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1.
PLoS One ; 18(9): e0291730, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37733724

RESUMO

Mumps is an acute infectious disease, which was well controlled in the past, but recently it has resurged in some areas. This study aimed to evaluate the safety profile of the live attenuated mumps vaccine after large-scale vaccination. We conducted an observational, open-label phase 4 trial in Shaanxi, China from October 2020 to March 2021. Eligible participants were freshmen of junior high school who were not above 14 years old. Adverse events following immunization (AEFI) monitoring was carried out by active and passive surveillance. Safety follow-ups were conducted during the study participation. Overall, 10057 subjects were enrolled in the active surveillance analysis. A total of 214 subjects reported adverse reactions with an incidence of 2.13% (214/10057). Most adverse reactions were grade 1, and the incidence of grade 1 adverse reactions was 1.44% (145/10057); 0.60% for grade 2 (60/10057); and 0.09% for grade 3 (9/10057). The majority of adverse reactions were solicited (1.73%, 174/10057). Injection-site pain was the most frequently reported local adverse reaction (0.71%, 71/10057), followed by redness (0.29%, 29/10057). The most common systemic adverse reactions were nausea (0.19%, 19/10057) and fever (0.16%, 16/10057). For passive AEFI surveillance, 57 AEFI cases were reported, with an incidence of 19.28/100000 (57/287608). And most AEFI cases were common adverse reactions (66.67%, 38/57). In total, the live attenuated mumps vaccine evaluated in this trial has a favorable safety profile and can be used for large-scale inoculation.


Assuntos
Imunização , Vacinação , Humanos , Adolescente , Vacinação/efeitos adversos , China/epidemiologia , Febre , Vacina contra Caxumba/efeitos adversos
2.
Vaccine ; 41(22): 3467-3471, 2023 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-37127526

RESUMO

BACKGROUND: Sabin strain inactivated poliovirus vaccine (hereinafter as "sIPV") has been marketed globally in recent years, and more data on its immune persistence are needed. METHODS: This is a phase IV, open-labeled, parallel-controlled observational study based on phase III clinical trial as required by the China National Medical Products Administration (NMPA). At least 450 subjects aged four years (48-54 months) who received four doses at 2, 3, 4 and 18 months of age of sIPV or wild strain poliovirus vaccine (wIPV) in phase III clinical trial enrolled at a 2:1 ratio and collected blood samples for neutralizing antibody testing. RESULTS: A total of 500 subjects of four years old (334 in the sIPV group and 166 in wIPV group) were finally enrolled. The seropositivity rates (≥1:8) of neutralizing antibodies against serotype I-III were all 100.00% in all participants, and the geometric mean titers (GMT) were 1117.33 vs. 337.77 against serotype I, 632.72 vs. 267.34 against serotype Ⅱ, 1665.98 vs. 923.02 against serotype III in the sIPV group and wIPV group respectively at 4 years old. The seropositivity rates and GMTs of neutralizing antibodies in the test group were non-inferior to that of the control group against all three serotypes at different time points (P < 0.0001). The antibody GMT experienced a 10-fold, 8-fold, and 7-fold decline for serotypes I, Ⅱ, and III in the sIPV group, and a 13-fold, 7-fold, and 7-fold decline in the wIPV group from one month after booster vaccination to 4 years old. CONCLUSIONS: The neutralizing antibody level is much higher than the seroprotection cutoff (≥1:8) among children of 4 years old who completed the four-dose vaccination of either sIPV or wIPV. Therefore, another booster vaccination is not recommended at 4 years old. Longer immune persistence observation is still ongoing. REGISTRATION: ClinicalTrials.gov Identifier: NCT04989231.


