discussions is the first to investigate HPV vaccination in The Gambia; it provides an in-depth analysis of uptake, knowledge, and perceptions of HPV vaccination as well as trust in Ministry of Health vaccination advice. Despite high uptake rates, knowledge of HPV vaccination was low, and the most prominent concern was that the vaccine could cause infertility or is a form of population control. Holistic approaches to addressing HPV vaccine concerns relating to fertility that consider socio-political contexts, including colonial histories, could lead to more positive vaccine perceptions, empowered decisions and to increasing vaccine uptake rates in The Gambia and elsewhere.
Assuntos
Infecções por Papillomavirus , Vacinas contra Papillomavirus , Humanos , Infecções por Papillomavirus/prevenção & controle , Gâmbia , Controle da População , Aceitação pelo Paciente de Cuidados de Saúde , Conhecimentos, Atitudes e Prática em Saúde , Vacinação , Vacinas contra Papillomavirus/efeitos adversos , FertilidadeRESUMO
BACKGROUND: Three pneumococcal conjugate vaccines (PCVs) are currently licensed and WHO prequalified for supply by UN agencies. Here, we aimed to investigate the safety and immunogenicity of SIIPL-PCV compared with PHiD-CV and PCV13, when administered to infants according to a 2 + 1 schedule. METHODS: This single-centre, double-blind, active-controlled, randomised, phase 3 trial was done in Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine clinical trial facilities within two government health centres in the western region of The Gambia. Healthy, PCV-naive infants aged 6-8 weeks were enrolled if they weighed at least 3·5 kg and had no clinically significant health complaints, as determined by history and clinical examination. Eligible infants were randomly assigned (1:1:1) to receive either SIIPL-PCV, PHiD-CV, or PCV13 using permuted blocks of variable size. Parents and the trial staff assessing all study outcomes were masked to vaccine group. The first PCV vaccine was given with other routine Expanded Programme on Immunization vaccines when infants were aged 6-8 weeks (visit 1). At visit 2, routine vaccines alone (without a PCV) were administered. At visit 3, the second dose of the PCV was administered alongside other routine vaccines. At visit 4, a blood sample was collected. Visits 1-4 took place at intervals of 4 weeks. The booster PCV was administered at age 9-18 months (visit 5), with final follow-up 4 weeks after the booster (visit 6). The primary immunogenicity outcome compared the serotype-specific IgG geometric mean concentrations (GMCs) generated by SIIPL-PCV with those generated by PHiD-CV and PCV13, 4 weeks after the booster. We used descriptive 95% CIs without adjustment for multiplicity. Immunogenicity analyses were done in the per protocol population (defined as all children who received all the assigned study vaccines, who had an immunogenicity measurement available, and who had no protocol deviations that might interfere with the immunogenicity assessment). This trial was registered with the Pan African Clinical Trials Registry, PACTR201907754270299, and ClinicalTrials.gov, NCT03896477. FINDINGS: Between July 18 and Nov 14, 2019, 745 infants were assessed for study eligibility. Of these, 85 infants (11%) were ineligible and 660 (89%) were enrolled and randomly assigned to receive SIIPL-PCV (n=220), PHiD-CV (n=220), or PCV13 (n=220). 602 infants (91%) were included in the per protocol immunogenicity population. The median age at vaccination was 46 days (range 42-56). 342 infants (52%) were female and 318 (48%) were male. Post-booster serotype-specific IgG GMCs generated by SIIPL-PCV ranged from 1·54 µg/mL (95% CI 1·38-1·73) for serotype 5 to 12·46 µg/mL (11·07-14·01) for serotype 6B. Post-booster GMCs against shared serotypes generated by PHiD-CV ranged from 0·80 µg/mL (0·72-0·88) for serotype 5 to 17·31 µg/mL (14·83-20·20) for serotype 19F. Post-booster GMCs generated by PCV13 ranged from 2·04 µg/mL (1·86-2·24) for serotype 5 to 15·54 µg/mL (13·71-17·60) for serotype 6B. Post-booster IgG GMCs generated by SIIPL-PCV were higher than those generated by PHiD-CV for seven of the eight shared serotypes (1, 5, 6B, 7F, 9V, 14, and 23F). The GMC generated by serotype 19F was higher after PHiD-CV. The SIIPL-PCV to PHiD-CV GMC ratios for shared serotypes ranged from 0·64 (95% CI 0·52-0·79) for serotype 19F to 2·91 (2·47-3·44) for serotype 1. The serotype 1 GMC generated by SIIPL-PCV was higher than that generated by PCV13, whereas serotype 5, 6A, 19A, and 19F GMCs were higher after PCV13. The SIIPL-PCV to PCV13 GMC ratios ranged from 0·72 (0·60-0·87) for serotype 19A to 1·44 (1·23-1·69) for serotype 1. INTERPRETATION: SIIPL-PCV was safe and immunogenic when given to infants in The Gambia according to a 2 + 1 schedule. This PCV is expected to provide similar protection against invasive and mucosal pneumococcal disease to the protection provided by PCV13 and PHiD-CV, for which effectiveness data are available. Generating post-implementation data on the impact of SIIPL-PCV on pneumococcal disease endpoints remains important. FUNDING: Bill & Melinda Gates Foundation.
