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1.
J Pediatr ; 262: 113643, 2023 11.
Article in English | MEDLINE | ID: mdl-37517652

ABSTRACT

We assessed the safety of hexavalent vaccine diphtheria and tetanus toxoids and acellular pertussis, inactivated poliovirus, hepatitis b, and haemophilus influenzae b conjugate vaccine in the Vaccine Adverse Event Reporting System. Five hundred-one reports of adverse events (AEs) were identified; 21 (4.2%) were serious. Most frequently reported AEs were fever (10.2%) and injection site erythema (5.4%). AEs reported were consistent with findings from prelicensure studies.


Subject(s)
Diphtheria-Tetanus-Pertussis Vaccine , Haemophilus Vaccines , Humans , Diphtheria-Tetanus-Pertussis Vaccine/adverse effects , Haemophilus Vaccines/adverse effects , Hepatitis B Vaccines/adverse effects , Poliovirus Vaccine, Inactivated/adverse effects , Vaccines, Combined/adverse effects , Vaccines, Conjugate
2.
Stat Med ; 42(18): 3283-3301, 2023 08 15.
Article in English | MEDLINE | ID: mdl-37221996

ABSTRACT

In the postmarket drug and vaccine safety surveillance, when the number of adverse events follows a Poisson distribution, the ratio between the exposed and the unexposed person-time information is the random variable that governs the decision rule about the safety of the drug or vaccine. The probability distribution function of such a ratio is derived in this paper. Exact point and interval estimators for the relative risk are discussed as well as statistical hypothesis testing. To the best of our knowledge, this is the first paper that provides an unbiased estimator for the relative risk based on the person-time ratio. The applicability of this new distribution is illustrated through a real data analysis aimed to detect increased risk of occurrence of Myocarditis/Pericarditis following mRNA COVID-19 vaccination in Manitoba, Canada.


Subject(s)
COVID-19 , Vaccines , Humans , Adverse Drug Reaction Reporting Systems , COVID-19 Vaccines , COVID-19/epidemiology , COVID-19/prevention & control , Vaccines/adverse effects , Likelihood Functions , Vaccination , Poisson Distribution
3.
Vaccine ; 40(47): 6722-6729, 2022 11 08.
Article in English | MEDLINE | ID: mdl-36055876

ABSTRACT

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


Subject(s)
COVID-19 Vaccines , COVID-19 , Humans , Brazil/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Immunization Programs , Pandemics/prevention & control , Vaccination/adverse effects , Vaccines/adverse effects
4.
J Clin Immunol ; 42(8): 1593-1599, 2022 11.
Article in English | MEDLINE | ID: mdl-35976470

ABSTRACT

BACKGROUND: Information on anaphylaxis among recipients of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains scarce. OBJECTIVE: To identify the observed incidence of anaphylaxis in recipients of different anti-SARS-CoV-2 vaccines. METHODS: A nationwide observational study among recipients of 61,414,803 doses of seven different anti-SARS-CoV-2 vaccines, describing the incidence and characteristics of adult patients (age ≥ 18 years) who developed anaphylaxis as an adverse event following immunization (AEFI) against SARS-CoV-2 vaccines between December 24, 2020, and October 15, 2021, in Mexico. RESULTS: Sixty-six patients developed anaphylaxis as an AEFI, for an overall observed incidence of 1.07 cases per 1,000,000 (95% CI 0.84-1.37) administered doses. Eighty-six percent of the patients were female, consistent with previous reports of AEFI to COVID-19 vaccines. mRNA-based vaccine recipients had the highest frequency of anaphylaxis, followed by adenovirus-vectored vaccines and inactivated virus recipients, with an observed incidence of 2.5, 0.7, and 0.2 cases per 1,000,000 doses administered, respectively. Only 46% of the patients received correct treatment with epinephrine as the first-line treatment through the appropriate route and dose. We detected one case of anaphylactic reaction-related death occurring 5 min following immunization with ChAdOx1 nCov-19 for a mortality rate of 1.5% among those who developed this AEFI. CONCLUSIONS: In our population, anaphylactic reactions were infrequent. Our study provides further evidence supporting the security of these newly developed vaccines.