Assuntos
Poliomielite , Poliovirus , Humanos , Pré-Escolar , Vacina Antipólio de Vírus Inativado , Poliomielite/prevenção & controle , Vacina Antipólio Oral , Anticorpos Antivirais , Esquemas de Imunização , Anticorpos Neutralizantes , Imunogenicidade da Vacina
3.
EBioMedicine ; 91: 104563, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37099842

RESUMO

BACKGROUND: The Omicron variant has challenged the control of the COVID-19 pandemic due to its immuno-evasive properties. The administration of a booster dose of a SARS-CoV-2 vaccine showed positive effects in the immunogenicity against SARS-CoV-2, effect that is even enhanced after the administration of a second booster. METHODS: During a phase-3 clinical trial, we evaluated the effect of a second booster of CoronaVac®, an inactivated vaccine administered 6 months after the first booster, in the neutralization of SARS-CoV-2 (n = 87). In parallel, cellular immunity (n = 45) was analyzed in stimulated peripheral mononuclear cells by flow cytometry and ELISPOT. FINDINGS: Although a 2.5-fold increase in neutralization of the ancestral SARS-CoV-2 was observed after the second booster when compared with prior its administration (Geometric mean units p < 0.0001; Geometric mean titer p = 0.0002), a poor neutralization against the Omicron variant was detected. Additionally, the activation of specific CD4+ T lymphocytes remained stable after the second booster and, importantly, equivalent activation of CD4+ T lymphocytes against the Omicron variant and the ancestral SARS-CoV-2 were found. INTERPRETATION: Although the neutralizing response against the Omicron variant after the second booster of CoronaVac® was slightly increased, these levels are far from those observed against the ancestral SARS-CoV-2 and could most likely fail to neutralize the virus. In contrast, a robust CD4+T cell response may confer protection against the Omicron variant. FUNDING: The Ministry of Health, Government of Chile, the Confederation of Production and Commerce, Chile and SINOVAC Biotech.NIHNIAID. The Millennium Institute on Immunology and Immunotherapy.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Adulto , Humanos , COVID-19/prevenção & controle , Pandemias , SARS-CoV-2 , Vacinas de Produtos Inativados , Anticorpos Antivirais , Anticorpos Neutralizantes
4.
Elife ; 112022 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-36226829

RESUMO

Background: The development of vaccines to control the coronavirus disease 2019 (COVID-19) pandemic progression is a worldwide priority. CoronaVac is an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine approved for emergency use with robust efficacy and immunogenicity data reported in trials in China, Brazil, Indonesia, Turkey, and Chile. Methods: This study is a randomized, multicenter, and controlled phase 3 trial in healthy Chilean adults aged ≥18 years. Volunteers received two doses of CoronaVac separated by 2 (0-14 schedule) or 4 weeks (0-28 schedule); 2302 volunteers were enrolled, 440 were part of the immunogenicity arm, and blood samples were obtained at different times. Samples from a single center are reported. Humoral immune responses were evaluated by measuring the neutralizing capacities of circulating antibodies. Cellular immune responses were assessed by ELISPOT and flow cytometry. Correlation matrixes were performed to evaluate correlations in the data measured. Results: Both schedules exhibited robust neutralizing capacities with the response induced by the 0-28 schedule being better. No differences were found in the concentration of antibodies against the virus and different variants of concern (VOCs) between schedules. Stimulation of peripheral blood mononuclear cells (PBMCs) with Mega pools of Peptides (MPs) induced the secretion of interferon (IFN)-γ and the expression of activation induced markers in CD4+ T cells for both schedules. Correlation matrixes showed strong correlations between neutralizing antibodies and IFN-γ secretion. Conclusions: Immunization with CoronaVac in Chilean adults promotes robust cellular and humoral immune responses. The 0-28 schedule induced a stronger humoral immune response than the 0-14 schedule. Funding: Ministry of Health, Government of Chile, Confederation of Production and Commerce & Millennium Institute on Immunology and Immunotherapy, Chile. Clinical trial number: NCT04651790.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Esquemas de Imunização , Adulto , Humanos , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19/uso terapêutico , Imunidade Humoral , Interferons , Leucócitos Mononucleares , SARS-CoV-2
5.
mBio ; 13(4): e0142322, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35946814