Assuntos
Anticorpos Antibacterianos , Infecções Pneumocócicas , Vacinas Pneumocócicas , Criança , Feminino , Humanos , Lactente , Masculino , Gâmbia , Imunogenicidade da Vacina , Imunoglobulina G , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/efeitos adversos , Vacinas Conjugadas/efeitos adversosRESUMO
BACKGROUND: Pneumococcal conjugate vaccines (PCVs) effectively prevent pneumococcal disease, but the global impact of pneumococcal vaccination is hampered by its cost. The evaluation of reduced dose schedules of PCV includes measurement of effects on immunogenicity and carriage acquisition compared to standard schedules. The relevance and feasibility of trials of reduced dose schedules is greatest in middle- and low-income countries, such as The Gambia, where the introduction of PCV resulted in good disease control but where transmission of vaccine-type pneumococci persists. We designed a large cluster-randomised field trial of an alternative reduced dose schedule of PCV compared to the standard schedule, the PVS trial. We will also conduct a sub-study to evaluate the individual-level effect of the two schedules on carriage acquisition, immunogenicity, and co-administration of PCV with yellow fever vaccine, the PVS-AcqImm trial. METHODS: PVS-AcqImm is a prospective, cluster-randomised trial of one dose of PCV scheduled at age 6 weeks with a booster dose at age 9 months (i.e. alternative '1+1' schedule) compared to three primary doses scheduled at 6, 10, and 14 weeks of age (i.e. standard '3+0' schedule). Sub-groups within the alternative schedule group will receive yellow fever vaccine separately or co-administered with PCV at 9 months of age. The primary endpoints are (a) rate of nasopharyngeal vaccine-type pneumococcal acquisition from 9 to 14 months of age, (b) geometric mean concentration of vaccine-type pneumococcal IgG at 18 months of age, and (c) proportions with yellow fever neutralising antibody titre ≥8 four weeks after administration of yellow fever vaccine. Participants and field staff will not be masked to group allocation while the measurement of laboratory endpoints will be masked. Approximately equal numbers of participants will be resident in each of 28 geographic clusters (14 clusters in alternative and standard schedule groups); 784 enrolled for acquisition measurements and 336 for immunogenicity measurements. DISCUSSION: Analysis will account for potential non-independence of measurements by cluster and so interpretation of effects will be at the individual level (i.e. a population of individuals). PVS-AcqImm will evaluate whether acquisition of vaccine-type pneumococci is reduced by the alternative compared to the standard schedule, which is required if the alternative schedule is to be effective. Likewise, evidence of superior immune response at 18 months of age and safety of PCV co-administration with yellow fever vaccine will support decision-making regarding the use of the alternative 1+1 schedule. Acquisition and immunogenicity outcomes will be essential for the interpretation of the results of the large field trial comparing the two schedules. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number 72821613 .