Subject(s)
Anaphylaxis , COVID-19 Vaccines , COVID-19 , Adolescent , Adult , Female , Humans , Male , Anaphylaxis/chemically induced , Anaphylaxis/epidemiology , ChAdOx1 nCoV-19/adverse effects , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , SARS-CoV-2 , Mexico/epidemiology
5.
J Pediatr ; 250: 45-53.e3, 2022 11.
Article in English | MEDLINE | ID: mdl-35948192

ABSTRACT

OBJECTIVES: To estimate the risk of recurrence of adverse events following immunization (AEFIs) upon revaccination and to determine among patients with suspected vaccine allergy whether allergy skin test positivity was associated with AEFI recurrence. STUDY DESIGN: This prospective observational study included patients assessed in the Canadian Special Immunization Clinic Network from 2013 to 2019 with AEFIs who required revaccination with the vaccine temporally associated with their AEFI. Participants underwent standardized assessment and data collection. Special Immunization Clinic physicians used guidelines to inform their recommendations. Participants were followed up after revaccination to capture AEFI recurrences. Data were transferred to a central database for descriptive analysis. RESULTS: Overall, 588 participants were assessed for 627 AEFIs; 570 (91%) AEFIs occurred in children <18 years of age. AEFIs included immediate hypersensitivity (130/627; 21%), large local reactions (110/627; 18%), nonurticarial rash (51/627; 8%), seizures (26/627; 4%), and thrombocytopenia (11/627; 2%). Revaccination was recommended to 513 of 588 (87%) participants. Among participants recommended and due for revaccination during the study period, 63% (299/477) were revaccinated. AEFI recurrence was 10% (31/299) overall, 31% (15/49) for large local reactions, and 7% (5/66) for immediate hypersensitivity. No recurrence was serious. Among 92 participants with suspected vaccine allergy who underwent skin testing and were revaccinated, the negative predictive value of skin testing for AEFI recurrence was 96% (95% CI 92.5%-99.5%). CONCLUSIONS: Most individuals with AEFIs were safely revaccinated. Among those with suspected vaccine allergy, skin testing may help determine the safety of revaccination.


Subject(s)
Hypersensitivity, Immediate , Hypersensitivity , Immunization, Secondary , Immunization , Vaccines , Child , Humans , Adverse Drug Reaction Reporting Systems , Canada , Hypersensitivity/etiology , Hypersensitivity, Immediate/chemically induced , Immunization/adverse effects , Immunization, Secondary/adverse effects , Vaccination/adverse effects , Vaccines/adverse effects
6.
Front Public Health ; 10: 907652, 2022.
Article in English | MEDLINE | ID: mdl-35692333

ABSTRACT

Reports of side effects of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasing worldwide. Capillary leak syndrome and vaccine-induced immune thrombotic thrombocytopenia are very rare but life-threatening adverse events that should be identified early and treated. However, isolated thrombocytopenia can indicate pseudothrombocytopenia. In certain people, ethylenediaminetetraacetic acid (EDTA) induces an in vitro platelet aggregation, resulting in misleading underestimation of platelet counts. It is essential to recognize pseudothrombocytopenia to prevent diagnostic errors, overtreatment, anxiety, and unnecessary invasive procedures. We present a case who developed generalized edema and persistent pseudothrombocytopenia after the first dose of the ChAdOx1 nCoV-19 vaccine (AstraZeneca).


Subject(s)
COVID-19 , Thrombocytopenia , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , ChAdOx1 nCoV-19 , Edema , Humans , SARS-CoV-2 , Thrombocytopenia/chemically induced , Thrombocytopenia/diagnosis , Vaccination/adverse effects
7.
Vaccines (Basel) ; 10(3)2022 Mar 18.
Article in English | MEDLINE | ID: mdl-35335098

ABSTRACT

Vaccine hesitancy due to safety concerns is a hindrance to the success of vaccination campaigns. In February 2021, Trinidad and Tobago commenced its National COVID-19 Vaccination Program. Healthcare workers were among the first group to receive the ChAdOx1 nCoV-19 (Oxford−AstraZeneca (Covishield, Serum Institute of India, Pune, India), the first COVID-19 vaccine available nationally. This study examined the safety of this vaccine in terms of the systemic and local adverse events following immunization reported by healthcare worker recipients. A cross-sectional study was conducted via a telephone questionnaire. Data concerning demographics, medical and COVID-19-related anamneses, and local and systemic side effects experienced within the first 48 h after receiving the first and second dose of this vaccine, respectively, were gathered. Among the 687 participants (male = 275; female = 412), prevalence of fever, body pain, chills, nausea, myalgia, headache, malaise, fatigue, and other systemic symptoms declined significantly 48 h after administration of the second dose compared to the first dose. Chi-square test and multiple logistic regression demonstrated the greater likelihood of younger recipients to report systemic symptoms compared to older recipients. Multiple logistic regression indicated that females were more likely to report headache, fatigue, and discomfort, and were less likely to report no symptoms, compared to males, after both doses. On average, recipients reported less local and systemic side effects 48 h after receiving the second dose compared to the first dose. The reported rate of occurrence of side effects was <50% for most adverse events, which is consistent with the manufacturer's claims that the vaccine is safe. This study adds data on the safety of this vaccine in a population that has not been previously studied. The findings can inform public health policy efforts to lower vaccine hesitancy based on safety concerns surrounding the ChAdOx1 nCoV-19 vaccine across various groups in society, including healthcare workers.

