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1.
Aust J Gen Pract ; 49(10): 625-629, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33015676

RESUMO

BACKGROUND: The availability of a COVID-19 vaccine is being heralded as the solution to control the current COVID-19 pandemic, reduce the number of infections and deaths and facilitate resumption of our previous way of life. OBJECTIVE: The aim of this article is to provide a framework for primary care of what will be needed to optimise COVID-19 vaccine confidence and uptake in Australia once the vaccine prioritisation schedule and key target groups are known. DISCUSSION: While a number of vaccines are currently under development, with at least seven undergoing phase III trials (28 August 2020), it is hoped that an effective COVID-19 vaccine will become available to the public in 2021. Ensuring public confidence in vaccine safety and effectiveness will be crucial to facilitate uptake. General practitioners are at the forefront of public health, and one of the most trusted sources for patients. In this article, the authors discuss the expedited vaccine development process for COVID-19 vaccines; the likely vaccine prioritisation schedule and anticipated key target groups; the behavioural and social drivers of vaccination acceptance, including the work required to facilitate this; and the implications for general practice.


Assuntos
Infecções por Coronavirus , Clínicos Gerais/psicologia , Programas de Imunização/organização & administração , Pandemias , Pneumonia Viral , Saúde Pública/métodos , Vacinação , Vacinas Virais/farmacologia , Austrália , Betacoronavirus , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Grupos Focais , Acesso aos Serviços de Saúde/organização & administração , Humanos , Pandemias/prevenção & controle , Aceitação pelo Paciente de Cuidados de Saúde , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Atenção Primária à Saúde/métodos , Autoimagem , Vacinação/métodos , Vacinação/psicologia
2.
BMC Infect Dis ; 20(1): 641, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32867698

RESUMO

BACKGROUND: Maternal poliovirus antibodies could provide passive immunity to the newborns from poliovirus infection during their first few months of life, but they may impair the immune responses of infants to the poliovirus vaccine as well. In our study, we pooled the data from three clinical trials of the inactivated poliovirus vaccine (IPV) based on Sabin strains to investigate the effect of maternal poliovirus antibodies on the immune responses of infants to poliovirus vaccines. METHODS: There were five groups in the pooled analysis, including low-dose Sabin IPV, medium-dose Sabin IPV, high-dose Sabin IPV, control Sabin IPV, and control Salk IPV groups. We reclassified the infants in different groups according to their maternal poliovirus antibodies by two methods, the first one included maternal antibody negative (< 1:8) and maternal antibody positive (≥1:8), and the second one included maternal antibody titer < 1:8, 1:8 ~ < 1:32 and ≥ 1:32. Then, we compared the geometric mean titers (GMTs), geometric mean antibody fold increases (GMIs) and seroconversion rates of poliovirus type-specific neutralizing antibodies after vaccination among participants with different maternal poliovirus antibody levels. RESULTS: The GMTs and GMIs of three types of poliovirus antibodies after vaccination in maternal antibody negative participants were significantly higher than those in maternal antibody positive participants. The seroconversion rates of type II and type III poliovirus antibodies in maternal antibody positive participants were significantly lower than those in maternal antibody negative participants. Among participants with maternal antibody titer < 1:8, 1:8 ~ < 1:32 and ≥ 1:32, the GMTs and GMIs of three types of poliovirus antibodies after vaccination showed a tendency to decline with the increasing of maternal antibody levels. The seroconversion rates of three types of poliovirus antibodies in participants with maternal antibody titer ≥1:32 were significantly lower than those in participants with maternal antibody titer < 1:8 and 1:8 ~ < 1:32. CONCLUSIONS: Maternal poliovirus antibodies interfered with the immune responses of infants to poliovirus vaccines, and a high level of maternal antibodies exhibited a greater dampening effect. TRIAL REGISTRATION: ClinicalTrials.gov NCT04264598 February 11, 2020; ClinicalTrials.gov NCT04264546 February 11, 2020; ClinicalTrials.gov NCT03902054 April 3, 2019. Retrospectively registered.


Assuntos
Anticorpos Antivirais/imunologia , Imunidade Materno-Adquirida/imunologia , Imunogenicidade da Vacina , Poliomielite/prevenção & controle , Vacina Antipólio de Vírus Inativado/uso terapêutico , Poliovirus/imunologia , Vacinação/métodos , Anticorpos Neutralizantes/imunologia , China , Feminino , Humanos , Lactente , Masculino , Poliomielite/virologia , Vacina Antipólio de Vírus Inativado/efeitos adversos , Soroconversão
3.
Acta Biomed ; 91(3): e2020031, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32921733

