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1.
Vaccine ; 42(9): 2326-2336, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38448324

RESUMO

This study examined the performance and structures of national immunization program in five middle-income Southeast Asian countries - Malaysia, Thailand, Philippines, Viet Nam, and Myanmar, and analyzed how the different structures relate to the difference in program performance to identify effective strategies in the study countries that facilitated good immunization performance. Data were derived from published literature, and WHO/UNICEF/Gavi databases, with 2010 as the baseline year. UMICs Malaysia and Thailand maintained ≥90 % coverage from 2010 to 2020 and even during the COVID-19 pandemic in 2021. LMICs Viet Nam and donor-supported Myanmar also achieved 80-90 % coverage for most routine vaccines in 2020. The Philippines have not reached ≥90 % coverage since 2010, with the maximum only 72 % (MCV1 and Polio3) in 2020. All study countries prioritize immunization and increased government financing since 2010 by minimum 91 % in Malaysia and 1897 % in Myanmar. However, Myanmar still largely depended on donor support with government financing only 32 % of immunization costs in 2021. The Philippines funds 100 % of immunization costs and ensures sustainable financing for the NIP through earmarked "sin tax" revenues from alcohol and tobacco. Donor support influenced new vaccine introductions among the study countries, with Gavi countries Myanmar and Viet Nam introducing more new vaccines, compared to Gavi-ineligible Malaysia and Thailand. The Philippines reported vaccine stock-outs every year amounting to 28 stock-outs events from 2010 to 2019, compared to only 1-4 stockouts in the other study countries. Donor support, innovative financing, and domestic vaccine manufacturing all play an important role in the efficient delivery of immunization services as demonstrated by the several new vaccine introductions and high immunization rates in Myanmar though Gavi and UNICEF support, additional annual $1.2 billion budget for health and immunization from "sin taxes" in the Philippines, and lack of stockouts for vaccines sourced at affordable prices from domestic manufacturers in Viet Nam.


Assuntos
Programas de Imunização , Cobertura Vacinal , Humanos , Países em Desenvolvimento , Sudeste Asiático
2.
Hum Resour Health ; 21(1): 88, 2023 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-37957695

RESUMO

BACKGROUND: Immunization is regarded as one of the most cost-effective public health interventions in global health. However, its cost-effectiveness depends greatly on the knowledge and skills of vaccinators. With the growing complexity of immunization programs, the need for a well-trained vaccination workforce cannot be overemphasized. In this study, we assessed the knowledge, attitudes, and practices among vaccination staff in Cameroon. METHODS: Through a descriptive cross-sectional design, we used structured questionnaires and observation guides to collect data from vaccination staff in health facilities that were selected by a multistage sampling method. Data were analyzed using STATA 13 software. RESULTS: Overall, we collected data from Expanded Program on Immunization focal staff in 265 health facilities across 68 health districts. Over half (53%) of the surveyed facilities were found in rural areas. Nearly two-thirds of health facilities had immunization focal staff with knowledge gaps for each of the four basic immunization indicators assessed. In other words, only 37% of staff knew how to estimate coverages, 36% knew how to inteprete the EPI monitoring curve, 35% knew how to prepare vaccine orders, and 37% knew how to estimate vaccine wastage. In terms of practices, staff waited for more than ten children to be present before opening a 20-dose vaccine vial in 63% of health facilities, and more than five children to be present before opening a 10-dose vaccine vial in 80% of surveyed facilities. Provision of vaccine-specific information (informing caregiver about vaccine received, explanation of benefits and potential side effects) during immunization sessions was suboptimal for the most part. CONCLUSION: This study suggests marked deficits in immunization knowledge among vaccination staff and exposes common attitudes and practices that could contribute to missed opportunities for vaccination and hinder vaccination coverage and equity in Cameroon. Our findings highlight the urgent need to invest in comprehensive capacity building of vaccination staff in Cameroon, especially now that the immunization program is becoming increasingly complex.


Assuntos
Vacinação , Vacinas , Criança , Humanos , Camarões , Estudos Transversais , Imunização , Programas de Imunização/métodos
3.
BMC Health Serv Res ; 23(1): 1033, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37759205

