Tozinameran (BNT162b2) Vaccine: The Journey from Preclinical Research to Clinical Trials and Authorization.

Vaccination development and production was an essential question for the prevention and global control of COVID-19. The strong support from governing authorities such as Operation Warp Speed and robust funding has led to the development and authorization of the tozinameran (BNT162b2) vaccine. The BNT162b2 vaccine is a lipid nanoparticle-encapsulated mRNA that encodes for SARS-CoV-2 spike protein, the main site for neutralizing antibodies. Once it binds with the host cells, the lipid nanoparticles enable the transfer of the RNA, causing S antigens' expression of the SARS-CoV-2, conferring immunity. The vaccine is administered as a 2-dose regime 21 days apart for individuals 16 years and older. Pfizer-BioNTech's BNT162b2 vaccine was the first candidate to receive FDA-Emergency Use Authorization (EUA) on December 11, 2020. During phase 2/3 clinical trials, 95% efficacy was reported among 37,706 participants over the age of 16 who received the BNT162b2 vaccination; additionally, 52% efficacy was noted 12 days following the administration of the first dose of BNT162b2, reflecting early protection of COVID-19. The BNT162b2 vaccine has exhibited 100% efficacy in clinical trials of adolescents between the ages of 12 and 15. Clinical trials in pregnant women and children under the age of 12 are expected to also exhibit promising results. This review article encompasses tozinameran (BNT162b2) vaccine journey, summarizing the BNT162b1 and BNT162b2 vaccines from preclinical studies, clinical trial phases, dosages, immune response, adverse effects, and FDA-EUA.

A Phase 1 clinical trial of a DNA vaccine for Venezuelan equine encephalitis delivered by intramuscular or intradermal electroporation.

Venezuelan equine encephalitis virus (VEEV), a mosquito-borne alphavirus, causes periodic epizootics in equines and is a recognized biological defense threat for humans. There are currently no FDA-licensed vaccines against VEEV. We developed a candidate DNA vaccine expressing the E3-E2-6K-E1 genes of VEEV (pWRG/VEE) and performed a Phase 1 clinical study to assess the vaccine's safety, reactogenicity, tolerability, and immunogenicity when administered by intramuscular (IM) or intradermal (ID) electroporation (EP) using the Ichor Medical Systems TriGrid™ Delivery System. Subjects in IM-EP groups received 0.5mg (N=8) or 2.0mg (N=9) of pWRG/VEE or a saline placebo (N=4) in a 1.0ml injection. Subjects in ID-EP groups received 0.08mg (N=8) or 0.3mg (N=8) of DNA or a saline placebo (N=4) in a 0.15ml injection. Subjects were monitored for a total period of 360 days. No vaccine- or device-related serious adverse events were reported. Based on the results of a subject questionnaire, the IM- and ID-EP procedures were both considered to be generally acceptable for prophylactic vaccine administration, with the acute tolerability of ID EP delivery judged to be greater than that of IM-EP delivery. All subjects (100%) in the high and low dose IM-EP groups developed detectable VEEV-neutralizing antibodies after two or three administrations of pWRG/VEE, respectively. VEEV-neutralizing antibody responses were detected in seven of eight subjects (87.5%) in the high dose and five of eight subjects (62.5%) in the low dose ID-EP groups after three vaccine administrations. There was a correlation between the DNA dose and the magnitude of the resulting VEEV-neutralizing antibody responses for both IM and ID EP delivery. These results indicate that pWRG/VEE delivered by either IM- or ID-EP is safe, tolerable, and immunogenic in humans at the evaluated dose levels. Clinicaltrials.gov registry number NCT01984983.

Schistosomiasis vaccine candidate Sm14/GLA-SE: Phase 1 safety and immunogenicity clinical trial in healthy, male adults.