RESUMO

The COVID-19 pandemic and response caused a worrying decline in vaccine uptake around the world. In Italy, the immunization coverage targets set in the 2017-19 National Immunization Prevention Plan (PNPV) have been met only partially. The current public health emergency is likely to have negatively impacted on immunization , with the risk of re-occurrence of Vaccine-Preventable Diseases (VPDs) outbreaks. As flu season approaches, both National Health Institutions  and the scientific community in Italy have taken action. Well in advance as compared to previous years, the Ministry of Health released  the Circular to launch the 2020-2021 influenza immunization campaign which this year is longer (starting on October 2020) and extends flu vaccine recommendations to more  "at risk" subgroups, offered the vaccine free of charge. In addition, some Italian Regions have recently tried to make  flu vaccination compulsory for all Healthcare Workers (HCWs). Since 2017, when the law on childhood vaccination in Italy was passed, compulsory vaccination has proved to be a successful strategy towards coverage increase.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Vacinas contra Influenza/farmacologia , Influenza Humana/prevenção & controle , Influenzavirus A/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Vacinação/métodos , Comorbidade , Saúde Global , Pessoal de Saúde , Humanos , Influenza Humana/epidemiologia
5.
Artigo em Inglês | MEDLINE | ID: mdl-32756371

RESUMO

Ecological studies have suggested fewer COVID-19 morbidities and mortalities in Bacillus Calmette-Guérin (BCG)-vaccinated countries than BCG-non-vaccinated countries. However, these studies obtained data during the early phase of the pandemic and did not adjust for potential confounders, including PCR-test numbers per population (PCR-tests). Currently-more than four months after declaration of the pandemic-the BCG-hypothesis needs reexamining. An ecological study was conducted by obtaining data of 61 factors in 173 countries, including BCG vaccine coverage (%), using morbidity and mortality as outcomes, obtained from open resources. 'Urban population (%)' and 'insufficient physical activity (%)' in each country was positively associated with morbidity, but not mortality, after adjustment for PCR-tests. On the other hand, recent BCG vaccine coverage (%) was negatively associated with mortality, but not morbidity, even with adjustment for percentage of the population ≥ 60 years of age, morbidity, PCR-tests and other factors. The results of this study generated a hypothesis that a national BCG vaccination program seems to be associated with reduced mortality of COVID-19, although this needs to be further examined and proved by randomized clinical trials.


Assuntos
Vacina BCG/administração & dosagem , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/mortalidade , Pneumonia Viral/mortalidade , Infecções por Coronavirus/virologia , Humanos , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Pneumonia Viral/virologia , Projetos de Pesquisa , Vacinação/métodos
6.
Pharmazie ; 75(8): 375-380, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32758336

RESUMO

Diabetes mellitus (DM) is one of the major risk factors for COVID-19 complications as it is one of the chronic immune-compromising conditions especially if patients have uncontrolled diabetes, poor HbA1c and/or irregular blood glucose levels. Diabetic patients' mortality rates with COVID-19 are higher than those of cardiovascular or cancer patients. Recently, Bacillus Calmette-Guérin (BCG) vaccine has shown successful results in reversing diabetes in both rats and clinical trials based on different mechanisms from aerobic glycolysis to beta cells regeneration. BCG is a multi-face vaccine that has been used extensively in protection from tuberculosis (TB) and leprosy and has been repositioned for treatment of bladder cancer, diabetes and multiple sclerosis. Recently, COVID-19 epidemiological studies confirmed that universal BCG vaccination reduced morbidity and mortality in certain geographical areas. Countries without universal policies of BCG vaccination (Italy, Nederland, USA) have been more severely affected compared to countries with universal and long-standing BCG policies that have shown low numbers of reported COVID-19 cases. Some countries have started clinical trials that included a single dose BCG vaccine as prophylaxis from COVID-19 or an attempt to minimize its side effects. This proposed research aims to use BCG vaccine as a double-edged weapon countering both COVID-19 and diabetes, not only as protection but also as therapeutic vaccination. The work includes a case study of regenerated pancreatic beta cells based on improved C-peptide and PCPRI laboratory findings after BCG vaccination for a 9 year old patient. The patient was re-vaccinated based on a negative tuberculin test and no scar at the site of injection of the 1st BCG vaccination at birth. The authors suggest and invite the scientific community to take into consideration the concept of direct BCG re-vaccination (after 4 weeks) because of the reported gene expressions and exaggerated innate immunity consequently. As the diabetic MODY-5 patient (mutation of HNF1B, Val2Leu) was on low dose Riomet® while eliminating insulin gradually, a simple analytical method for metformin assay was recommended to ensure its concentration before use as it is not approved yet by the Egyptian QC labs.