8.
Hum Vaccin Immunother ; 17(11): 4225-4234, 2021 11 02.
Article in English | MEDLINE | ID: mdl-34495813

ABSTRACT

OBJECTIVES: To describe the trend in the frequency of adverse events (AE) records associated to pertussis component vaccines between January 1st, 2015 and June 30th, 2020 in infants younger than 2-years-old in Chile, by reviewing the records submitted to the AEFI NIP, stratified by DTP-vaccine type, wP or aP. MATERIALS AND METHODS: This was a retrospective observational study including all AEFI records of DTP (either aP or wP)-containing vaccines in the described sample. A descriptive analysis was performed according to vaccine type and AEFI, using MedDRA terminology. RESULTS: The total number of AEFI reports was 1,697: 815 corresponding to wP vaccines, 417 to aP vaccines, and 465 with unknown type. The reporting rates for the years 2015 to 2020 were 40.1, 56.2, 37.1, 24.7, 19.1, and 12.2 per 100,000 doses administered, respectively. The most reported AEFI were injection site erythema (42.9%), pyrexia (35.7%), and pain at the injection site (29.2%). Among all cases, 5.8% were SAEs (n = 98), 5.9% were SAEs for wP vaccines (n = 48) and 5.3% were for aP vaccines (n = 22). DISCUSSION: A significant decrease in AEFI reports was observed as of 2018, the year that the DTaP-IPV-HepB-Hib was introduced in the NIP.


Subject(s)
Diphtheria-Tetanus-Pertussis Vaccine , Diphtheria-Tetanus-acellular Pertussis Vaccines , Child, Preschool , Chile/epidemiology , Diphtheria-Tetanus-Pertussis Vaccine/adverse effects , Diphtheria-Tetanus-acellular Pertussis Vaccines/adverse effects , Humans , Infant , Pertussis Vaccine/adverse effects , Retrospective Studies , Vaccines, Combined
9.
Clin Immunol ; 230: 108818, 2021 09.
Article in English | MEDLINE | ID: mdl-34358692

ABSTRACT

Vaccines are the most effective strategy to mitigate the global impact of COVID-19. However, vaccine hesitancy is common, particularly among minorities. Guillain-Barré syndrome (GBS) is the most common autoimmune illness of the peripheral nervous system, occurring at an incidence of 1.1/100,000 worldwide. A causal link between mRNA vaccines and GBS has not been previously evaluated. We analyzed a cohort of 3,890,250 Hispanic/Latinx recipients of the BNT162b2 mRNA vaccine (613,780 of whom had already received both doses) for incident GBS occurring within 30 days from vaccine administration. Seven cases of GBS were detected among first-dose recipients, for an observed incidence of 0.18/100,000 administered doses during the prespecified timeframe of 30 days. No cases were reported after second-dose administration. Our data suggest that, among recipients of the BNT162b2 mRNA vaccine, GBS may occur at the expected community-based rate; however, this should be taken with caution as the current incidence of GBS among the unvaccinated population against COVID-19 is still undetermined. We hope that this preliminary data will increase the public perception of safety toward mRNA-based vaccines and reduce vaccine hesitancy.


Subject(s)
COVID-19 Vaccines/adverse effects , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Guillain-Barre Syndrome/etiology , SARS-CoV-2 , Cohort Studies , Humans , Retrospective Studies
10.
Vaccine ; 39(34): 4849-4855, 2021 08 09.
Article in English | MEDLINE | ID: mdl-34275672