RESUMO

CoronaVac is an inactivated SARS-CoV-2 vaccine approved by the World Health Organization (WHO). Previous studies reported increased levels of neutralizing antibodies and specific T cells 2 and 4 weeks after two doses of CoronaVac; these levels were significantly reduced at 6 to 8 months after the two doses. Here, we report the effect of a booster dose of CoronaVac on the anti-SARS-CoV-2 immune response generated against the variants of concern (VOCs), Delta and Omicron, in adults participating in a phase III clinical trial in Chile. Volunteers immunized with two doses of CoronaVac in a 4-week interval received a booster dose of the same vaccine between 24 and 30 weeks after the second dose. Neutralization capacities and T cell activation against VOCs Delta and Omicron were assessed 4 weeks after the booster dose. We observed a significant increase in neutralizing antibodies 4 weeks after the booster dose. We also observed a rise in anti-SARS-CoV-2-specific CD4+ T cells over time, and these cells reached a peak 4 weeks after the booster dose. Furthermore, neutralizing antibodies and SARS-CoV-2-specific T cells induced by the booster showed activity against VOCs Delta and Omicron. Our results show that a booster dose of CoronaVac increases adults' humoral and cellular anti-SARS-CoV-2 immune responses. In addition, immunity induced by a booster dose of CoronaVac is active against VOCs, suggesting adequate protection. IMPORTANCE CoronaVac is an inactivated vaccine against SARS-CoV-2 that has been approved by WHO for emergency use. Phase III clinical trials are in progress in several countries, including China, Brazil, Turkey, and Chile, and have shown safety and immunogenicity after two doses of the vaccine. This report characterizes immune responses induced by two doses of CoronaVac followed by a booster dose 5 months after the second dose in healthy Chilean adults. The data reported here show that a booster dose increased the immune responses against SARS-CoV-2, enhancing levels of neutralizing antibodies against the ancestral strain and VOCs. Similarly, anti-SARS-CoV-2 CD4+ T cell responses were increased following the booster dose. In contrast, levels of gamma interferon secretion and T cell activation against the VOCs Delta and Omicron were not significantly different from those for the ancestral strain. Therefore, a third dose of CoronaVac in a homologous vaccination schedule improves its immunogenicity in healthy volunteers.


Assuntos
COVID-19 , Vacinas Virais , Adulto , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , SARS-CoV-2 , Linfócitos T
6.
medRxiv ; 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35441179

RESUMO

Background: CoronaVac ® is an inactivated SARS-CoV-2 vaccine approved by the World Health Organization. Previous studies reported increased levels of neutralizing antibodies and specific T cells two- and four-weeks after two doses of CoronaVac ® , but the levels of neutralizing antibodies are reduced at six to eight months after two doses. Here we report the effect of a booster dose of CoronaVac ® on the anti-SARS-CoV-2 immune response generated against variants of concern (VOC) Delta and Omicron in adults participating in a phase 3 clinical trial in Chile. Methods: Volunteers immunized with two doses of CoronaVac ® in a four-week interval received a booster dose of the same vaccine between twenty-four and thirty weeks after the 2nd dose. Four weeks after the booster dose, neutralizing antibodies and T cell responses were measured. Neutralization capacities and T cell activation against VOC Delta and Omicron were detected at four weeks after the booster dose. Findings: We observed a significant increase in neutralizing antibodies at four weeks after the booster dose. We also observed an increase in CD4 + T cells numbers over time, reaching a peak at four weeks after the booster dose. Furthermore, neutralizing antibodies and SARS-CoV-2 specific T cells induced by the booster showed activity against VOC Delta and Omicron. Interpretation: Our results show that a booster dose of CoronaVac ® increases the anti-SARS-CoV-2 humoral and cellular immune responses in adults. Immunity induced by a booster dose of CoronaVac ® is active against VOC, suggesting an effective protection.