Assuntos
Vacina BCG/administração & dosagem , Infecções por Coronavirus/imunologia , Diabetes Mellitus/imunologia , Células Secretoras de Insulina/citologia , Pneumonia Viral/imunologia , Animais , Vacina BCG/imunologia , Criança , Infecções por Coronavirus/complicações , Diabetes Mellitus/fisiopatologia , Humanos , Masculino , Pandemias , Pneumonia Viral/complicações , Ratos , Regeneração/imunologia , Fatores de Risco , Vacinação/métodos
7.
BMC Infect Dis ; 20(1): 627, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32842988

RESUMO

BACKGROUND: The epidemiological pattern of hepatitis A infection has shown dynamic changes in many parts of the world due to improved socio-economic conditions and the accumulation of seronegative subjects, which leads to possible outbreaks and increased morbidity rate. In Tunisia, the epidemiological status of hepatits A virus is currently unknown. However, over the past years higher numbers of symptomatic hepatitis A virus infection in school attendants and several outbreaks were reported to the Ministry of Health, especially from regions with the lowest socio-economic levels in the country. The aim of this study was to investigate the current seroprevalence of hepatitis A virus antibodies in central-west Tunisia and assess the impact of hepatitis A virus vaccination on hepatitis A epidemiology. METHODS: Serum samples from 1379 individuals, aged 5-75 years, were screened for hepatitis A virus antibodies. Adjusted seroprevalence, incidence and force of infection parameters were estimated by a linear age structured SEIR (Susceptible-Exposed-Infectious-Recovered) compartmental model. A vaccine model was then constructed to assess the impact on hepatitis A virus epidemiology of 3 scenarios of vaccination strategies: one dose at 12-months of age, one dose at 6-years and one dose at 12-months and another at 6-years of age during 6 years. RESULTS: A rapid increase in anti-hepatitis A virus seroprevalence was noted during infancy and adolescence: 47% of subjects under 10-years-old are infected; the prevalence increases to 77% at 15-years and reaches 97% in subjects aged 30-years. The force of infection is highest between 10 and 30-years of age and the incidence declines with increasing age. The vaccine model showed that the 3-scenarios lead to a significant reduction of the fraction of susceptibles. The two doses scenario gives the best results. Single-dose vaccination at 6-years of age provides more rapid decrease of disease burden in school-aged children, as compared to single-dose vaccination at 12-months, but keeps with a non-negligible fraction of susceptibles among children < 6-years. CONCLUSIONS: Our study confirms the epidemiological switch from high to intermediate endemicity of hepatitis A virus in Tunisia and provides models that may help undertake best decisions in terms of vaccinations strategies.


Assuntos
Vírus da Hepatite A/imunologia , Hepatite A/epidemiologia , Hepatite A/transmissão , Modelos Teóricos , Vacinação/métodos , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Pré-Escolar , Feminino , Hepatite A/sangue , Hepatite A/prevenção & controle , Anticorpos Anti-Hepatite A/sangue , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos , Tunísia/epidemiologia , Adulto Jovem
8.
Am J Prev Med ; 59(4): 493-503, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778354

RESUMO

INTRODUCTION: Given the continuing COVID-19 pandemic and much of the U.S. implementing social distancing owing to the lack of alternatives, there has been a push to develop a vaccine to eliminate the need for social distancing. METHODS: In 2020, the team developed a computational model of the U.S. simulating the spread of COVID-19 coronavirus and vaccination. RESULTS: Simulation experiments revealed that to prevent an epidemic (reduce the peak by >99%), the vaccine efficacy has to be at least 60% when vaccination coverage is 100% (reproduction number=2.5-3.5). This vaccine efficacy threshold rises to 70% when coverage drops to 75% and up to 80% when coverage drops to 60% when reproduction number is 2.5, rising to 80% when coverage drops to 75% when the reproduction number is 3.5. To extinguish an ongoing epidemic, the vaccine efficacy has to be at least 60% when coverage is 100% and at least 80% when coverage drops to 75% to reduce the peak by 85%-86%, 61%-62%, and 32% when vaccination occurs after 5%, 15%, and 30% of the population, respectively, have already been exposed to COVID-19 coronavirus. A vaccine with an efficacy between 60% and 80% could still obviate the need for other measures under certain circumstances such as much higher, and in some cases, potentially unachievable, vaccination coverages. CONCLUSIONS: This study found that the vaccine has to have an efficacy of at least 70% to prevent an epidemic and of at least 80% to largely extinguish an epidemic without any other measures (e.g., social distancing).