ABSTRACT

Detection and surveillance of vaccine safety hazards is a public health staple. In the post-marketing phase, when vaccines are used in mass, it is crucial to monitor potential signals of adverse reactions that may have been missed in the pre-marketing phase. We analysed spontaneous reports of drug adverse events in El Salvador to assess a potential safety signal related to an increase in febrile seizures following the pentavalent (diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenzae Type B) vaccine in 2019. This was a retrospective observational study of adverse event notifications in the national electronic drug safety database from 2011 to 2019. We performed standard disproportionality analysis computing Proportional Reporting Risk (PRR), Reporting Odds Ratio (ROR), Relative Reporting Ratio (RRR), Chi-squared, and Information Component (IC), comparing the pairing of febrile seizures and pentavalent vaccine to all other drugs and adverse events recorded in 2019. The occurrence of febrile seizures following pentavalent vaccination exceeded the WHO expected rate of six cases × 100 000 doses administered from April 2019, with a maximum of 9.2 in September. IC was 4.3, ORR 421.9 (95% Confidence Interval, CI: 123.8-1437.7), PRR 223.5 (95 %CI: 70.2-710.9), RRR was 19.5. The first booster presented the highest rate (14.6 per 100,000 doses) of febrile seizures, more than double than expected. Rates for 2018 remained below expected. Reports of febrile seizures following pentavalent vaccine were also on the increase globally since 2014, with highest rates in 2018 and 2019. There was a disproportion of febrile seizures notifications following pentavalent in El Salvador in 2019, suggesting the existence of a safety signal. This may be due to the change in provider. Further studies should assess the causes of the increase and compute costs and benefits of this vaccination to determine if switching to a less reactogenic vaccine formulation is indicated.


Subject(s)
Haemophilus Vaccines , Pharmaceutical Preparations , Diphtheria-Tetanus-Pertussis Vaccine/adverse effects , El Salvador , Haemophilus Vaccines/adverse effects , Hepatitis B Vaccines/adverse effects , Humans , Infant , Poliovirus Vaccine, Inactivated , Vaccines, Combined/adverse effects
11.
Virus Res ; 301: 198454, 2021 08.
Article in English | MEDLINE | ID: mdl-34015363

ABSTRACT

COVID-19 pandemic has resulted in millions of deaths and a social-economic crisis. A worldwide effort was made to develop efficient vaccines for this disease. A vaccine should produce immune responses with specific and neutralizing antibodies, and without harmful effects such as the antibody-dependent enhancement that may be associated with severe acute respiratory syndrome. Vaccine design involves the selection of platforms that includes viral, viral-vector, protein, nucleic acid, or trained immunity-based strategies. Its development initiates at a pre-clinical stage, followed by clinical trials when successful. Only if clinical trials show no significant evidence of safety concerns, vaccines can be manufactured, stored, and distributed to immunize the population. So far, regulatory authorities from many countries have approved nine vaccines with phase 3 results. In the current pandemic, a paradigm for the COVID-19 vaccine development has arisen, as many challenges must be overcome. Mass-production and cold-chain storage to immunize large human populations should be feasible and fast, and a combination of different vaccines may boost logistics and immunization. In silico trials is an emerging and innovative field that can be applied to predict and simulate immune, molecular, clinical, and epidemiological outcomes of vaccines to refine, reduce, and partially replace steps in vaccine development. Vaccine-resistant variants of SARS-CoV-2 might emerge, leading to the necessity of updates. A globally fair vaccine distribution system must prevail over vaccine nationalism for the world to return to its pre-pandemic status.


Subject(s)
COVID-19 Vaccines , COVID-19/prevention & control , Pandemics/prevention & control , SARS-CoV-2/immunology , Antibodies, Neutralizing , Antibodies, Viral , Antibody-Dependent Enhancement , COVID-19/virology , Humans
12.
Rev. Méd. Clín. Condes ; 31(3/4): 240-255, mayo.-ago. 2020. ilus, tab
Article in Spanish | LILACS | ID: biblio-1223733

ABSTRACT

La inmunización se encuentra entre las intervenciones en salud pública más exitosas y costo efectivas de todas las épocas, siendo su beneficio tan importante como su seguridad. Las vacunas, como cualquier otro medicamento, pueden generar eventos adversos, los que deben ser monitorizados permanentemente por sistemas de vigilancia. Esta disciplina recibe el nombre de Farmacovigilancia de Vacunas (FVV), encargada de estudiar los Eventos Supuestamente Atribuidos a la Vacunación ó Inmunización (ESAVI). El objetivo de este trabajo es revisar la evolución del sistema de farmacovigilancia de vacunas en Chile. El sistema de FVV chileno se basa en la vigilancia pasiva, y contempla la notificación obligatoria al Instituto de Salud Pública (ISP) de todos los ESAVI detectados, por parte de profesionales de la salud, directores de establecimientos y titulares de registro sanitario, priorizando las notificaciones de ESAVI serios e incluyendo la monitorización de todas las vacunas usadas en el país, tanto las que se encuentran incorporadas al Programa Nacional de Inmunización (PNI), como las que se encuentran fuera de este. El sistema de FVV chileno se caracteriza por un trabajo colaborativo permanente entre el ISP y el PNI, y parte de sus desafíos incluyen generar capacidades y alianzas estratégicas con la academia para la realización de estudios post comercialización sobre seguridad de vacunas. Finalmente, es importante destacar que tanto el marco normativo promulgado el año 2010, como la elaboración de procedimientos, el trabajo permanente con el PNI, y la conformación de un comité de expertos de ESAVI, y las diferentes estrategias de retroalimentación, son medidas implementadas que han contribuido a mejorar la tasa de reporte nacional y el análisis de los casos.