RESUMO

BACKGROUND: One crucial obstacle to attaining universal immunization coverage in Sub-Saharan Africa is the paucity of timely and high-quality data. This challenge, in part, stems from the fact that many frontline immunization staff in this part of the world are commonly overburdened with multiple data-related responsibilities that often compete with their clinical tasks, which in turn could affect their data collection practices. This study assessed the data management practices of immunization staff and unveiled potential barriers impacting immunization data quality in Cameroon. METHODS: A descriptive cross-sectional study was conducted, involving health districts and health facilities in all 10 regions in Cameroon selected by a multi-stage sampling scheme. Structured questionnaires and observation checklists were used to collect data from Expanded Program of Immunization (EPI) staff, and data were analyzed using STATA VERSION 13.0 (StataCorp LP. 2015. College Station, TX). RESULTS: A total of 265 facilities in 68 health districts were assessed. There was limited availability of some data recording tools like vaccination cards (43%), maintenance registers (8%), and stock cards (57%) in most health facilities. Core data collection tools were incompletely filled in a significant proportion of facilities (37% for registers and 81% for tally sheets). Almost every health facility (89%) did not adhere to the recommendation of filling tally sheets during vaccination; the filling was instead done either before (51% of facilities) or after (25% of facilities) vaccinating several children. Moreso, about 8% of facilities did not collect data on vaccine administration. About a third of facilities did not collect data on stock levels (35%), vaccine storage temperatures (21%), and vaccine wastage (39%). CONCLUSION: Our findings unveil important gaps in data collection practices at the facility level that could adversely affect Cameroon's immunization data quality. It highlights the urgent need for systematic capacity building of frontline immunization staff on data management capacity, standardizing data management processes, and building systems that ensure constant availability of data recording tools at the facility level.


Assuntos
Gerenciamento de Dados , Vacinas , Criança , Humanos , Confiabilidade dos Dados , Camarões/epidemiologia , Estudos Transversais , Vacinação , Imunização , Inquéritos e Questionários , Programas de Imunização
4.
Vaccine ; 41(39): 5769-5774, 2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37573201

RESUMO

INTRODUCTION: Worldwide, tetanus-diphtheria-acellular pertussis (Tdap) vaccination coverage of healthcare professionals (HCPs) is below 40%, but this data is not available for Brazil. We hypothesize that a high number of HCPs are not immune to pertussis in Brazil. Main objective was to determine the seroprevalence of anti-pertussis toxin (anti-PT IgG) among HCPs. Secondary objectives were to evaluate Tdap vaccination coverage, to assess predictive factors associated with anti-PT IgG, and to estimate the decay of anti-PT IgG and time to Tdap vaccination. METHODS: Observational cross-sectional serological study in 352 HCPs who worked at São Paulo Hospital - Federal University of São Paulo (UNIFESP) in 2020, approved by UNIFESP Ethics Committee. Data collected included sociodemographics, knowledge about Tdap, and vaccination status. Anti-PT IgG were quantified by ELISA: <10 IU/mL seronegative and ≥ 10-1000 IU/mL seropositive. Titers ≥ 10-50 IU/mL were classified low positivity, indicating no recent B. pertussis infection or Tdap vaccination; >50 IU/mL high positivity, indicating recent B. pertussis infection or Tdap vaccination, and > 100 IU/mL as acute B. pertussis infection or Tdap vaccination in the previous year. Comparisons were done by Chi-square test, multivariable logistic regression, and Pearsons correlation, at 5% p-level. RESULTS: 331/352 HCPs were not aware the Brazilian National Immunization Program recommends Tdap for all HCPs and pregnant women. 68/339 HCPs received Tdap (mean 3.1 ± 2.0 years). 55/352 were seronegative for pertussis, all unvaccinated. 56/271 with no history of Tdap vaccination had high positivity. The probability of anti-PT IgG > 50 IU/mL was 11.5 times higher in Tdap vaccinated HCPs than in non-vaccinated (p < 0.001). There was a weak but significant correlation between anti-PT IgG and interval of Tdap vaccination (r = 0.404; p = 0.001). Anti-PT IgG dropped 5 IU/mL/year (p = 0.001). CONCLUSION: Better education of HCPs on needs and benefits of Tdap vaccination is critical. Goals must be to improve HCPs vaccination coverage.


Assuntos
Vacinas contra Difteria, Tétano e Coqueluche Acelular , Difteria , Tétano , Coqueluche , Humanos , Feminino , Gravidez , Cobertura Vacinal , Brasil/epidemiologia , Estudos Transversais , Estudos Soroepidemiológicos , Coqueluche/prevenção & controle , Vacinação , Anticorpos Antibacterianos , Difteria/prevenção & controle , Imunoglobulina G , Tétano/prevenção & controle , Atenção à Saúde
5.
Pediatr Infect Dis J ; 42(9): 787-791, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37314214