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Vacina contra Febre Amarela , Humanos , Esquemas de Imunização , Lactente , Recém-Nascido , Vacinas Pneumocócicas/efeitos adversos , Estudos Prospectivos , Vacinação , Vacina contra Febre Amarela/efeitos adversosRESUMO
BACKGROUND: A rapid increase in circulating vaccine-derived poliovirus type 2 outbreaks, and the need to reserve inactivated poliovirus vaccine (IPV) for routine immunisation, has increased the value of fractional dose IPV (fIPV) as a measure to prevent acute flaccid paralysis. However, the intradermal route of administration has been viewed as prohibitive to outbreak response campaigns. We aimed to establish the immunogenicity and safety of administering intradermal fIPV with a disposable syringe jet injector (DSJI) or an intradermal adaptor (IDA) compared with standard administration with a BCG needle and syringe (N&S). METHODS: This pragmatic, non-inferiority trial was undertaken in a campaign setting in communities in The Gambia. Children aged 4-59 months without contraindication to vaccination were eligible. Children were not individually randomly assigned; instead, the vaccination teams were randomly assigned (1:1:1) to one of three administration methods. Parents and the field team were not masked, but laboratory personnel were masked. Baseline demographic and anthropometric data were collected from the participants. Public health officers experienced at intradermal immunisation, and nurses without experience, had 2 h of training on each of the administration methods before the campaign. Participants were vaccinated using the administration method in use by the vaccination team in their community. Poliovirus serum neutralising antibodies (SNA) were measured in children aged 24-59 months before and 4 weeks after vaccination. Adverse events and data on injection quality were collected from all participants. The primary outcome was the type 2 immune response rate (seroconversion in seronegative [SNA titre <8] children plus a 4-fold titre rise in seropositive children). Adjusted differences in the immune response between the DSJI or IDA group versus the N&S group were calculated with 97·5% CIs. A margin of -10% was used to define the non-inferiority of DSJI or IDA compared to N&S. Immunogenicity analysis was done per protocol. The trial is registered with ClinicalTrials.govNCT02967783 and has been completed. FINDINGS: Between Oct 28 and Dec 29, 2016, 3189 children aged 4-59 months were recruited, of whom 3170 were eligible. Over 3 days, 2720 children were vaccinated (N&S, 917; IDA, 874; and DSJI, 929). Among 992 children aged 25-59 months with a baseline SNA available, 90·1% (95% CI 86·1-92·9; 281/312) of those vaccinated using the DSJI had an immune response to type 2 compared with 93·8% (90·6-95·8; 331/353) of those vaccinated with N&S and 96·6% (94·0-98·0; 316/327) of those vaccinated with IDA. All (53/53) type 2 seronegative children seroconverted. For polio type 2, non-inferiority was shown for both the IDA (adjusted difference 0·7% [97·5% CI -3·3 to 4·7], unadjusted difference 2·9% [-0·9 to 6·8]) and DSJI (adjusted difference -3·3% [-8·3 to 1·5], unadjusted difference -3·7% [-8·7 to 1·1]) compared with N&S. Non-inferiority was shown for type 1 and 3 for the IDA and DSJI. Neither injection quality nor the training and experience of the vaccinators had an effect on immune response. No safety concerns were reported. INTERPRETATION: In a campaign, intradermal fIPV is safe and generates consistent immune responses that are not dependent on vaccinator experience or injection quality when administered using an N&S, DSJI, or IDA. Countries facing vaccine-derived poliovirus type 2 outbreaks should consider fIPV campaigns to boost population immunity and prevent cases of acute flaccid paralysis. FUNDING: World Health Organization and the Medical Research Council.