Assuntos
Controle de Doenças Transmissíveis , Simulação por Computador , Infecções por Coronavirus , Pandemias , Pneumonia Viral , Vacinação , Vacinas Virais/farmacologia , Betacoronavirus/isolamento & purificação , Controle de Doenças Transmissíveis/métodos , Controle de Doenças Transmissíveis/estatística & dados numéricos , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Erradicação de Doenças/métodos , Erradicação de Doenças/estatística & dados numéricos , Humanos , Determinação de Necessidades de Cuidados de Saúde , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Resultado do Tratamento , Estados Unidos/epidemiologia , Vacinação/métodos , Vacinação/estatística & dados numéricos , Cobertura Vacinal , Vacinas Virais/normas
9.
PLoS Med ; 17(8): e1003238, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32810149

RESUMO

BACKGROUND: It is estimated that vaccinating 50%-70% of school-aged children for influenza can produce population-wide indirect effects. We evaluated a city-wide school-located influenza vaccination (SLIV) intervention that aimed to increase influenza vaccination coverage. The intervention was implemented in ≥95 preschools and elementary schools in northern California from 2014 to 2018. Using a matched cohort design, we estimated intervention impacts on student influenza vaccination coverage, school absenteeism, and community-wide indirect effects on laboratory-confirmed influenza hospitalizations. METHODS AND FINDINGS: We used a multivariate matching algorithm to identify a nearby comparison school district with pre-intervention characteristics similar to those of the intervention school district and matched schools in each district. To measure student influenza vaccination, we conducted cross-sectional surveys of student caregivers in 22 school pairs (2017 survey, N = 6,070; 2018 survey, N = 6,507). We estimated the incidence of laboratory-confirmed influenza hospitalization from 2011 to 2018 using surveillance data from school district zip codes. We analyzed student absenteeism data from 2011 to 2018 from each district (N = 42,487,816 student-days). To account for pre-intervention differences between districts, we estimated difference-in-differences (DID) in influenza hospitalization incidence and absenteeism rates using generalized linear and log-linear models with a population offset for incidence outcomes. Prior to the SLIV intervention, the median household income was $51,849 in the intervention site and $61,596 in the comparison site. The population in each site was predominately white (41% in the intervention site, 48% in the comparison site) and/or of Hispanic or Latino ethnicity (26% in the intervention site, 33% in the comparison site). The number of students vaccinated by the SLIV intervention ranged from 7,502 to 10,106 (22%-28% of eligible students) each year. During the intervention, influenza vaccination coverage among elementary students was 53%-66% in the comparison district. Coverage was similar between the intervention and comparison districts in influenza seasons 2014-2015 and 2015-2016 and was significantly higher in the intervention site in seasons 2016-2017 (7%; 95% CI 4, 11; p < 0.001) and 2017-2018 (11%; 95% CI 7, 15; p < 0.001). During seasons when vaccination coverage was higher among intervention schools and the vaccine was moderately effective, there was evidence of statistically significant indirect effects: The DID in the incidence of influenza hospitalization per 100,000 in the intervention versus comparison site was -17 (95% CI -30, -4; p = 0.008) in 2016-2017 and -37 (95% CI -54, -19; p < 0.001) in 2017-2018 among non-elementary-school-aged individuals and -73 (95% CI -147, 1; p = 0.054) in 2016-2017 and -160 (95% CI -267, -53; p = 0.004) in 2017-2018 among adults 65 years or older. The DID in illness-related school absences per 100 school days during the influenza season was -0.63 (95% CI -1.14, -0.13; p = 0.014) in 2016-2017 and -0.80 (95% CI -1.28, -0.31; p = 0.001) in 2017-2018. Limitations of this study include the use of an observational design, which may be subject to unmeasured confounding, and caregiver-reported vaccination status, which is subject to poor recall and low response rates. CONCLUSIONS: A city-wide SLIV intervention in a large, diverse urban population was associated with a decrease in the incidence of laboratory-confirmed influenza hospitalization in all age groups and a decrease in illness-specific school absence rate among students in 2016-2017 and 2017-2018, seasons when the vaccine was moderately effective, suggesting that the intervention produced indirect effects. Our findings suggest that in populations with moderately high background levels of influenza vaccination coverage, SLIV programs are associated with further increases in coverage and reduced influenza across the community.


Assuntos
Absenteísmo , Vacinas contra Influenza/administração & dosagem , Serviços de Saúde Escolar/normas , População Urbana , Cobertura Vacinal/normas , Vacinação/normas , Adolescente , California/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Masculino , Instituições Acadêmicas/normas , Estudantes , Vacinação/métodos , Cobertura Vacinal/métodos
10.
PLoS One ; 15(8): e0237745, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817627