Immunization is among the most successful and cost-effective public health interventions of all times, its benefits being as important as its safety. Vaccines, like any other medicine, can generate adverse events, which must be permanently monitored by surveillance systems. Vaccine Pharmacovigilance (VPV) is the discipline responsible for studying Adverse Events Following Immunization (AEFI). The objective of this article is to review the evolution of the pharmacovigilance system of vaccines in Chile. The Chilean VPV system is based on passive surveillance, and establishes the mandatory reporting of all AEFI detected by healthcare workers, directors of healthcare facilities, and Marketing Authorization holders, to the Public Health Institute of Chile (PHI), prioritizing the reporting of serious ESAVI and including the monitoring of all vaccines used in the country, both those that are incorporated into the National Immunization Program (NIP), and those that are outside of it. The Chilean VPV system is characterized by a permanent collaborative work between the PHI and the NIP, and its challenges include generating capacities and strategic alliances with the academy to carry out post-marketing studies on vaccine safety. Finally, it's important to point out that the regulatory framework promulgated in 2010, as well as the elaboration of procedures, the permanent work with the NIP, the formation of an AEFI expert committee, and the different feedback strategies implemented, have contributed in improving case analysis and the national reporting rate.


Subject(s)
Humans , Vaccines/adverse effects , Immunization/statistics & numerical data , Adverse Drug Reaction Reporting Systems/statistics & numerical data , Drug-Related Side Effects and Adverse Reactions/prevention & control , Pharmacovigilance , Safety , Vaccines/administration & dosage , Chile , Immunization/adverse effects , Immunization Programs
13.
Rev. Méd. Clín. Condes ; 31(3/4): 330-342, mayo.-ago. 2020. ilus, tab
Article in Spanish | LILACS | ID: biblio-1223769

ABSTRACT

El Programa Nacional de Inmunizaciones (PNI) nace el año 1978 en Chile, considerando dentro de sus objetivos la prevención de la morbilidad, discapacidad y muertes secundarias a enfermedades inmunoprevenibles a lo largo de todo el ciclo vital. Dentro de los eventos asociados al proceso de inmunización y que el PNI contempla desde sus inicios, se encuentran los "Errores Programáticos en vacunación" (EPRO), definidos como eventos relacionados con los aspectos operativos de la vacunación, evitables, que no cumplen con las normas establecidas y que no causaron daño en el paciente. La gestión y prevención de los EPRO son vitales para asegurar la calidad y seguridad en la atención de pacientes durante todo su ciclo vital, debido a que a partir de estos se efectúan medidas correctivas y se puede realizar una evaluación de las razones de su ocurrencia pudiendo así evitar su futura aparición, a través de la elaboración de lineamientos para su prevención. Esta tarea ha sido liderada por los equipos de enfermería desde los inicios del proceso de inmunización en nuestro país y la cual se ha demostrado mediante estrategias como la estandarización de procesos, implementación de pautas de seguridad durante todo el proceso de vacunación, realización de reportes de errores con información detallada y veraz, programas de mejoras continua, evaluación de pautas de calidad de procesos, sistemas de gestión de control de stock, trabajo en equipo y metodologías de comunicación efectivas.


The Expanded Program on Immunization (EPI) in Chile, was born in 1978, considering within its objectives the prevention of morbidity, disability and deaths secondary to immunoprevenible diseases throughout the entire life cycle. Among the risks associated with the immunization process and that the EPI contemplates since its inception, there are the "Programmatic Errors in Vaccination" (EPRO), defined as attitudes or procedures that do not comply with the established norms of vaccination and that alone or in together they can generate serious and fatal adverse events. The management and prevention of events such as EPROs are vital for the assurance of quality and safety in patient care throughout their life cycle, a task that the Nursing team has been responsible for leading since the beginning of the immunization process in our country and which has been demonstrated through strategies such as process standardization, implementation of safety guidelines throughout the vaccination process, reporting of errors with detailed and truthful information, continuous improvement programs, evaluation of quality guidelines of processes, stock control management systems, teamwork and effective communication methodologies.