7.
Clin Infect Dis ; 75(1): e792-e804, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34537835

RESUMO

BACKGROUND: The development of effective vaccines against coronavirus disease 2019 is a global priority. CoronaVac is an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine with promising safety and immunogenicity profiles. This article reports safety and immunogenicity results obtained for healthy Chilean adults aged ≥18 years in a phase 3 clinical trial. METHODS: Volunteers randomly received 2 doses of CoronaVac or placebo, separated by 2 weeks. A total of 434 volunteers were enrolled, 397 aged 18-59 years and 37 aged ≥60 years. Solicited and unsolicited adverse reactions were registered from all volunteers. Blood samples were obtained from a subset of volunteers and analyzed for humoral and cellular measures of immunogenicity. RESULTS: The primary adverse reaction in the 434 volunteers was pain at the injection site, with a higher incidence in the vaccine than in the placebo arm. Adverse reactions observed were mostly mild and local. No severe adverse events were reported. The humoral evaluation was performed on 81 volunteers. Seroconversion rates for specific anti-S1-receptor binding domain (RBD) immunoglobulin G (IgG) were 82.22% and 84.44% in the 18-59 year age group and 62.69% and 70.37% in the ≥60 year age group, 2 and 4 weeks after the second dose, respectively. A significant increase in circulating neutralizing antibodies was detected 2 and 4 weeks after the second dose. The cellular evaluation was performed on 47 volunteers. We detected a significant induction of T-cell responses characterized by the secretion of interferon-γ (IFN-γ) upon stimulation with Mega Pools of peptides from SARS-CoV-2. CONCLUSIONS: Immunization with CoronaVac in a 0-14 schedule in Chilean adults aged ≥18 years is safe, induces anti-S1-RBD IgG with neutralizing capacity, activates T cells, and promotes the secretion of IFN-γ upon stimulation with SARS-CoV-2 antigens.


Assuntos
COVID-19 , Vacinas Virais , Adolescente , Adulto , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Chile , Método Duplo-Cego , Humanos , Imunogenicidade da Vacina , Imunoglobulina G , Pessoa de Meia-Idade , SARS-CoV-2 , Vacinas de Produtos Inativados/efeitos adversos , Adulto Jovem
8.
Front Immunol ; 12: 747830, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858404

RESUMO

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible of the current pandemic ongoing all around the world. Since its discovery in 2019, several circulating variants have emerged and some of them are associated with increased infections and death rate. Despite the genetic differences among these variants, vaccines approved for human use have shown a good immunogenic and protective response against them. In Chile, over 70% of the vaccinated population is immunized with CoronaVac, an inactivated SARS-CoV-2 vaccine. The immune response elicited by this vaccine has been described against the first SARS-CoV-2 strain isolated from Wuhan, China and the D614G strain (lineage B). To date, four SARS-CoV-2 variants of concern described have circulated worldwide. Here, we describe the neutralizing capacities of antibodies secreted by volunteers in the Chilean population immunized with CoronaVac against variants of concern Alpha (B.1.1.7), Beta (B.1.351) Gamma (P.1) and Delta (B.617.2). Methods: Volunteers enrolled in a phase 3 clinical trial were vaccinated with two doses of CoronaVac in 0-14 or 0-28 immunization schedules. Sera samples were used to evaluate the capacity of antibodies induced by the vaccine to block the binding between Receptor Binding Domain (RBD) from variants of concern and the human ACE2 receptor by an in-house ELISA. Further, conventional microneutralization assays were used to test neutralization of SARS-CoV-2 infection. Moreover, interferon-γ-secreting T cells against Spike from variants of concern were evaluated in PBMCs from vaccinated subjects using ELISPOT. Results: CoronaVac promotes the secretion of antibodies able to block the RBD of all the SARS-CoV-2 variants studied. Seropositivity rates of neutralizing antibodies in the population evaluated were over 97% for the lineage B strain, over 80% for Alpha and Gamma variants, over 75% for Delta variant and over 60% for the Beta variant. Geometric means titers of blocking antibodies were reduced when tested against SARS-CoV-2 variants as compared to ancestral strain. We also observed that antibodies from vaccinated subjects were able to neutralize the infection of variants D614G, Alpha, Gamma and Delta in a conventional microneutralization assay. Importantly, after SARS-CoV-2 infection, we observed that the blocking capacity of antibodies from vaccinated volunteers increased up to ten times for all the variants tested. We compared the number of interferon-γ-secreting T cells specific for SARS-CoV-2 Spike WT and variants of concern from vaccinated subjects and we did not detect significant differences. Conclusion: Immunization with CoronaVac in either immunization schedule promotes the secretion of antibodies able to block SARS-CoV-2 variants of concern and partially neutralizes SARS-CoV-2 infection. In addition, it stimulates cellular responses against all variants of concern.