RESUMO

BACKGROUND: Cervical cancer is the second most common female reproductive cancer after breast cancer with 84% of the cases in developing countries. A high uptake of human papilloma virus (HPV) vaccination and screening, and early diagnosis leads to a reduction of incidence and mortality rates. Yet uptake of screening is low in Sub-Saharan Africa and there is an increasing number of women presenting for treatment with advanced disease. Nine women in their twenties die from cervical cancer in Kenya every day. This paper presents the biopsychosocial risk factors that impact on cervical cancer knowledge among Kenyan women aged 15 to 24 years. The findings will highlight opportunities for early interventions to prevent the worrying prediction of an exponential increase by 50% of cervical cancer incidences in the younger age group by 2034. METHODS: Data from the 2014 Kenya Demographic and Health Survey (KDHS) was analysed using complex sample logistic regression to assess biopsychosocial risk factors of knowledge of cervical cancer among young women aged 15 to 24 years (n = 5398). FINDINGS: Close to one third of the participants were unaware of cervical cancer with no difference between participants aged 15-19 years (n = 2716) and those aged 20-24 years (n = 2691) (OR = 1; CI = 0.69-1.45). Social predisposing factors, such as lack of education; poverty; living further from a health facility; or never having taken a human immunodeficiency virus (HIV) test, were significantly associated with lack of awareness of cervical cancer (p<0.001). Young women who did not know where to obtain condoms had an OR of 2.12 (CI 1.72-2.61) for being unaware of cervical cancer. Psychological risk factors, such as low self-efficacy about seeking medical help, and an inability to refuse unsafe sex with husband or partner, perpetuated the low level of awareness about cervical cancer (p<0.001). CONCLUSIONS: A considerable proportion of young women in Kenya are unaware of cervical cancer which is associated with a variety of social and psychological factors. We argue that the high prevalence of cervical cancer and poor screening rates will continue to prevail among older women if issues that affect young women's awareness of cervical cancer are not addressed. Given that the Kenyan youth are exposed to HPV due to early sexual encounters and a high prevalence of HIV, targeted interventions are urgently needed to increase the uptake of HPV vaccination and screening.


Assuntos
Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/psicologia , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/psicologia , Adolescente , Adulto , Detecção Precoce de Câncer , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Quênia/epidemiologia , Modelos Logísticos , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/virologia , Fatores de Risco , Autoeficácia , Parceiros Sexuais , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/virologia , Vacinação/métodos , Esfregaço Vaginal , Adulto Jovem
11.
Expert Rev Vaccines ; 19(8): 691-698, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32838605

RESUMO

INTRODUCTION: The world is currently fighting a COVID-19 pandemic, perhaps the most disruptive infectious disease outbreak since the 1918 Spanish influenza. Governments have taken drastic measures to curb the spread of SARS-CoV-2, and the development of safe and efficacious vaccine candidates is being accelerated. The possibility of vaccine-mediated disease enhancement with coronavirus vaccines has been flagged as a potential safety concern, and, despite the urgent need, should be thoroughly assessed as vaccines against SARS-CoV-2 are being tested. AREA COVERED: We review the in vivo evidence suggesting a theoretical risk of disease enhancement after vaccination with SARS-CoV and MERS-CoV vaccine candidates. We also identify knowledge gaps that need to be filled to maximize the chance of developing a safe vaccine and minimize the risk of encountering disease enhancement in vaccinated individuals after exposure to SARS-CoV-2. EXPERT OPINION: We compile and propose avenues to investigate the risk of vaccine-mediated disease enhancement both during pre-clinical and early clinical development. While the pressing need for a vaccine against COVID-19 (and future epidemic coronaviruses) cannot be ignored, we advocate to keep safety at the center of the debate. Protecting individuals with effective and safe vaccines should be a priority, even during extraordinary times like the COVID-19 pandemic.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/administração & dosagem , Animais , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Humanos , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Vacinação/efeitos adversos , Vacinação/métodos , Vacinas Virais/efeitos adversos
13.
BMC Infect Dis ; 20(1): 528, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32698884

RESUMO

BACKGROUND: Hepatitis B virus (HBV) infection is one of the major public health problems worldwide. Limited information exists about the epidemiology of HBV infection in Ethiopia. This study aimed to assess sero-prevalence of HBV markers and associated factors in children living in Hawassa City, southern Ethiopia. METHODS: A community-based cross-sectional study was conducted among 471 children in Hawassa City, southern Ethiopia from May to September, 2018. A total of 471 children were included in the study using a multistage sampling technique. Data on demographic and risk factors were gathered using structured questionnaires. Blood samples were collected and sera were screened for hepatitis B surface antigen (HBsAg), antibody to core antigen (anti-HBc), and antibody against surface antigen (anti-HBs) using enzyme-linked immunosorbent assay. RESULTS: The sero-prevalence of HBsAg, anti-HBc, and anti-HBs markers among children were 4.4, 19.5 and 20.0%, respectively. Children at higher risk of having HBsAg marker were those who had a history of injectable medications (AOR 5.02, 95% CI: 1.14, 22.07), a family history of liver disease (AOR 6.37, 95% CI: 1.32, 30.74), a HBsAg seropositive mothers, (AOR 11.19, (95% CI: 3.15, 39.67), and had no vaccination history for HBV (AOR, 6.37, 95% CI: 1.32, 30.74). Children from families with low monthly income, who were home delivered, unvaccinated for HBV or with HBsAg seropositive mother had increased risk of having anti-HBc. CONCLUSIONS: The study findings showed an intermediate endemicity of HBV infection in the study setting. The observed rate of residual HBV infection with low rate of immunized children after HBV vaccination was high. Hence, introducing birth dose vaccine, safe injection practice and improving immunization coverage during pregnancy as part of the antenatal care package should be considered. Furthermore, governmental and non-governmental organizations should give attention on timely measures for the prevention of ongoing vertical transmission from mother to child as well as early horizontal transmission of HBV in Hawassa City, Ethiopia.