Subject(s)
Humans , Vaccination/adverse effects , Immunization Programs/organization & administration , Medical Errors/prevention & control , Nursing Care/organization & administration , Quality of Health Care , Safety , Immunization/adverse effects , Evidence-Based Nursing , Medication Errors/prevention & control
14.
Stat Med ; 38(12): 2126-2138, 2019 05 30.
Article in English | MEDLINE | ID: mdl-30689224

ABSTRACT

Sequential analysis hypothesis testing is now an important tool for postmarket drug and vaccine safety surveillance. When the number of adverse events accruing in time is assumed to follow a Poisson distribution, and if the baseline Poisson rate is assessed only with uncertainty, the conditional maximized sequential probability ratio test, CMaxSPRT, is a formal solution. CMaxSPRT is based on comparing monitored data with historical matched data, and it was primarily developed under a flat signaling threshold. This paper demonstrates that CMaxSPRT can be performed under nonflat thresholds too. We pose the discussion in the light of the alpha spending approach. In addition, we offer a rule of thumb for establishing the best shape of the signaling threshold in the sense of minimizing expected time to signal and expected sample size. An example involving surveillance for adverse events after influenza vaccination is used to illustrate the method.


Subject(s)
Clinical Trials as Topic/methods , Poisson Distribution , Product Surveillance, Postmarketing/methods , Adverse Drug Reaction Reporting Systems , Computer Simulation , Humans , Influenza Vaccines/adverse effects , Sample Size
15.
Clin Microbiol Infect ; 24(7): 755-763, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29408333

ABSTRACT

OBJECTIVE: Our objective was to describe the risk of hospital admission for virologically confirmed dengue (VCD) and the risk of clinically severe hospitalized VCD occurring up to 4 years after the first dose (years 1 to 4) in three randomized clinical trials comparing tetravalent dengue vaccine with placebo. METHODS: The relative risks (RR) for hospitalized VCD from first dose to year 4 were estimated by year and age-group in individual and combined studies. RESULTS: Overall, from Year 1 to Year 4, 233 and 228 participants had at least one episode of hospitalized VCD in the vaccinated (n = 22 603) and placebo (n = 11 301) groups, respectively (RR = 0.511, 95% CI 0.42-0.62). Among these, 48 and 47 cases, respectively, were classified as clinically severe. In children aged ≥9 years, 88 and 136 participants had at least one episode of hospitalized VCD in the vaccinated (n = 17 629) and placebo (n = 8821) groups, respectively (RR = 0.324; 95% CI 0.24-0.43). In vaccinated participants aged <9 years, particularly in those aged 2-5 years, there were more hospitalized VCD cases compared with the control participants in Year 3 but not in Year 4. The overall RR in those aged <9 years for Year 1 to Year 4 was 0.786 (95% CI 0.60-1.03), with a higher protective effect in the 6-8 year olds than in the 2-5 year olds. CONCLUSIONS: The overall benefit-risk remained positive in those aged ≥9 years up to year 4, although the protective effect was lower in years 3 and 4 than in years 1 and 2.


Subject(s)
Dengue Vaccines/immunology , Dengue Virus/immunology , Dengue/prevention & control , Vaccines, Attenuated/immunology , Adolescent , Antibodies, Viral/blood , Asia/epidemiology , Child , Child, Preschool , Dengue/epidemiology , Female , Follow-Up Studies , Hospitalization/statistics & numerical data , Humans , Latin America/epidemiology , Male , Randomized Controlled Trials as Topic , Risk , Serogroup , Viremia
16.
Rev Inst Med Trop Sao Paulo, v. 60, e37, jul. 2018
Article in English | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-2540