Assuntos
Anticorpos Antivirais/sangue , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos T/imunologia , Vacinas de Produtos Inativados/imunologia , Adolescente , Adulto , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Neutralizantes/sangue , Humanos , Interferon gama/imunologia , Pessoa de Meia-Idade , Testes de Neutralização , SARS-CoV-2/classificação , Vacinação , Adulto Jovem
9.
Front Immunol ; 12: 742914, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34659237

RESUMO

Constant efforts to prevent infections by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are actively carried out around the world. Several vaccines are currently approved for emergency use in the population, while ongoing studies continue to provide information on their safety and effectiveness. CoronaVac is an inactivated SARS-CoV-2 vaccine with a good safety and immunogenicity profile as seen in phase 1, 2, and 3 clinical trials around the world, with an effectiveness of 65.9% for symptomatic cases. Although vaccination reduces the risk of disease, infections can still occur during or after completion of the vaccination schedule (breakthrough cases). This report describes the clinical and immunological profile of vaccine breakthrough cases reported in a clinical trial in progress in Chile that is evaluating the safety, immunogenicity, and efficacy of two vaccination schedules of CoronaVac (clinicaltrials.gov NCT04651790). Out of the 2,263 fully vaccinated subjects, at end of June 2021, 45 have reported symptomatic SARS-CoV-2 infection 14 or more days after the second dose (1.99% of fully vaccinated subjects). Of the 45 breakthrough cases, 96% developed mild disease; one case developed a moderate disease; and one developed a severe disease and required mechanical ventilation. Both cases that developed moderate and severe disease were adults over 60 years old and presented comorbidities. The immune response before and after SARS-CoV-2 infection was analyzed in nine vaccine breakthrough cases, revealing that six of them exhibited circulating anti-S1-RBD IgG antibodies with neutralizing capacities after immunization, which showed a significant increase 2 and 4 weeks after symptoms onset. Two cases exhibited low circulating anti-S1-RBD IgG and almost non-existing neutralizing capacity after either vaccination or infection, although they developed a mild disease. An increase in the number of interferon-γ-secreting T cells specific for SARS-CoV-2 was detected 2 weeks after the second dose in seven cases and after symptoms onset. In conclusion, breakthrough cases were mostly mild and did not necessarily correlate with a lack of vaccine-induced immunity, suggesting that other factors, to be defined in future studies, could lead to symptomatic infection after vaccination with CoronaVac.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Linfócitos T/imunologia , Vacinas de Produtos Inativados/imunologia , Adulto , Idoso , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/patologia , Chile , Comorbidade , Feminino , Humanos , Esquemas de Imunização , Imunogenicidade da Vacina/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Interferon gama/imunologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Vacinação , Adulto Jovem
10.
medRxiv ; 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35441164