Assuntos
Vírus da Hepatite B/imunologia , Hepatite B/sangue , Hepatite B/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Biomarcadores/sangue , Criança , Pré-Escolar , Estudos Transversais , Etiópia/epidemiologia , Feminino , Hepatite B/prevenção & controle , Hepatite B/transmissão , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Vacinas contra Hepatite B/administração & dosagem , Humanos , Transmissão Vertical de Doença Infecciosa/prevenção & controle , Masculino , Gravidez , Complicações Infecciosas na Gravidez/sangue , Complicações Infecciosas na Gravidez/prevenção & controle , Complicações Infecciosas na Gravidez/virologia , Cuidado Pré-Natal/métodos , Prevalência , Fatores de Risco , Inquéritos e Questionários , Vacinação/métodos
14.
J Theor Biol ; 505: 110422, 2020 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-32717195

RESUMO

For various infectious diseases, vaccination has become a major intervention strategy. However, the importance of social distancing has recently been highlighted during the ongoing COVID-19 pandemic. In the absence of vaccination, or when vaccine efficacy is poor, social distancing may help to curb the spread of new virus strains. However, both vaccination and social distancing are associated with various costs. It is critical to consider these costs in addition to the benefits of these strategies when determining the optimal rates of application of control strategies. We developed a game-theoretic epidemiological model that considers vaccination and social distancing under the assumption that individuals pursue the maximization of payoffs. By using this model, we identified the individually optimal strategy based on the Nash strategy when both strategies are available and when only one strategy is available. Furthermore, we determined the relative costs of control strategies at which individuals preferentially adopt vaccination over social distancing (or vice versa).


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Teoria do Jogo , Modelos Teóricos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Distância Social , Vacinação/métodos , Comportamento de Escolha , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/terapia , Humanos , Pneumonia Viral/epidemiologia , Pneumonia Viral/terapia
15.
Respir Res ; 21(1): 178, 2020 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-32653040

RESUMO

Bacillus Calmette-Guérin (BCG) vaccination is routine and near-universal in many low- and middle-income countries (LMIC). It has been suggested that BCG can have a protective effect on COVID-19 morbidity and mortality. This commentary discusses the limitations of the evidence around BCG and COVID-19. We argue that higher-quality evidence is necessary to understand the protective effect of the BCG vaccine from existing, secondary data, while we await results from clinical trials currently conducted in different settings.


Assuntos
Vacina BCG/imunologia , Vacina BCG/uso terapêutico , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/terapia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/terapia , Controle de Qualidade , Ensaios Clínicos como Assunto , Infecções por Coronavirus/mortalidade , Análise Custo-Benefício , Feminino , Humanos , Masculino , Determinação de Necessidades de Cuidados de Saúde , Pneumonia Viral/mortalidade , Pobreza , Prevenção Primária/métodos , Papel (figurativo) , Fatores Socioeconômicos , Análise de Sobrevida , Vacinação/métodos , Vacinação/estatística & dados numéricos
16.
Life Sci ; 257: 118056, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32645344

RESUMO

Various human pathogenic viruses employ envelope glycoproteins for host cell receptor recognition and binding, membrane fusion and viral entry. The spike (S) glycoprotein of betacoronavirus SARS-CoV-2 is a homotrimeric class I fusion protein that exists in a metastable conformation for cleavage by host cell proteases furin and TMPRSS2, thereby undergoing substantial structural rearrangement for ACE2 host cell receptor binding and subsequent viral entry by membrane fusion. The S protein is densely decorated with N-linked glycans protruding from the trimer surface that affect S protein folding, processing by host cell proteases and the elicitation of humoral immune response. Deep insight into the sophisticated structure of SARS-CoV-2 S protein may provide a blueprint for vaccination strategies, as reviewed herein.