DESIGN: Safety and immunogenicity of a recombinant 14kDa, fatty acid-binding protein(FABP) from Schistosoma mansoni (rSm14) were evaluated through an open, non-placebo-controlled, dose-standardized trial, performed at a single research site. The vaccine was formulated with glucopyranosyl lipid A (GLA) adjuvant in an oil-in-water emulsion (SE) and investigated in 20 male volunteers from a non-endemic area for schistosomiasis in the state of Rio de Janeiro, Brazil. Fifty microgram rSm14 with 10 µg GLA-SE (rSm14/GLA-SE)/dose were given intramuscularly three times with 30-day intervals. Participants were assessed clinically, biochemically and immunologically for up to 120 days. METHODS: Participants were screened for inclusion by physical examination, haematology and blood chemistry; then followed to assess adverse events and immunogenicity. Sera were tested for IgG (total and isotypes) and IgE. T cell induction of cytokines IL-2, IL-5, IL-10, IFNγ and TNFα was assessed by Milliplex kit and flow cytometry. RESULTS: The investigational product showed high tolerability; some self-limited, mild adverse events were observed during and after vaccine administration. Significant increases in Sm14-specific total IgG, IgG1 and IgG3 were observed 30 days after the first vaccination with specific IgG2 and IgG4 after 60 days. An increase in IgE antibodies was not observed at any time point. The IgG response was augmented after the second dose and 88% of all vaccinated subjects had developed high anti-Sm14 IgG titres 90 days after the first injection. From day 60 and onwards, there was an increase in CD4(+) T cells producing single cytokines, particularly TNFα and IL-2, with no significant increase of multi-functional TH1 cells. CONCLUSION: Clinical trial data on tolerability and specific immune responses after vaccination of adult, male volunteers in a non-endemic area for schistosomiasis with rSm14/GLA-SE, support this product as a safe, strongly immunogenic vaccine against schistosomiasis paving the way for follow-up Phase 2 trials. Study registration ID: NCT01154049 at http://www.clinicaltrials.gov.

In silico ischaemia-induced reentry at the Purkinje-ventricle interface.

AIMS: This computational modelling work illustrates the influence of hyperkalaemia and electrical uncoupling induced by defined ischaemia on action potential (AP) propagation and the incidence of reentry at the Purkinje-ventricle interface in mammalian hearts. METHODS AND RESULTS: Unidimensional and bidimensional models of the Purkinje-ventricle subsystem, including ischaemic conditions (defined as phase 1B) in the ventricle and an ischaemic border zone, were developed by altering several important electrophysiological parameters of the Luo-Rudy AP model of the ventricular myocyte. Purkinje electrical activity was modelled using the equations of DiFrancesco and Noble. Our study suggests that an extracellular potassium concentration [K(+)]o >14 mM and a slight decrease in intercellular coupling induced by ischaemia in ventricle can cause conduction block from Purkinje to ventricle. Under these conditions, propagation from ventricle to Purkinje is possible. Thus, unidirectional block (UDB) and reentry can result. When conditions of UDB are met, retrograde propagation with a long delay (320 ms) may re-excite Purkinje cells, and give rise to a reentrant pathway. This induced reentry may be the origin of arrhythmias observed in phase 1B ischaemia. CONCLUSION: In a defined setting of ischaemia (phase 1B), a small amount of uncoupling between ventricular cells, as well as between Purkinje and ventricular tissue, may induce UDBs and reentry. Hyperkalaemia is also confirmed to be an important factor in the genesis of reentrant rhythms, since it regulates the range of coupling in which UDBs may be induced.

Hahnemann and the methodology of pathogenetic trials in healthy volunteers: a reappraisal / Hahnemann e a metodologia de ensaios patogenéticos em voluntários saudáveis: uma reavaliação / Hahnemann y la metodología de ensayos patogenéticos en voluntarios sanos: una reevaluación