RESUMO

Background: The ongoing COVID-19 pandemic has had a significant impact worldwide, with an incommensurable social and economic burden. The rapid development of safe and protective vaccines against this disease is a global priority. CoronaVac is a vaccine prototype based on inactivated SARS-CoV-2, which has shown promising safety and immunogenicity profiles in pre-clinical studies and phase 1/2 trials in China. To this day, four phase 3 clinical trials are ongoing with CoronaVac in Brazil, Indonesia, Turkey, and Chile. This article reports the safety and immunogenicity results obtained in a subgroup of participants aged 18 years and older enrolled in the phase 3 Clinical Trial held in Chile. Methods: This is a multicenter phase 3 clinical trial. Healthcare workers aged 18 years and older were randomly assigned to receive two doses of CoronaVac or placebo separated by two weeks (0-14). We report preliminary safety results obtained for a subset of 434 participants, and antibody and cell-mediated immunity results obtained in a subset of participants assigned to the immunogenicity arm. The primary and secondary aims of the study include the evaluation of safety parameters and immunogenicity against SARS-CoV-2 after immunization, respectively. This trial is registered at clinicaltrials.gov ( NCT04651790 ). Findings: The recruitment of participants occurred between November 27 th , 2020, until January 9 th , 2021. 434 participants were enrolled, 397 were 18-59 years old, and 37 were ≥60 years old. Of these, 270 were immunized with CoronaVac, and the remaining 164 participants were inoculated with the corresponding placebo. The primary adverse reaction was pain at the injection site, with a higher incidence in the vaccine arm (55.6%) than in the placebo arm (40.0%). Moreover, the incidence of pain at the injection site in the 18-59 years old group was 58.4% as compared to 32.0% in the ≥60 years old group. The seroconversion rate for specific anti-S1-RBD IgG was 47.8% for the 18-59 years old group 14 days post immunization (p.i.) and 95.6% 28 and 42 days p.i. For the ≥60 years old group, the seroconversion rate was 18.1%, 100%, and 87.5% at 14, 28, and 42 days p.i., respectively. Importantly, we observed a 95.7% seroconversion rate in neutralizing antibodies for the 18-59 years old group 28 and 42 days p.i. The ≥60 years old group exhibited seroconversion rates of 90.0% and 100% at 28 and 42 days p.i. Interestingly, we did not observe a significant seroconversion rate of anti-N-SARS-CoV-2 IgG for the 18-59 years old group. For the participants ≥60 years old, a modest rate of seroconversion at 42 days p.i. was observed (37.5%). We observed a significant induction of a T cell response characterized by the secretion of IFN-γ upon stimulation with Mega Pools of peptides derived from SARS-CoV-2 proteins. No significant differences between the two age groups were observed for cell-mediated immunity. Interpretation: Immunization with CoronaVac in a 0-14 schedule in adults of 18 years and older in the Chilean population is safe and induces specific IgG production against the S1-RBD with neutralizing capacity, as well as the activation of T cells secreting IFN-γ, upon recognition of SARS-CoV-2 antigens. Funding: Ministry of Health of the Chilean Government; Confederation of Production and Commerce, Chile; Consortium of Universities for Vaccines and Therapies against COVID-19, Chile; Millennium Institute on Immunology and Immunotherapy.

11.
Vaccine ; 38(34): 5418-5423, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32600908

RESUMO

The World Health Organization declared the COVID-19 disease as a pandemic requiring a rapid response. Through online search, direct communication with network members and an internal survey, engagements of developing countries' vaccine manufacturers' network members in the research and development of COVID-19 vaccines and their capacities in the manufacturing, fill-finish and distribution of vaccines were assessed. Currently, 19 network members engaged in research and development of COVID-19 vaccines, using six principal technology platforms. In addition, an internal survey showed that the number of vaccines supplied collectively by 37 members, in 2018-19, was about 3.5 billion doses annually. Almost a third of network members having vaccines prequalified by the World Health Organization comply with international regulations and mechanisms to distribute vaccines across borders. The use of existing manufacturing, fill-finish and distribution capabilities can support an efficient roll-out of vaccines against COVID-19, while maintaining supply security of existing vaccines for on-going immunization programmes.


Assuntos
Pesquisa Biomédica/organização & administração , Infecções por Coronavirus , Indústria Farmacêutica/organização & administração , Cooperação Internacional , Pandemias , Pneumonia Viral , Vacinas Virais/provisão & distribuição , COVID-19 , Vacinas contra COVID-19 , Ensaios Clínicos como Assunto , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Humanos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/imunologia , Organização Mundial da Saúde
12.
J Mol Biol ; 383(4): 772-82, 2008 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-18708071

RESUMO

The asymmetric distribution of the nucleotide-bound state of Ran across the nuclear envelope is crucial for determining the directionality of nuclear transport. In the nucleus, Ran is primarily in the guanosine 5'-triphosphate (GTP)-bound state, whereas in the cytoplasm, Ran is primarily guanosine 5'-diphosphate (GDP)-bound. Conformational changes within the Ran switch I and switch II loops are thought to modulate its affinity for importin-beta. Here, we show that RanGDP and importin-beta form a stable complex with a micromolar dissociation constant. This complex can be dissociated by importin-beta binding partners such as importin-alpha. Surprisingly, the crystal structure of the Kap95p-RanGDP complex shows that Kap95p induces the switch I and II regions of RanGDP to adopt a conformation that resembles that of the GTP-bound form. The structure of the complex provides insights into the structural basis for the gradation of affinities regulating nuclear protein transport.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Guanosina Difosfato/metabolismo , Conformação Proteica , beta Carioferinas/química , beta Carioferinas/metabolismo , Proteína ran de Ligação ao GTP/química , Proteína ran de Ligação ao GTP/metabolismo , Sequência de Aminoácidos , Cristalografia por Raios X , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Complexos Multiproteicos/química , Complexos Multiproteicos/metabolismo , Ligação Proteica , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência , beta Carioferinas/genética , Proteína ran de Ligação ao GTP/genética
13.
Methods Mol Biol ; 426: 577-87, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18542891