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Poliomielite/prevenção & controle , Vacina Antipólio de Vírus Inativado/administração & dosagem , Vacina Antipólio de Vírus Inativado/imunologia , Pré-Escolar , Relação Dose-Resposta a Droga , Estudos de Equivalência como Asunto , Feminino , Gâmbia , Humanos , Lactente , Injeções Intradérmicas , MasculinoRESUMO
BACKGROUND: New strategies to increase measles and rubella vaccine coverage, particularly in low- and middle-income countries, are needed if elimination goals are to be achieved. With this regard, measles and rubella vaccine microneedle patches (MRV-MNP), in which the vaccine is embedded in dissolving microneedles, offer several potential advantages over subcutaneous delivery. These include ease of administration, increased thermostability, an absence of sharps waste, reduced overall costs and pain-free administration. This trial will provide the first clinical trial data on MRV-MNP use and the first clinical vaccine trial of MNP technology in children and infants. METHODS: This is a phase 1/2, randomized, active-controlled, double-blind, double-dummy, age de-escalation trial. Based on the defined eligibility criteria for the trial, including screening laboratory investigations, 45 adults [18-40 years] followed by 120 toddlers [15-18 months] and 120 infants [9-10 months] will be enrolled in series. To allow double-blinding, participants will receive either the MRV-MNP and a placebo (0.9% sodium chloride) subcutaneous (SC) injection or a placebo MNP and the MRV by SC injection (MRV-SC). Local and systemic adverse event data will be collected for 14 days following study product administration. Safety laboratories will be repeated on day 7 and, in the adult cohort alone, on day 14. Unsolicited adverse events including serious adverse events will be collected until the final study visit for each participant on day 180. Measles and rubella serum neutralizing antibodies will be measured at baseline, on day 42 and on day 180. Cohort progression will be dependent on review of the unblinded safety data by an independent data monitoring committee. DISCUSSION: This trial will provide the first clinical data on the use of a MNP to deliver the MRV and the first data on the use of MNPs in a paediatric population. It will guide future product development decisions for what may be a key technology for future measles and rubella elimination. TRIAL REGISTRATION: Pan-African Clinical Trials Registry 202008836432905 . CLINICALTRIALS: gov NCT04394689.
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Vacina contra Sarampo , Sarampo , Vacina contra Rubéola , Rubéola (Sarampo Alemão) , Adolescente , Adulto , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Método Duplo-Cego , Gâmbia , Humanos , Lactente , Sarampo/prevenção & controle , Vacina contra Sarampo/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Rubéola (Sarampo Alemão)/prevenção & controle , Vacina contra Rubéola/efeitos adversos , Adulto JovemRESUMO
Background: In many countries, non-pharmaceutical interventions to limit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission resulted in significant reductions in other respiratory viruses. However, similar data from Africa are limited. We explored the extent to which viruses such as influenza and rhinovirus co-circulated with SARS-CoV-2 in The Gambia during the COVID-19 pandemic. Methods: Between April 2020 and March 2022, respiratory viruses were detected using RT-PCR in nasopharyngeal swabs from 1397 participants with influenza-like illness. An assay to detect SARS-CoV-2 and a viral multiplex RT-PCR assay was used as previously described to detect influenza A and B, respiratory syncytial virus (RSV) A and B, parainfluenza viruses 1-4, human metapneumovirus (HMPV), adenovirus, seasonal coronaviruses (229E, OC43, NL63) and human rhinovirus. Results: Overall virus positivity was 44.2%, with prevalence higher in children <5 years (80%) compared to children aged 5-17 years (53.1%), adults aged 18-50 (39.5%) and >50 years (39.9%), p<0.0001. After SARS-CoV-2 (18.3%), rhinoviruses (10.5%) and influenza viruses (5.5%) were the most prevalent. SARS-CoV-2 positivity was lower in children <5 (4.3%) and 5-17 years (12.7%) than in adults aged 18-50 (19.3%) and >50 years (24.3%), p<0.0001. In contrast, rhinoviruses were most prevalent in children <5 years (28.7%), followed by children aged 5-17 (15.8%), adults aged 18-50 (8.3%) and >50 years (6.3%), p<0.0001. Four SARS-CoV-2 waves occurred, with 36.1%-52.4% SARS-CoV-2 positivity during peak months. Influenza infections were observed in both 2020 and 2021 during the rainy season as expected (peak positivity 16.4%-23.5%). Peaks of rhinovirus were asynchronous to the months when SARS-CoV-2 and influenza peaked. Conclusion: Our data show that many respiratory viruses continued to circulate during the COVID-19 pandemic in The Gambia, including human rhinoviruses, despite the presence of NPIs during the early stages of the pandemic, and influenza peaks during expected months.
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[This corrects the article DOI: 10.1016/j.xcrm.2021.100465.].