This article assesses the guidelines and protocols that Hahnemann developed for homeopathic pathogenetic trials (HPTs) - often referred to as proving - and reappraise them in the light of more recent knowledge and protocols for clinical trials involving human subjects. Innovative features and methods introduced by Hahnemann and aimed at reducing bias are noted. A number of features which are now known to lead to bias in trials and which may be included in the reporting of symptoms are discussed in relation to HPTs. These features include: absence of control groups, absence of random allocation, absence of blinding, the inclusion of trivial and pre-existing symptoms, the inclusion of well-known acquaintances as trial participants, and the lack of definition of the healthy state. Advice from experts and papers published in recent decades related to the design of HPTs are discussed. The importance of developing methods to screen participants in HPTs for susceptibility to the tested medicine is discussed. The absence of trials meeting high quality standards in their design is highlighted. The article concludes with a plea for researchers to show the same desire for rigour and innovation that Hahnemann did in the development of HPTs, whilst fully recognising the requirements and protocols necessary for any trial of medicines on human beings, so that, as Hahnemann wanted, only reliable symptoms from HPTs will be admitted in the materia medica and clinical practice.

Este artigo discute as orientações e protocolos desenvolvidos por Hahnemann, para a realização de ensaios homeopáticos patogenésicos e reavalia-os com base no conhecimento e protocolos atuais, usados em pesquisas clínicas envolvendo humanos. Técnicas e métodos inovadores foram introduzidos por Hahnemann objetivando a redução de viéses estatísticos. Alguns aspectos metodológicos que podem induzir viéses em ensaios patogenésicos e que podem levar a inclusão incorreta de sintomas são discutidos. Dentre vários, podemos citar: ausência de grupo controle, ausência de randomização, ausência de protocolo cego, inclusão de sintomas triviais e pré-existentes, inclusão de conhecidos como participantes no estudo e a falta de definição do estado saudável. Recomendações de especialistas e de trabalhos publicados recentemente, relacionados aos ensaios patogenésicos são discutidos. A importância do desenvolvimento de métodos capazes de identificar a susceptibilidade dos participantes, aos medicamentos testados, é discutida. A ausência de ensaios desenhados com alto padrão metodológico é destacada. Este artigo termina com um apelo para que pesquisadores mantenham o mesmo desejo pela inovação e rigor metodológico, como Hahnemann, no desenvolvimento dos ensaios patogenésicos, não obstante atendendo plenamente os protocolos e requerimentos necessários para qualquer ensaio de medicamentos, com humanos, de forma que, como Hahnemann queria, somente sintomas confiáveis possam ser admitidos na matéria medica e na prática clínica.

Este artículo reevalúa las orientaciones y protocolos que Hahnemann formuló para los ensayos patogenéticos homeopáticos (HPTs) a la luz de conocimientos y protocolos recientes para la investigación en seres humanos. Son mencionados algunos aspectos y métodos innovadores formulados por Hahnemann, en particular aquellos destinados a reducir sesgos. Un número de aspectos actualmente conocidos que llevan a sesgos en ensayos y que pueden aparecer en el reporte de síntomas son discutidos en el contexto de los HPTs. Entre estos aspectos se menciona: ausencia de grupos-controle, ausencia de distribución aleatoria, falta de cegamiento, inclusión de síntomas triviales y pre-existentes, inclusión de personas conocidas como participantes del estudio y la falta de definición del concepto de estado de salud. Se discute la opinión de expertos así como la literatura especializada publicada en las últimas décadas sobre el diseño de HPTs. También es abordad la importancia de formular métodos para seleccionar participantes en HPTs en función de su susceptibilidad a la droga estudiada. Es resaltada la falta de estudios de alta calidad metodológica. O artículo concluye con una convocatoria para que los investigadores utilicen el mismo rigor e espíritu innovador que Hahnemann en el desarrollo de HPTs, y que al mismo tiempo reconozcan plenamente los requisitos y protocolos necesarios en cualquier ensayo de drogas en seres humanos de modo a cumplir el desiderátum de Hahnemann: admitir solamente síntomas confiables en la materia médica y la práctica clínica.