RESUMO

This chapter describes the methodology adopted in a project aimed at structural and functional characterization of proteins that potentially play an important role in mammalian macrophages. The methodology that underpins this project is applicable to both small research groups and larger structural genomics consortia. Gene products with putative roles in macrophage function are identified using gene expression information obtained via DNA microarray technology. Specific targets for structural and functional characterization are then selected based on a set of criteria aimed at maximizing insight into function. The target proteins are cloned using a modification of Gateway cloning technology, expressed with hexa-histidine tags in E. coli, and purified to homogeneity using a combination of affinity and size exclusion chromatography. Purified proteins are finally subjected to crystallization trials and/or NMR-based screening to identify candidates for structure determination. Where crystallography and NMR approaches are unsuccessful, chemical cross-linking is employed to obtain structural information. This resulting structural information is used to guide cell biology experiments to further investigate the cellular and molecular function of the targets in macrophage biology. Jointly, the data sheds light on the molecular and cellular functions of macrophage proteins.


Assuntos
Macrófagos/metabolismo , Proteínas/química , Proteômica/métodos , Proteômica/organização & administração , Animais , Artrite/genética , Artrite/metabolismo , Biologia Computacional , Cristalografia por Raios X , Humanos , Camundongos , Conformação Proteica , Dobramento de Proteína , Proteínas/genética , Proteínas/isolamento & purificação , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/metabolismo , Queensland , Universidades
14.
Proc Natl Acad Sci U S A ; 104(25): 10382-7, 2007 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-17563367

RESUMO

Acyl-CoA thioesterases (Acots) catalyze the hydrolysis of fatty acyl-CoA to free fatty acid and CoA and thereby regulate lipid metabolism and cellular signaling. We present a comprehensive structural and functional characterization of mouse acyl-CoA thioesterase 7 (Acot7). Whereas prokaryotic homologues possess a single thioesterase domain, mammalian Acot7 contains a pair of domains in tandem. We determined the crystal structures of both the N- and C-terminal domains of the mouse enzyme, and inferred the structure of the full-length enzyme using a combination of chemical cross-linking, mass spectrometry, and molecular modeling. The quaternary arrangement in Acot7 features a trimer of hotdog fold dimers. Both domains of Acot7 are required for activity, but only one of two possible active sites in the dimer is functional. Asn-24 and Asp-213 (from N- and C-domains, respectively) were identified as the catalytic residues through site-directed mutagenesis. An enzyme with higher activity than wild-type Acot7 was obtained by mutating the residues in the nonfunctional active site. Recombinant Acot7 was shown to have the highest activity toward arachidonoyl-CoA, suggesting a function in eicosanoid metabolism. In line with the proposal, Acot7 was shown to be highly expressed in macrophages and up-regulated by lipopolysaccharide. Overexpression of Acot7 in a macrophage cell line modified the production of prostaglandins D2 and E2. Together, the results link the molecular and cellular functions of Acot7 and identify the enzyme as a candidate drug target in inflammatory disease.


Assuntos
Inflamação , Palmitoil-CoA Hidrolase/química , Palmitoil-CoA Hidrolase/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Cristalografia por Raios X , Dimerização , Corantes Fluorescentes , Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Indóis , Lipopolissacarídeos/farmacologia , Macrófagos/enzimologia , Macrófagos/metabolismo , Espectrometria de Massas , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Palmitoil-CoA Hidrolase/análise , Palmitoil-CoA Hidrolase/genética , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Regulação para Cima/efeitos dos fármacos
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