Assuntos
Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/imunologia , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/patologia , Infecções por Coronavirus/prevenção & controle , Humanos , Pandemias/prevenção & controle , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/patologia , Pneumonia Viral/prevenção & controle , Ligação Proteica , Receptores Virais/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Vacinação/métodos , Internalização do Vírus
17.
Life Sci ; 257: 118058, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653518

RESUMO

SARS-CoV-2 is a new member of coronaviruses that its sudden spreading put the health care system of most countries in a tremendous shock. For controlling of the new infection, COVID-19, many efforts have been done and are ongoing to defeat this virus in the combat field. In this review, we focused on how the immune system behaves toward the virus and the relative possible consequences during their interactions. Then the therapeutic steps and potential vaccine candidates have been described in a hope to provide a better prospective of effective treatment and preventive strategies to the novel SARS-CoV in near future.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/imunologia , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/imunologia , Betacoronavirus/patogenicidade , Coronavirus/imunologia , Coronavirus/patogenicidade , Infecções por Coronavirus/patologia , Citocinas/efeitos dos fármacos , Citocinas/imunologia , Citocinas/metabolismo , Humanos , Pandemias , Pneumonia Viral/patologia , Vacinação/métodos
18.
Cell ; 182(3): 722-733.e11, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32645327

RESUMO

Vaccines are urgently needed to control the ongoing pandemic COVID-19 and previously emerging MERS/SARS caused by coronavirus (CoV) infections. The CoV spike receptor-binding domain (RBD) is an attractive vaccine target but is undermined by limited immunogenicity. We describe a dimeric form of MERS-CoV RBD that overcomes this limitation. The RBD-dimer significantly increased neutralizing antibody (NAb) titers compared to conventional monomeric form and protected mice against MERS-CoV infection. Crystal structure showed RBD-dimer fully exposed dual receptor-binding motifs, the major target for NAbs. Structure-guided design further yielded a stable version of RBD-dimer as a tandem repeat single-chain (RBD-sc-dimer) which retained the vaccine potency. We generalized this strategy to design vaccines against COVID-19 and SARS, achieving 10- to 100-fold enhancement of NAb titers. RBD-sc-dimers in pilot scale production yielded high yields, supporting their scalability for further clinical development. The framework of immunogen design can be universally applied to other beta-CoV vaccines to counter emerging threats.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vírus da SARS/imunologia , Design Universal , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/química , Linhagem Celular Tumoral , Chlorocebus aethiops , Infecções por Coronavirus/virologia , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Coronavírus da Síndrome Respiratória do Oriente Médio/química , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/virologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas/imunologia , Receptores Virais/metabolismo , Vírus da SARS/química , Células Sf9 , Organismos Livres de Patógenos Específicos , Spodoptera , Transfecção , Vacinação/métodos , Células Vero , Vacinas Virais
19.
Lancet ; 395(10242): 1998-2007, 2020 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-32534628

RESUMO

BACKGROUND: In animal models, immunity to mosquito salivary proteins protects animals against mosquito-borne disease. These findings provide a rationale to vaccinate against mosquito saliva instead of the pathogen itself. To our knowledge, no vector salivary protein-based vaccine has been tested for safety and immunogenicity in humans. We aimed to assess the safety and immunogenicity of Anopheles gambiae saliva vaccine (AGS-v), a peptide-based vaccine derived from four A gambiae salivary proteins, in humans. METHODS: In this randomised, placebo-controlled, double-blind, phase 1 trial, participants were enrolled at the National Institutes of Health Clinical Center in Bethesda, MD, USA. Participants were eligible if they were healthy adults, aged 18-50 years with no history of severe allergic reactions to mosquito bites. Participants were randomly assigned (1:1:1), using block randomisation and a computer-generated randomisation sequence, to treatment with either 200 nmol of AGS-v vaccine alone, 200 nmol of AGS-v with adjuvant (Montanide ISA 51), or sterile water as placebo. Participants and clinicians were masked to treatment assignment. Participants were given a subcutaneous injection of their allocated treatment at day 0 and day 21, followed by exposure to feeding by an uninfected Aedes aegypti mosquito at day 42 to assess subsequent risk to mosquito bites in a controlled setting. The primary endpoints were safety and immunogenicity at day 42 after the first immunisation. Participants who were given at least one dose of assigned treatment were assessed for the primary endpoints and analysis was by intention to treat. The trial was registered with ClinicalTrials.gov, NCT03055000, and is closed for accrual. FINDINGS: Between Feb 15 and Sept 10, 2017, we enrolled and randomly assigned 49 healthy adult participants to the adjuvanted vaccine (n=17), vaccine alone (n=16), or placebo group (n=16). Five participants did not complete the two-injection regimen with mosquito feeding at day 42, but were included in the safety analyses. No systemic safety concerns were identified; however, one participant in the adjuvanted vaccine group developed a grade 3 erythematous rash at the injection site. Pain, swelling, erythema, and itching were the most commonly reported local symptoms and were significantly increased in the adjuvanted vaccine group compared with both other treatment groups (nine [53%] of 17 participants in the adjuvanted vaccine group, two [13%] of 16 in the vaccine only group, and one [6%] of 16 in the placebo group; p=0·004). By day 42, participants who were given the adjuvanted vaccine had a significant increase in vaccine-specific total IgG antibodies compared with at baseline than did participants who were give vaccine only (absolute difference of log10-fold change of 0·64 [95% CI 0·39 to 0·89]; p=0·0002) and who were given placebo (0·62 [0·34 to 0·91]; p=0·0001). We saw a significant increase in IFN-γ production by peripheral blood mononuclear cells at day 42 in the adjuvanted vaccine group compared with in the placebo group (absolute difference of log10 ratio of vaccine peptide-stimulated vs negative control 0·17 [95% CI 0·061 to 0·27]; p=0·009) but we saw no difference between the IFN-γ production in the vaccine only group compared with the placebo group (0·022 [-0·072 to 0·116]; p=0·63). INTERPRETATION: AGS-v was well tolerated, and, when adjuvanted, immunogenic. These findings suggest that vector-targeted vaccine administration in humans is safe and could be a viable option for the increasing burden of vector-borne disease. FUNDING: Office of the Director and the Division of Intramural Research at the National Institute of Allergy and Infectious Diseases, and National Institutes of Health.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Transmissão de Doença Infecciosa/prevenção & controle , Imunogenicidade da Vacina/imunologia , Saliva/imunologia , Adjuvantes Imunológicos/efeitos adversos , Adulto , Animais , Anopheles/imunologia , Anopheles/metabolismo , Estudos de Casos e Controles , Método Duplo-Cego , Feminino , Humanos , Imunoglobulina G/imunologia , Injeções Subcutâneas/métodos , Leucócitos Mononucleares/imunologia , Masculino , Modelos Animais , Mosquitos Vetores/imunologia , Mosquitos Vetores/metabolismo , Placebos/administração & dosagem , Segurança , Vacinação/efeitos adversos , Vacinação/métodos
20.
PLoS One ; 15(6): e0233840, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555601