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BACKGROUND: Bacterial lipoproteins (BLPs) are expressed across a range of bacteria and are able to activate Toll-like receptor 2 (TLR-2). BLPs enhance immune responses in naive individuals and have therefore been tested as candidate vaccine adjuvants. It is not known whether BLPs affect any preexisting immunity (eg, memory cell response in primed individuals). Colonization with pneumococcus (PNC), which primes for memory cell response, is common in young children. METHODS: We studied effects of BLPs on memory and primary B and CD4+ T cell responses to pneumococcal proteins using adenoidal cells from children. RESULTS: Although BLPs enhanced the primary antibody responses seen in some children with no detectable nasal PNC, BLPs unexpectedly reduced the memory antibody responses in children with positive nasal culture results. Likewise, BLPs augmented the naive but inhibited the memory antigen-driven CD4+ T cell response. The downregulation of the memory responses was associated with increases in interleukin 10 and inducible costimulatory molecule expression, as well as a decrease in CD28 expression in memory CD4+ T cells; all were blocked by anti-TLR2 and anti-B7h antibodies. Augmentation of naive CD4+ T cell proliferation was blocked by anti-B7.2. CONCLUSION: Differential regulation of primary and memory responses by BLPs through TLR2 may have important implications for therapeutic and vaccination strategies against bacterial infection.
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Antígenos de Bactérias/imunologia , Linfócitos B/imunologia , Proteínas de Bactérias/imunologia , Linfócitos T CD4-Positivos/imunologia , Lipoproteínas/imunologia , Streptococcus pneumoniae/imunologia , Receptor 2 Toll-Like/imunologia , Anticorpos Antibacterianos/sangue , Antígenos CD28/biossíntese , Criança , Pré-Escolar , Humanos , Memória Imunológica , Interleucina-10/metabolismoRESUMO
INTRODUCTION: Infertility in Sub-Saharan Africa constitutes an important social and public health problem. Yet, there is a paucity of research on the experiences of men living with infertility, especially in West Africa. This study explored men's aetiological knowledge, views and experiences of infertility in the West Coast region of The Gambia, West Africa. METHODOLOGY: An explorative qualitative study was conducted among men living in the rural and urban communities of the West Coast region of The Gambia using in-depth interviews. Data collection and analysis were performed concurrently, and thematic data analysis was an iterative process carried out using NVivo 11 Analysis Software. RESULTS: Gambian men had generally poor knowledge of infertility, allocating it to God, spiritual powers and bodily (biomedical) factors. While societal norms meant that infertility was generally attributed to women, some men allocated male-factor infertility to poor sperm quality and impotence. Infertility threatened participants' sense of masculinity and resulted in psychosocial distress, including stigma, feelings of isolation, and low self-esteem. CONCLUSION: Normative gendered frameworks of infertility result in high levels of female responsibilisation in the Gambian context. Yet men diagnosed with infertility experience significant, often unrecognized, psychological and social distress. We therefore call for increased attention to male-factor infertility, and the promotion of male engagement with infertility-care and services, both of which are essential for successfully addressing infertility and it's psychosocial consequences in The Gambia.
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Infertilidade Masculina/epidemiologia , Adulto , África Subsaariana/epidemiologia , Análise de Dados , Coleta de Dados , Emoções , Disfunção Erétil , Gâmbia/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde/etnologia , Humanos , Infertilidade Masculina/etiologia , Conhecimento , Masculino , Masculinidade , Pessoa de Meia-Idade , Projetos Piloto , Saúde Pública , População Rural , Estigma SocialRESUMO
The Nairobi Summit, held in November 2019 and convened by the United Nations Fund for Population Activities, claims to have represented "all nations and peoples, and all segments" of society during its high-level conference. The overall aim of the summit was to mobilize political will and financial commitments that are urgently needed to "finally and fully" implement the 1994 International Conference on Population and Development (ICPD) Program of Action. Despite the recommendation by ICPD to incorporate infertility care in reproductive health services, the new Nairobi Statement largely neglects the topic of infertility. This is particularly troublesome as infertility is a global health problem affecting between 52.6 and 72.4 million couples worldwide, with a high prevalence in low- and middle-income settings. For many people around the world, infertility constitutes an emotional, social, and financial burden, yet appropriate services directed toward preventing and addressing infertility are often inaccessible, unaffordable, or nonexistent. With the impetus of a wider reproductive justice community, we call for the integration of infertility into global reproductive health research and practice, urging policy makers, practitioners, researchers, activists, and funders worldwide to bring focused attention to addressing challenges posed by a lack of safe, effective, and dignified fertility management among those in need.