Hahnemann and the methodology of pathogenetic trials in healthy volunteers: a reappraisal / Hahnemann e a metodologia de ensaios patogenéticos em voluntários saudáveis: uma reavaliação / Hahnemann y la metodología de ensayos patogenéticos en voluntarios sanos: una reevaluación

This article assesses the guidelines and protocols that Hahnemann developed for homeopathic pathogenetic trials (HPTs) - often referred to as proving - and reappraise them in the light of more recent knowledge and protocols for clinical trials involving human subjects. Innovative features and methods introduced by Hahnemann and aimed at reducing bias are noted. A number of features which are now known to lead to bias in trials and which may be included in the reporting of symptoms are discussed in relation to HPTs. These features include: absence of control groups, absence of random allocation, absence of blinding, the inclusion of trivial and pre-existing symptoms, the inclusion of well-known acquaintances as trial participants, and the lack of definition of the healthy state. Advice from experts and papers published in recent decades related to the design of HPTs are discussed. The importance of developing methods to screen participants in HPTs for susceptibility to the tested medicine is discussed. The absence of trials meeting high quality standards in their design is highlighted. The article concludes with a plea for researchers to show the same desire for rigour and innovation that Hahnemann did in the development of HPTs, whilst fully recognising the requirements and protocols necessary for any trial of medicines on human beings, so that, as Hahnemann wanted, only reliable symptoms from HPTs will be admitted in the materia medica and clinical practice.(AU)

Este artigo discute as orientações e protocolos desenvolvidos por Hahnemann, para a realização de ensaios homeopáticos patogenésicos e reavalia-os com base no conhecimento e protocolos atuais, usados em pesquisas clínicas envolvendo humanos. Técnicas e métodos inovadores foram introduzidos por Hahnemann objetivando a redução de viéses estatísticos. Alguns aspectos metodológicos que podem induzir viéses em ensaios patogenésicos e que podem levar a inclusão incorreta de sintomas são discutidos. Dentre vários, podemos citar: ausência de grupo controle, ausência de randomização, ausência de protocolo cego, inclusão de sintomas triviais e pré-existentes, inclusão de conhecidos como participantes no estudo e a falta de definição do estado saudável. Recomendações de especialistas e de trabalhos publicados recentemente, relacionados aos ensaios patogenésicos são discutidos. A importância do desenvolvimento de métodos capazes de identificar a susceptibilidade dos participantes, aos medicamentos testados, é discutida. A ausência de ensaios desenhados com alto padrão metodológico é destacada. Este artigo termina com um apelo para que pesquisadores mantenham o mesmo desejo pela inovação e rigor metodológico, como Hahnemann, no desenvolvimento dos ensaios patogenésicos, não obstante atendendo plenamente os protocolos e requerimentos necessários para qualquer ensaio de medicamentos, com humanos, de forma que, como Hahnemann queria, somente sintomas confiáveis possam ser admitidos na matéria medica e na prática clínica.(AU)

Este artículo reevalúa las orientaciones y protocolos que Hahnemann formuló para los ensayos patogenéticos homeopáticos (HPTs) a la luz de conocimientos y protocolos recientes para la investigación en seres humanos. Son mencionados algunos aspectos y métodos innovadores formulados por Hahnemann, en particular aquellos destinados a reducir sesgos. Un número de aspectos actualmente conocidos que llevan a sesgos en ensayos y que pueden aparecer en el reporte de síntomas son discutidos en el contexto de los HPTs. Entre estos aspectos se menciona: ausencia de grupos-controle, ausencia de distribución aleatoria, falta de cegamiento, inclusión de síntomas triviales y pre-existentes, inclusión de personas conocidas como participantes del estudio y la falta de definición del concepto de estado de salud. Se discute la opinión de expertos así como la literatura especializada publicada en las últimas décadas sobre el diseño de HPTs. También es abordad la importancia de formular métodos para seleccionar participantes en HPTs en función de su susceptibilidad a la droga estudiada. Es resaltada la falta de estudios de alta calidad metodológica. O artículo concluye con una convocatoria para que los investigadores utilicen el mismo rigor e espíritu innovador que Hahnemann en el desarrollo de HPTs, y que al mismo tiempo reconozcan plenamente los requisitos y protocolos necesarios en cualquier ensayo de drogas en seres humanos de modo a cumplir el desiderátum de Hahnemann: admitir solamente síntomas confiables en la materia médica y la práctica clínica.(AU)