RESUMO

BACKGROUND: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in dengue-endemic regions has raised concern on the possibility of coinfection, especially in children who bear the highest burden of illness. This study determined the incidence and described the profile of Filipino children with SARS-CoV-2 and dengue coinfection, and compared disease severity and outcome in children with coinfection to a matched group of children with SARS-CoV-2 monoinfection. METHODS: This was a retrospective matched cohort study of pediatric patients 0-18 years old diagnosed with SARS-CoV-2 and dengue coinfection or SARS-CoV-2 monoinfection in the Philippines and reported to the Surveillance and Analysis of Coronavirus disease 2019 (COVID-19) in Children Nationwide registry from March 01, 2020 to June 30, 2022. RESULTS: A total of 3,341 SARS-CoV-2 infections in children were reported. The SARS-CoV-2 and dengue coinfection incidence is 4.34% (n = 145). We matched 120 coinfections to monoinfections according to age, gender and timing of infection. More coinfection cases were classified as mild or moderate COVID-19, whereas more asymptomatic cases were seen in those with monoinfection. Rates were similar for severe and critical COVID-19 in both groups. Coinfections predominantly presented with typical dengue symptoms rather than COVID-19 symptoms and laboratory parameters. No differences in outcomes were observed between coinfection and monoinfection. The case fatality rates are 6.7% for coinfection and 5.0% for monoinfection. CONCLUSIONS: One in every 25 SARS-CoV-2 infections had a dengue coinfection. Continued surveillance is needed to establish the interaction of SARS-CoV-2 and dengue virus, evaluate the impact of COVID-19 and/or dengue vaccination on coinfection and monitor complications of coinfection.


Assuntos
COVID-19 , Coinfecção , Dengue , Humanos , Criança , Recém-Nascido , Lactente , Pré-Escolar , Adolescente , SARS-CoV-2 , COVID-19/complicações , COVID-19/epidemiologia , Coinfecção/epidemiologia , Coinfecção/complicações , Estudos Retrospectivos , Estudos de Coortes , Dengue/complicações , Dengue/epidemiologia , Dengue/diagnóstico
6.
J. pediatr. (Rio J.) ; 99(supl.1): S37-S45, Mar.-Apr. 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1430724

RESUMO

Abstract Objective: To identify and describe learnings from past pandemics and to suggest a framework for vaccine development as part of epi/pandemic readiness. Source of data: Articles/ reviews/letters on pandemic preparedness/ vaccines published between 2005 and 2022 in PubMed, MEDLINE, MedRxiv, BioRxiv, Research Square, Gates Open Research; who. int, cepi.net, visualcapitalist.com, airfinity.com, ted.com websites; press releases. Summary of findings: Disease pandemics caused by emerging pathogens impacted the social development, health and wealth of most societies in human history. In an outbreak, the first months determine its course. To block an exponential spread and the development of an epi/ pandemic early, vaccine availability in sufficient quantities is of paramount importance. It is inevitable that new human viruses will emerge. Any future pandemic will come likely from RNA viruses through zoonotic or vector transmission, but we cannot predict when or where "Disease X" will strike. Public health, scientific and societal readiness plans need to include: continuous identification of new viruses in common mammalian reservoir hosts; continuous epidemiological surveillance, including wastewater sampling; establishment of prototype vaccine libraries against various virus families sharing functional and structural properties; testing of various and innovative vaccine platforms including mRNA, vector, nasal or oral vaccines for suitability by virus family; functional clinical trial sites and laboratory networks in various geographies; more efficient phasing of preclinical and clinical activities; global harmonization and streamlining of regulatory requirements including pre-established protocols; and societal preparedness including combating any pandemic of misinformation. Conclusions: "Outbreaks are unavoidable, pandemics are optional".

7.
Vaccines (Basel) ; 11(3)2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36992229

RESUMO

Background: The third round of the global pulse survey demonstrated that the abrupt and rapid progression of the COVID-19 pandemic significantly disrupted childhood immunization in many countries. Although Cameroon has reported over 120,000 COVID-19 cases, the reported national childhood vaccination coverage during the pandemic seems to have increased compared to that during the pre-COVID-19 period. Indeed, the first dose of the diphtheria, tetanus, and pertussis-containing vaccine (DTP-1) coverage increased from 85.4% in 2019 to 87.7% in 2020, and DTP-3 coverage increased from 79.5% in 2019 to 81.2% in 2020. The paucity of literature on the impact of COVID-19 on childhood vaccination in COVID-19 hotspot regions poses a challenge in developing a context-specific immunization recovery plan, hence the need to conduct this study. Methodology: We conducted a cross-sectional study using 2019 (pre-pandemic period) and 2020 (pandemic period) district childhood immunization data from the DHIS-2 database, weighted using completeness for each data entry against regional data completeness in 2020. Based on COVID-19 incidence, two hotspot regions were selected, with all districts (56/56) included in the final analysis. The Chi-square test was used to compare DTP-1 and DTP-3 coverage during the pre-pandemic and pandemic periods. Results: In the two hotspot regions, 8247 children missed DTP-1, and 12,896 children did not receive DTP-3 vaccines in the pandemic period compared to the results from the pre-pandemic period. Indeed, there was a significant drop in DTP-1 and DTP-3 coverage of 0.8% (p = 0.0002) and 3.1% (p = 0.0003), respectively, in the Littoral Region. Moreover, the Centre Region reported a 5.7% (p < 0.0001) and 7.6% (p < 0.0001) drop in DTP-1 and DTP-3 coverage, respectively. Most districts in the hotspot regions reported a decline in childhood immunization access (62.5%) and utilization (71.4%). Indeed, in the Littoral Region, 46% (11/24) and 58% (14/24) of districts experienced decreased vaccination access and utilization, respectively. Meanwhile, 75% (24/32) and 81% (26/32) of districts in the Centre Region experienced a drop in vaccination access and utilization, respectively. Conclusion: This study reported a situation where the national immunization indicators mask the impact of COVID-19 on childhood immunization in heavily hit regions. Therefore, this study presents valuable information for ensuring continuous vaccination service delivery during public health emergencies. The findings could also contribute to developing an immunization recovery plan and informing policy on future pandemic preparedness and response.