RESUMO

BACKGROUND: Immunization with radiation-attenuated sporozoites (RAS) by mosquito bite provides >90% sterile protection against Plasmodium falciparum (Pf) malaria in humans. RAS invade hepatocytes but do not replicate. CD8+ T cells recognizing parasite-derived peptides on the surface of infected hepatocytes are likely the primary protective mechanism. We conducted a randomized clinical trial of RAS immunization to assess safety, to achieve 50% vaccine efficacy (VE) against controlled human malaria infection (CHMI), and to generate reagents from protected and non-protected subjects for future identification of protective immune mechanisms and antigens. METHODS: Two cohorts (Cohort 1 and Cohort 2) of healthy, malaria-naïve, non-pregnant adults age 18-50 received five monthly immunizations with infected (true-immunized, n = 21) or non-infected (mock-immunized, n = 5) mosquito bites and underwent homologous CHMI at 3 weeks. Immunization parameters were selected for 50% protection based on prior clinical data. Leukapheresis was done to collect plasma and peripheral blood mononuclear cells. RESULTS: Adverse event rates were similar in true- and mock-immunized subjects. Two true- and two mock-immunized subjects developed large local reactions likely caused by mosquito salivary gland antigens. In Cohort 1, 11 subjects received 810-1235 infected bites; 6/11 (55%) were protected against CHMI vs. 0/3 mock-immunized and 0/6 infectivity controls (VE 55%). In Cohort 2, 10 subjects received 839-1131 infected bites with a higher first dose and a reduced fifth dose; 9/10 (90%) were protected vs. 0/2 mock-immunized and 0/6 controls (VE 90%). Three/3 (100%) protected subjects administered three booster immunizations were protected against repeat CHMI vs. 0/6 controls (VE 100%). Cohort 2 uniquely showed a significant rise in IFN-γ responses after the third and fifth immunizations and higher antibody responses to CSP. CONCLUSIONS: PfRAS were generally safe and well tolerated. Cohort 2 had a higher first dose, reduced final dose, higher antibody responses to CSP and significant rise of IFN-γ responses after the third and fifth immunizations. Whether any of these factors contributed to increased protection in Cohort 2 requires further investigation. A cryobank of sera and cells from protected and non-protected individuals was generated for future immunological studies and antigen discovery. TRIAL REGISTRATION: ClinicalTrials.gov NCT01994525.


Assuntos
Mordeduras e Picadas de Insetos/imunologia , Malária/prevenção & controle , Esporozoítos/imunologia , Vacinação/métodos , Vacinas Atenuadas/efeitos adversos , Adulto , Animais , Anopheles/parasitologia , Anopheles/fisiologia , Feminino , Raios gama , Humanos , Malária/imunologia , Masculino , Pessoa de Meia-Idade , Mosquitos Vetores/parasitologia , Mosquitos Vetores/fisiologia , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/imunologia , Plasmodium falciparum/patogenicidade , Proteínas de Protozoários/imunologia , Esporozoítos/patogenicidade , Esporozoítos/efeitos da radiação , Vacinação/efeitos adversos
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