ABSTRACT

Annual vaccination is the most effective way to prevent seasonal influenza illness. Instituto Butantan (IB) performed clinical studies with its 2013, 2014 and 2015 seasonal trivalent influenza vaccines (inactivated split-virion). Prospective cohort studies were carried out to describe the safety and immunogenicity of Instituto Butantan influenza vaccines, in healthy adults and elderly, from 2013 to 2015. Immediately after the informed consent was signed, participants underwent blood collection followed by vaccination. On study days 1, 2 and 3 post-vaccination participants were contacted by the staff to evaluate the occurrence of solicited (local and systemic) and non-solicited adverse reactions. On study day 21 (+7) subjects returned to the clinical site for final safety assessments and blood collection to evaluate post-vaccination immunogenicity. The immunogenicity analyses were performed by means of hemagglutination inhibition (HI) assay. The immunogenicity endpoints were: seroprotection (SPR) and seroconversion (SCR) rates and the geometric mean HI antibody titer ratio (GMTR). The 2013 study was conducted at the Centro de Referência para Imunobiológicos Especiais (CRIE) and at the Centro de Pesquisa Clínica do Instituto da Criança, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo while the 2014 and 2015 studies were conducted at CRIE. The vaccine composition followed the WHO recommendation for the Southern hemisphere seasonal influenza vaccine. Forty-seven healthy adults and 13 elderly participated in the 2013 study, 60 healthy adults and 60 elderly in the 2014 study, and 62 healthy adults and 57 elderly in the 2015 study. In the 2013, 2014 and 2015 studies, pain was the most frequent local adverse reaction and headache the most frequent systemic adverse reaction. All observed adverse reactions were classified as mild or moderate and none as severe. SPR >70% and SPR >60% were observed in adults and elderly, respectively, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. SCR >40% was observed in adults, for the three vaccine viruses, only in the 2014 study and SCR >30% was observed in the elderly, for the three vaccine viruses, only in the 2013 and 2014 studies. GMTR >2.5 among adults, for the three vaccine viruses was only observed in the 2013 study and GMTR >2.0 was observed among elderly, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. The 2013, 2014 and 2015 seasonal influenza vaccines produced by Instituto Butantan were safe and immunogenic according to the immunogenicity criteria defined by the European Medicines Agency (EMA).

17.
Rev. Inst. Nac. Hig ; 49(2): 16-23, 2018. tab, graf
Article in Spanish | LILACS, LIVECS | ID: biblio-1096285

ABSTRACT

El toxoide tetánico es una neurotoxina modificada que induce la formación de una antitoxina protectora contra la enfermedad denominada tétanos. Este antígeno es obtenido a partir de procesos fermentativos con la bacteria anaerobia Clostridium tetani y es utilizado para la formulación de vacunas simples y combinadas inactivadas. Con el propósito de atender a las recomendaciones y regulaciones de la Organización Mundial de la Salud (OMS), el objetivo de este trabajo fue diseñar un Programa de Análisis de Peligros y Puntos Críticos de Control (HACCP) en la producción del antígeno Toxoide Tetánico, desde la recepción de la cepa certificada en el área de producción hasta el almacenamiento del toxoide tetánico purificado. Para ello, inicialmente se evaluó el cumplimiento de los prerequisitos (BPM, POES, BPL). Posteriormente, se procedió al diseño del plan HACCP mediante la ejecución de las 5 tareas preliminares y la aplicación de los 7 principios, conforme a la metodología descrita por la OMS. A partir del análisis de peligros en todas las etapas del proceso de producción del toxoide tetánico se identificaron 3 puntos críticos de control: detoxificación, filtración estéril final y almacenamiento de toxoide tetánico purificado. Se establecieron los límites críticos, los procedimientos de vigilancia, las acciones correctivas, los procedimientos de verificación y de documentación. La propuesta tiene como fin garantizar la calidad e inocuidad del producto elaborado, la protección del personal involucrado en el proceso y del medio ambiente con miras a la obtención de la certificación como laboratorio productor de vacunas


Tetanus toxoid is a modified neurotoxin that induces the formation of protective antitoxin of the disease called tetanus. This antigen is obtained from fermentation processes with anaerobic bacteria Clostridium tetani and it is used to formulate simple and combined inactivated vaccines. In order to meet the recommendations and regulations of World Health Organization (WHO), the aim of this work was to design a Program of Hazard Analysis and Critical Control Points (HACCP) in the production of antigen Tetanus Toxoid, starting from the receipt of the certified strain in the production area through the storage of purified tetanus toxoid. For this, initially fulfilling the prerequisites (GMP, SSOP and GLP) was evaluated. Subsequently, we proceeded to design HACCP plan by running 5 preliminary tasks and application of the 7 principles, according to the methodology described by WHO. From the hazard analysis at all stages of the production process of tetanus toxoid three critical control points were identified: detoxification, final sterile filtration and storage of purified tetanus toxoid. Critical limits, monitoring procedures, corrective actions, verification and documentation procedures were established. The proposal aims to assure the quality and safety of the final product, the protection of personnel involved in the process and the environment, with a view to obtaining certification as a vaccine production laboratory


Subject(s)
Humans , Male , Female , Tetanus , Antitoxins , Tetanus Toxoid , Vaccines , Hazard Analysis and Critical Control Points/methods , Antigens , Public Health , Neurotoxins
18.
Emerg Infect Dis ; 23(11)2017 11.
Article in English | MEDLINE | ID: mdl-28949285

ABSTRACT

The current yellow fever outbreak in Brazil prompted widespread yellow fever virus (YFV) vaccination campaigns, imposing a responsibility to distinguish between vaccine- and wild-type YFV-associated disease. We developed novel multiplex real-time reverse transcription PCRs that differentiate between vaccine and American wild-type YFV. We validated these highly specific and sensitive assays in an outbreak setting.