8.
Lancet ; 401(10371): 131-139, 2023 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-36495882

RESUMO

BACKGROUND: Type 2 circulating vaccine-derived polioviruses (cVDPV2) from Sabin oral poliovirus vaccines (OPVs) are the leading cause of poliomyelitis. A novel type 2 OPV (nOPV2) has been developed to be more genetically stable with similar tolerability and immunogenicity to that of Sabin type 2 vaccines to mitigate the risk of cVDPV2. We aimed to assess these aspects of nOPV2 in poliovirus vaccine-naive newborn infants. METHODS: In this randomised, double-blind, controlled, phase 2 trial we enrolled newborn infants at the Matlab Health Research Centre, Chandpur, Bangladesh. We included infants who were healthy and were a single birth after at least 37 weeks' gestation. Infants were randomly assigned (2:1) to receive either two doses of nOPV2 or placebo, administered at age 0-3 days and at 4 weeks. Exclusion criteria included receipt of rotavirus or any other poliovirus vaccine, any infection or illness at the time of enrolment (vomiting, diarrhoea, or intolerance to liquids), diagnosis or suspicion of any immunodeficiency disorder in the infant or a close family member, or any contraindication for venipuncture. The primary safety outcome was safety and tolerability after one and two doses of nOPV2, given 4 weeks apart in poliovirus vaccine-naive newborn infants and the primary immunogenicity outcome was the seroconversion rate for neutralising antibodies against type 2 poliovirus, measured 28 days after the first and second vaccinations with nOPV2. Study staff recorded solicited and unsolicited adverse events after each dose during daily home visits for 7 days. Poliovirus neutralising antibody responses were measured in sera drawn at birth and at age 4 weeks and 8 weeks. This study is registered on ClinicalTrials.gov, NCT04693286. FINDINGS: Between Sept 21, 2020, and Aug 16, 2021, we screened 334 newborn infants, of whom three (<1%) were found to be ineligible and one (<1%) was withdrawn by the parents; the remaining 330 (99%) infants were assigned to receive nOPV2 (n=220 [67%]) or placebo (n=110 [33%]). nOPV2 was well tolerated; 154 (70%) of 220 newborn infants in the nOPV2 group and 78 (71%) of 110 in the placebo group had solicited adverse events, which were all mild or moderate in severity. Severe unsolicited adverse events in 11 (5%) vaccine recipients and five (5%) placebo recipients were considered unrelated to vaccination. 306 (93%) of 330 infants had seroprotective maternal antibodies against type 2 poliovirus at birth, decreasing to 58 (56%) of 104 in the placebo group at 8 weeks. In the nOPV2 group 196 (90%) of 217 infants seroconverted by week 8 after two doses, when 214 (99%) had seroprotective antibodies. INTERPRETATION: nOPV2 was well tolerated and immunogenic in newborn infants, with two doses, at birth and 4 weeks, resulting in almost 99% of infants having protective neutralising antibodies. FUNDING: Bill & Melinda Gates Foundation.


Assuntos
Poliomielite , Poliovirus , Recém-Nascido , Humanos , Lactente , Pré-Escolar , Bangladesh , Anticorpos Antivirais , Vacina Antipólio Oral , Poliomielite/prevenção & controle , Anticorpos Neutralizantes , Método Duplo-Cego
9.
J Pediatr (Rio J) ; 99 Suppl 1: S37-S45, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36495947

RESUMO

OBJECTIVE: To identify and describe learnings from past pandemics and to suggest a framework for vaccine development as part of epi/pandemic readiness. SOURCE OF DATA: Articles/ reviews/letters on pandemic preparedness/ vaccines published between 2005 and 2022 in PubMed, MEDLINE, MedRxiv, BioRxiv, Research Square, Gates Open Research; who.int, cepi.net, visualcapitalist.com, airfinity.com, ted.com websites; press releases. SUMMARY OF FINDINGS: Disease pandemics caused by emerging pathogens impacted the social development, health and wealth of most societies in human history. In an outbreak, the first months determine its course. To block an exponential spread and the development of an epi/ pandemic early, vaccine availability in sufficient quantities is of paramount importance. It is inevitable that new human viruses will emerge. Any future pandemic will come likely from RNA viruses through zoonotic or vector transmission, but we cannot predict when or where "Disease X" will strike. Public health, scientific and societal readiness plans need to include: continuous identification of new viruses in common mammalian reservoir hosts; continuous epidemiological surveillance, including wastewater sampling; establishment of prototype vaccine libraries against various virus families sharing functional and structural properties; testing of various and innovative vaccine platforms including mRNA, vector, nasal or oral vaccines for suitability by virus family; functional clinical trial sites and laboratory networks in various geographies; more efficient phasing of preclinical and clinical activities; global harmonization and streamlining of regulatory requirements including pre-established protocols; and societal preparedness including combating any pandemic of misinformation. CONCLUSIONS: "Outbreaks are unavoidable, pandemics are optional".


Assuntos
Doenças Transmissíveis Emergentes , Vacinas , Animais , Humanos , Doenças Transmissíveis Emergentes/prevenção & controle , Surtos de Doenças/prevenção & controle , Pandemias/prevenção & controle , Mamíferos
10.
Ann N Y Acad Sci ; 1518(1): 209-225, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36183296

RESUMO

The COVID-19 pandemic caught the world largely unprepared, including scientific and policy communities. On April 10-13, 2022, researchers across academia, industry, government, and nonprofit organizations met at the Keystone symposium "Lessons from the Pandemic: Responding to Emerging Zoonotic Viral Diseases" to discuss the successes and challenges of the COVID-19 pandemic and what lessons can be applied moving forward. Speakers focused on experiences not only from the COVID-19 pandemic but also from outbreaks of other pathogens, including the Ebola virus, Lassa virus, and Nipah virus. A general consensus was that investments made during the COVID-19 pandemic in infrastructure, collaborations, laboratory and manufacturing capacity, diagnostics, clinical trial networks, and regulatory enhancements-notably, in low-to-middle income countries-must be maintained and strengthened to enable quick, concerted responses to future threats, especially to zoonotic pathogens.


Assuntos
COVID-19 , Ebolavirus , Humanos , Pandemias , COVID-19/epidemiologia , Surtos de Doenças
11.
Vaccine ; 40(47): 6722-6729, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36055876

RESUMO

INTRODUCTION: Brazil has been at the core of the COVID-19 pandemic, with the second-highest death toll worldwide. A mass vaccination campaign was initiated on May 16th, 2021, in Botucatu, Brazil, where two doses of ChadOx1-nCoV19 were offered 12 weeks apart to all 18-60- year-olds. This context offers a unique opportunity to study the vaccine safety during a mass campaign. METHODS: The first and second doses of the vaccine were administered in May and August 2021, respectively. Emergency room (ER) and hospitalization records were obtained from the Hospital das Clínicas da Faculdade de Medicina de Botucatu for six weeks before and six weeks after the first and second doses, from 4 April to 19 September 2021. Diagnoses with COVID-19-related ICD codes were excluded to distinguish any trends resulting from the COVID-19 pandemic. ER and hospital visits during the two time periods were compared, including an ICD code comparison, to identify any changes in disease distributions. Data were scanned for a defined list of Adverse Events of Special Interest (AESIs), as presented by the Safety Platform for Emergency Vaccines. RESULTS AND DISCUSSION: A total of 77,683 and 74,051 subjects received dose 1 and dose 2 of ChadOx1-nCoV19, respectively. Vaccination was well tolerated and not associated with any major safety concerns. Increases in ER visits 1 week following both doses were primarily seen in ICD codes related to non-serious side effects of the vaccine, including vaccination site pain and other local events. The neurological AESIs identified (2 of 3 cases of multiple sclerosis) were relapses of a pre-existing condition. One potentially serious hospitalization event for Bell's palsy had onset before vaccination with dose 1, in a patient who also had a viral infection of the central nervous system. There was no myocarditis, pericarditis cases, or vaccine-related increases in thromboembolic events.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , Brasil/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Programas de Imunização , Pandemias/prevenção & controle , Vacinação/efeitos adversos , Vacinas/efeitos adversos
12.
Lancet Infect Dis ; 22(7): 990-1001, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35447085