Subject(s)
Real-Time Polymerase Chain Reaction/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Yellow Fever Vaccine/isolation & purification , Yellow Fever/virology , Yellow fever virus/isolation & purification , Brazil/epidemiology , Disease Outbreaks , Humans , Species Specificity , Yellow Fever/epidemiology
19.
Hum Vaccin Immunother ; 13(8): 1916-1920, 2017 08 03.
Article in English | MEDLINE | ID: mdl-28441094

ABSTRACT

BACKGROUND: Knowledge of background rates of adverse events is crucial to assess vaccine safety concerns. We used data from a rotavirus vaccine study (Ruiz-Palacios et al., NEJM, 2006) including 63,225 infants from 11 Latin American countries to investigate reporting rates of serious adverse events (SAEs) among these infants, and describe rates by country, gender, age, and season. METHODS: For this randomized, double-blind, placebo-controlled, phase 3 trial, investigators from Argentina, Brazil, Chile, Colombia, Dominican Republic, Honduras, Mexico, Nicaragua, Panama, Peru, and Venezuela recruited 6-to-13-week-old healthy infants. The infants received 2 oral doses of vaccine or placebo. The study population was followed 100 d for the assessment of adverse events. SAEs were captured by an active surveillance system. RESULTS: Strong differences in event rates could be observed between countries (min. 48.1/10,000 person-years in Dominican Republic/Peru; max. 296.2/10,000 person-years in Brazil) and between genders: gastroenteritis, pneumonia, bronchiolitis and bronchitis occurred significantly more frequently in males. In addition, infections and infestations, and most disorders, including immune system and cardiac disorders, were more frequent at earlier ages. Finally, looking at seasonality we noted higher rates of SAEs in the second half of the year in all countries except Mexico. DISCUSSION: Significant differences in reporting rates of SAEs between countries, gender and calendar months illustrate the importance of knowing the local epidemiology when interpreting SAEs. Data from clinical trials can be used to better understand background rates of diseases that may be perceived as potential adverse events following immunization.


Subject(s)
Adverse Drug Reaction Reporting Systems , Rotavirus Infections/prevention & control , Rotavirus Vaccines/adverse effects , Brazil/epidemiology , Bronchitis/epidemiology , Child , Colombia/epidemiology , Double-Blind Method , Female , Gastroenteritis/epidemiology , Humans , Immunization Schedule , Infant , Internationality , Latin America/epidemiology , Male , Mexico/epidemiology , Pneumonia/epidemiology , Rotavirus Infections/virology , Rotavirus Vaccines/administration & dosage , Seasons , Sex Factors , Vaccination , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/adverse effects , Vaccines, Attenuated/immunology
20.
Patient Educ Couns ; 99(1): 147-53, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26321294

ABSTRACT

OBJECTIVE: A significant number of parents delay or refuse vaccinating their children. Incidental exposure to vaccine information (i.e., scanned information) may be an important contributor to anti-vaccine sentiment. This study examines the association between scanned information, trust in health information sources and vaccine safety concerns among African American, Mexican American, and non-Hispanic White women. METHODS: Women (N=761) in Los Angeles County were sampled via random digit dial and surveyed regarding use of and trust in health information resources and vaccine safety concerns. RESULTS: Analyses indicate that the sources of information associated with vaccine safety concerns varied by ethnicity. Each ethnic group exhibited different patterns of association between trust in health information resources and vaccine safety concerns. CONCLUSIONS: Information scanning is associated with beliefs about vaccine safety, which may lead parents to refuse or delay vaccinating their children. These relationships vary by ethnicity. PRACTICE IMPLICATIONS: These findings help inform practitioners and policy makers about communication factors that influence vaccine safety concerns. Knowing these sources of information will equip practitioners to better identify women who may have been exposed to anti-vaccine messages and counter these beliefs with effective, vaccine-promoting messages via the most relevant information sources.


Subject(s)
Black or African American/psychology , Consumer Health Information , Health Knowledge, Attitudes, Practice/ethnology , Mexican Americans/psychology , Trust , Vaccines/adverse effects , White People/psychology , Female , Humans , Immunization/adverse effects , Los Angeles , Vaccination/adverse effects
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