RESUMO

BACKGROUND: We previously reported the efficacy of the adjuvanted-protein COVID-19 vaccine candidate S-Trimer (SCB-2019) in adults who showed no evidence of previous exposure to SARS-CoV-2. In this study, we aimed to investigate the extent of protection afforded by previous exposure to SARS-CoV-2 on subsequent COVID-19 infection, as well as the efficacy, safety, and reactogenicity of SCB-2019 in participants who were enrolled in the Study evaluating Protective-Efficacy and safety of Clover's Trimeric Recombinant protein-based and Adjuvanted COVID-19 vaccine (SPECTRA) trial who had already been exposed to SARS-CoV-2 before vaccination. METHODS: In a phase 2 and 3 multicentre, double-blind, randomised, placebo-controlled trial (SPECTRA) done at 31 sites in five countries, participants were randomly assigned 1:1 using the Cenduit Interactive Response Technology system (IQVIA, Durham, NC, USA), with a block size of six, to receive two doses of either SCB-2019 or placebo 21 days apart. The primary outcomes of the SPECTRA trial were vaccine efficacy, measured by real-time PCR (rtPCR)-confirmed COVID-19 of any severity, with onset from 14 days after the second vaccine dose, as well as the safety and solicited local and systemic adverse events in the phase 2 subset. Here, we present secondary analyses to calculate the protective efficacy due to previous exposure to SARS-CoV-2 against reinfection with COVID-19 according to severity in SPECTRA participants who had evidence of exposure to SARS-CoV-2 at baseline, including efficacy against identified viral variants, as well as efficacy of SCB-2019 vaccination in this population. FINDINGS: We enrolled 30 174 participants between March 24, 2021, and Aug 10, 2021. In the 14 670 participants who were randomly assigned to receive placebo, there were 418 (2·8%) confirmed cases of COVID-19; 65 (0·9%) of 7339 SARS-CoV-2-exposed participants, and 353 (4·8%) of 7331 SARS-CoV-2-naive participants (attack rates of 5·5 cases per 100 person-years for SARS-CoV-2-exposed participants and 32·4 cases per 100 person-years for SARS-CoV-2-naive participants). Protective efficacy due to previous exposure to SARS-CoV-2 was 83·2% (95% CI 78·0-87·3) against any COVID-19, 92·5% (82·9-97·3) against moderate-to-severe COVID-19, and 100% (59·3-100) against severe COVID-19; no SARS-CoV-2-exposed participants had hospitalisation associated with COVID-19. Protective efficacy against variants were 100% for alpha (B.1.1.7) and lambda (C.37) variants, 88·6% (14·9-99·7) for B.1.623, 93·6% (80·1-98·7) for gamma (P.1), and 92·4% (81·2-97·6) for mu (B.1.621) variants, and lowest against beta (B.1.351; 72·2% [33·1-89·9]) and delta (B.1.617.2; 77·2% [61·3-87·2]) variants. In addition, one dose of SCB-2019 had 49·9% (1·5-75·6) efficacy against any symptomatic COVID-19, and two doses had 64·2% (26·5-83·8) efficacy. SCB-2019 was well tolerated in SARS-CoV-2-exposed participants, but was associated with higher rates of injection site pain (89 [33·8%] of 263 participants) than placebo (16 [6·7%] of 239 participants). Rates of solicited systemic adverse events, severe adverse events, and serious adverse events were similar between vaccine and placebo groups, and with rates in SARS-CoV-2-naive vaccine recipients. INTERPRETATION: Previous exposure to SARS-CoV-2 decreased the risk and severity of subsequent COVID-19 infection, even against newly emerging variants. Protection is further enhanced by one or two doses of SCB-2019. FUNDING: Clover Biopharmaceuticals, The Coalition for Epidemic Preparedness Innovations (CEPI).


Assuntos
COVID-19 , SARS-CoV-2 , Adulto , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Método Duplo-Cego , Humanos , Imunogenicidade da Vacina , Reinfecção , Vacinação , Vacinas de Subunidades
13.
Lancet ; 399(10323): 461-472, 2022 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-35065705

RESUMO

BACKGROUND: A range of safe and effective vaccines against SARS CoV 2 are needed to address the COVID 19 pandemic. We aimed to assess the safety and efficacy of the COVID-19 vaccine SCB-2019. METHODS: This ongoing phase 2 and 3 double-blind, placebo-controlled trial was done in adults aged 18 years and older who were in good health or with a stable chronic health condition, at 31 sites in five countries (Belgium, Brazil, Colombia, Philippines, and South Africa). The participants were randomly assigned 1:1 using a centralised internet randomisation system to receive two 0·5 mL intramuscular doses of SCB-2019 (30 µg, adjuvanted with 1·50 mg CpG-1018 and 0·75 mg alum) or placebo (0·9% sodium chloride for injection supplied in 10 mL ampoules) 21 days apart. All study staff and participants were masked, but vaccine administrators were not. Primary endpoints were vaccine efficacy, measured by RT-PCR-confirmed COVID-19 of any severity with onset from 14 days after the second dose in baseline SARS-CoV-2 seronegative participants (the per-protocol population), and the safety and solicited local and systemic adverse events in the phase 2 subset. This study is registered on EudraCT (2020-004272-17) and ClinicalTrials.gov (NCT04672395). FINDINGS: 30 174 participants were enrolled from March 24, 2021, until the cutoff date of Aug 10, 2021, of whom 30 128 received their first assigned vaccine (n=15 064) or a placebo injection (n=15 064). The per-protocol population consisted of 12 355 baseline SARS-CoV-2-naive participants (6251 vaccinees and 6104 placebo recipients). Most exclusions (13 389 [44·4%]) were because of seropositivity at baseline. There were 207 confirmed per-protocol cases of COVID-19 at 14 days after the second dose, 52 vaccinees versus 155 placebo recipients, and an overall vaccine efficacy against any severity COVID-19 of 67·2% (95·72% CI 54·3-76·8), 83·7% (97·86% CI 55·9-95·4) against moderate-to-severe COVID-19, and 100% (97·86% CI 25·3-100·0) against severe COVID-19. All COVID-19 cases were due to virus variants; vaccine efficacy against any severity COVID-19 due to the three predominant variants was 78·7% (95% CI 57·3-90·4) for delta, 91·8% (44·9-99·8) for gamma, and 58·6% (13·3-81·5) for mu. No safety issues emerged in the follow-up period for the efficacy analysis (median of 82 days [IQR 63-103]). The vaccine elicited higher rates of mainly mild-to-moderate injection site pain than the placebo after the first (35·7% [287 of 803] vs 10·3% [81 of 786]) and second (26·9% [189 of 702] vs 7·4% [52 of 699]) doses, but the rates of other solicited local and systemic adverse events were similar between the groups. INTERPRETATION: Two doses of SCB-2019 vaccine plus CpG and alum provides notable protection against the entire severity spectrum of COVID-19 caused by circulating SAR-CoV-2 viruses, including the predominating delta variant. FUNDING: Clover Biopharmaceuticals and the Coalition for Epidemic Preparedness Innovations.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Vacinas contra COVID-19/uso terapêutico , COVID-19/prevenção & controle , Glicoproteína da Espícula de Coronavírus/uso terapêutico , Adolescente , Adulto , Idoso , Compostos de Alúmen/uso terapêutico , Bélgica , Brasil , Colômbia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oligodesoxirribonucleotídeos/uso terapêutico , Filipinas , Multimerização Proteica , Proteínas Recombinantes/uso terapêutico , Risco , SARS-CoV-2 , África do Sul , Eficácia de Vacinas , Adulto Jovem
14.
Nat Commun ; 12(1): 5861, 2021 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-34615860

RESUMO

Several COVID-19 vaccines have shown good efficacy in clinical trials, but there remains uncertainty about the efficacy of vaccines against different variants. Here, we investigate the efficacy of ChAdOx1 nCoV-19 (AZD1222) against symptomatic COVID-19 in a post-hoc exploratory analysis of a Phase 3 randomised trial in Brazil (trial registration ISRCTN89951424). Nose and throat swabs were tested by PCR in symptomatic participants. Sequencing and genotyping of swabs were performed to determine the lineages of SARS-CoV-2 circulating during the study. Protection against any symptomatic COVID-19 caused by the Zeta (P.2) variant was assessed in 153 cases with vaccine efficacy (VE) of 69% (95% CI 55, 78). 49 cases of B.1.1.28 occurred and VE was 73% (46, 86). The Gamma (P.1) variant arose later in the trial and fewer cases (N = 18) were available for analysis. VE was 64% (-2, 87). ChAdOx1 nCoV-19 provided 95% protection (95% CI 61%, 99%) against hospitalisation due to COVID-19. In summary, we report that ChAdOx1 nCoV-19 protects against emerging variants in Brazil despite the presence of the spike protein mutation E484K.


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/imunologia , COVID-19/virologia , Filogenia , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Brasil , ChAdOx1 nCoV-19 , Estudos de Coortes , Relação Dose-Resposta Imunológica , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Vacinação , Carga Viral/imunologia , Adulto Jovem
15.
Pan Afr Med J ; 39: 91, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34466193

RESUMO

INTRODUCTION: Mozambique is one of the poorest nations in the world and its health budget is heavily dependent on external funding. Increasingly, donors prefer to direct their funds through international non-governmental organizations instead of direct donations to the State budget. In the current climate of increased emphasis on health system strengthening, a strong and stable partnership between government and international non-governmental organizations is pivotal for health system strengthening in Mozambique. METHODS: the study evaluates the current partnership through a standardized survey to healthcare workers employed by international non-governmental organizations in health (INGO, private) and the ministry of health (MOH, public). Results of the survey have been analyzed only descriptively and no statistical evaluations have been performed. RESULTS: out of the valid 109 responses obtained 55.1% were from MOH cadres and 45.0% from INGO cadres. Most have been in the health sector for more than 5 years. Most of the respondents recognize that INGOs assist the government in strengthening the health system (71.6%), see the internal brain drain to INGOs and salary scale difference as major problems (70.6% and 78.0%); 87.2% reported that the coordination between INGOs and government needs to be improved. MOH cadres perceived the migration of cadres to INGOs and the need for improving coordination as major issues more acutely than their INGO counterparts (80.0% vs. 59.2% and 88.3% vs. 85.7% respectively). INGOs were perceived to offer better quality health services by 51.4% of respondents (of these 69.4% were INGO respondents). The quality of health services was alike between INGOs and MOH for 33% of the respondents. CONCLUSION: through the various efforts outlined the MOH and INGOs are moving towards an environment of mutual accountability, joint planning and coordination as well as harmonization of activities; but there are still challenges to be addressed. Prioritization and increased funding of the planning unit and planning and cooperation directorate as well as strategies for workforce retention are urgently needed.


Assuntos
Atenção à Saúde/organização & administração , Pessoal de Saúde/organização & administração , Organizações/organização & administração , Parcerias Público-Privadas/organização & administração , Estudos Transversais , Humanos , Agências Internacionais , Moçambique , Setor Privado , Setor Público , Qualidade da Assistência à Saúde , Inquéritos e Questionários
16.
BMC Infect Dis ; 21(1): 144, 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33541281

RESUMO

BACKGROUND: The respiratory syncytial virus (RSV) has been established as a leading cause of acute lower respiratory illness (ALRI) in infants and children. In 2015, the global disease burden (GBD) study estimated that the overall RSV-ALRI mortality could be as high as 118,200, with most death occurring in low- and middle-incomes countries (LMIC). This study aimed to assess the burden of RSV infection among children less than 2 years with acute respiratory infections (ARI) in the Littoral region of Cameroon. METHODS: We carried out a cross-sectional study in seven health centres in the Littoral region of Cameroon. Venous blood was collected using serum separation tubes from eligible children who visited these health centres with acute respiratory infections. ELISA (Enzyme-linked immunosorbent assay) testing was used to assess the seroprevalence of anti-IgM RSV for the total population and by selected demographic and health parameters and potential risk factors. RESULTS: The overall RSV-associated ARI seroprevalence was 33% (95%CI:23.6-42.3; 33/100 children). The only demographic factor significantly associated with RSV acquisition was age of 6 months and below (odds ratio: 7.54 (2.62, 23.36); p = 0.000). Children who were clinically diagnosed to be concomitantly infected with malaria had a lower risk of RSV infection (odds ratio: 0.38 (0.14, 0.95; P = 0.03). CONCLUSIONS: The RSV burden is high among children less than 2 years with ARI in the Littoral region of Cameroon. There is a need for an effective public health RSV surveillance system with standard laboratory techniques and equipment to better understand the RSV disease age-specific incidence, seasonality, risk factors and RSV burden among patients in communities in Cameroon.


Assuntos
Infecções por Vírus Respiratório Sincicial/complicações , Vírus Sincicial Respiratório Humano , Infecções Respiratórias/etiologia , Infecções Respiratórias/virologia , Camarões/epidemiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Incidência , Lactente , Masculino , Fatores de Risco , População Rural , Estudos Soroepidemiológicos
17.
bioRxiv ; 2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-34981049

RESUMO

On the 24 th November 2021 the sequence of a new SARS CoV-2 viral isolate spreading rapidly in Southern Africa was announced, containing far more mutations in Spike (S) than previously reported variants. Neutralization titres of Omicron by sera from vaccinees and convalescent subjects infected with early pandemic as well as Alpha, Beta, Gamma, Delta are substantially reduced or fail to neutralize. Titres against Omicron are boosted by third vaccine doses and are high in cases both vaccinated and infected by Delta. Mutations in Omicron knock out or substantially reduce neutralization by most of a large panel of potent monoclonal antibodies and antibodies under commercial development. Omicron S has structural changes from earlier viruses, combining mutations conferring tight binding to ACE2 to unleash evolution driven by immune escape, leading to a large number of mutations in the ACE2 binding site which rebalance receptor affinity to that of early pandemic viruses.

18.
Lancet ; 397(10269): 99-111, 2021 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-33306989

RESUMO

BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca.


Assuntos
Vacinas contra COVID-19 , COVID-19/prevenção & controle , Adolescente , Adulto , Idoso , Brasil , Vacinas contra COVID-19/efeitos adversos , ChAdOx1 nCoV-19 , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , África do Sul , Resultado do Tratamento , Reino Unido , Adulto Jovem
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