In clinical trials, reactogenicity is the capacity of a vaccine to produce common, "expected" adverse reactions, especially excessive immunological responses and associated signs and symptoms, including fever and sore arm at the injection site. Other manifestations of reactogenicity typically identified in such trials include bruising, redness, induration, and swelling. [1]
The term reactogenicity was coined by the US Food and Drug Administration (FDA). Typically, reactogenicity is observed upon the administration of an adjuvant, which is a chemical additive intended for enhancing the recipient's immune response to the antigen that is present in a vaccine but can also be observed in non-adjuvanted vaccines. Reactogenicity describes the immediate short-term reactions of a system to vaccines and should not be confused with the long-term consequences sequelae. Assessments of reactogenicity are carried out to evaluate the safety and usability of an experimental vaccine (see Investigational New Drug). It is unclear whether a higher degree of reactogenicity to a vaccine correlates with more severe adverse events, which would require hospitalization or are life-threatening. Adverse events have been linked to a higher degree of reactogenicity; however, the links might have been coincidental. After assessing large databases relating to these events for many years, the FDA has not been able to make such a correlation. [1]
The US National Institutes of Health (NIH) has provided the following definition of reactogenicity: [2]
Reactogenicity events are AEs that are common and known to occur for the intervention/investigational product being studied and should be collected in a standard, systematic format using a grading scale based on functional assessment or magnitude of reaction. Provide a definition of expected vs unexpected AEs and local vs systemic events, based on the risk profile of the intervention/investigational product. This information is found on the IB or package insert. Typically, reactogenicity AEs are solicited and collected on memory cards and documented on a reactogenicity CRF. This information comes from the participant who may also have a memory aid to help recollect their symptoms.
The following is an example of a functional scale for assessing reactogenicity or other parameters not specifically listed in the toxicity table:
0 = Absence of the indicated symptom
1 = Mild (awareness of a symptom but the symptom is easily tolerated)
2 = Moderate (discomfort enough to cause interference with usual activity)
3 = Severe (incapacitating; unable to perform usual activities; requires absenteeism or bed rest)
4 = Life-threatening
Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments and known interventions that warrant further study and comparison. Clinical trials generate data on dosage, safety and efficacy. They are conducted only after they have received health authority/ethics committee approval in the country where approval of the therapy is sought. These authorities are responsible for vetting the risk/benefit ratio of the trial—their approval does not mean the therapy is 'safe' or effective, only that the trial may be conducted.
A vaccine trial is a clinical trial that aims at establishing the safety and efficacy of a vaccine prior to it being licensed.
Pharmacovigilance, also known as drug safety, is the pharmaceutical science relating to the "collection, detection, assessment, monitoring, and prevention" of adverse effects with pharmaceutical products. The etymological roots for the word "pharmacovigilance" are: pharmakon and vigilare. As such, pharmacovigilance heavily focuses on adverse drug reactions (ADR), which are defined as any response to a drug which is noxious and unintended, including lack of efficacy. Medication errors such as overdose, and misuse and abuse of a drug as well as drug exposure during pregnancy and breastfeeding, are also of interest, even without an adverse event, because they may result in an adverse drug reaction.
The Food and Drug Administration's (FDA) New Drug Application (NDA) is the vehicle in the United States through which drug sponsors formally propose that the FDA approve a new pharmaceutical for sale and marketing. Some 30% or less of initial drug candidates proceed through the entire multi-year process of drug development, concluding with an approved NDA, if successful.
An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. The term complication is similar to adverse effect, but the latter is typically used in pharmacological contexts, or when the negative effect is expected or common. If the negative effect results from an unsuitable or incorrect dosage or procedure, this is called a medical error and not an adverse effect. Adverse effects are sometimes referred to as "iatrogenic" because they are generated by a physician/treatment. Some adverse effects occur only when starting, increasing or discontinuing a treatment. Adverse effects can also be caused by placebo treatments . Using a drug or other medical intervention which is contraindicated may increase the risk of adverse effects. Adverse effects may cause complications of a disease or procedure and negatively affect its prognosis. They may also lead to non-compliance with a treatment regimen. Adverse effects of medical treatment resulted in 142,000 deaths in 2013 up from 94,000 deaths in 1990 globally.
Clinical monitoring is the oversight and administrative efforts that monitor a participant's health and efficacy of the treatment during a clinical trial. Both independent and government-run grant-funding agencies, such as the National Institutes of Health (NIH) and the World Health Organization (WHO), require data and safety monitoring protocols for Phase I and II clinical trials conforming to their standards.
An adverse event (AE) is any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. An adverse event can therefore be any unfavourable and unintended sign, symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product.
A serious adverse event (SAE) in human drug trials is defined as any untoward medical occurrence that at any dose
A vaccine adverse event (VAE), sometimes referred to as a vaccine injury, is an adverse event caused by vaccination. The World Health Organization (WHO) knows VAEs as Adverse Events Following Immunization (AEFI).
Clinical research is a branch of healthcare science that determines the safety and effectiveness (efficacy) of medications, devices, diagnostic products and treatment regimens intended for human use. These may be used for prevention, treatment, diagnosis or for relieving symptoms of a disease. Clinical research is different from clinical practice. In clinical practice established treatments are used, while in clinical research evidence is collected to establish a treatment.
H5N1 clinical trials are clinical trials concerning H5N1 vaccines, which are intended to provide immunization to influenza A virus subtype H5N1. They are intended to discover pharmacological effects and identify any adverse reactions the vaccines may achieve in humans.
The Common Terminology Criteria for Adverse Events (CTCAE), formerly called the Common Toxicity Criteria, are a set of criteria for the standardized classification of adverse effects of drugs used in cancer therapy. The CTCAE system is a product of the US National Cancer Institute (NCI).
SDTM defines a standard structure for human clinical trial (study) data tabulations and for nonclinical study data tabulations that are to be submitted as part of a product application to a regulatory authority such as the United States Food and Drug Administration (FDA). The Submission Data Standards team of Clinical Data Interchange Standards Consortium (CDISC) defines SDTM.
A glossary of terms used in clinical research.
The following outline is provided as an overview of and topical guide to clinical research:
ClinicalTrials.gov is a registry of clinical trials. It is run by the United States National Library of Medicine (NLM) at the National Institutes of Health, and is the largest clinical trials database, holding registrations from over 329,000 trials from 209 countries.
The phases of clinical research are the stages in which scientists conduct experiments with a health intervention to obtain sufficient evidence for a process considered effective as a medical treatment. For drug development, the clinical phases start with testing for safety in a few human subjects, then expand to many study participants to determine if the treatment is effective. Clinical research is conducted on drug candidates, vaccine candidates, new medical devices, and new diagnostic assays.
Upadacitinib, sold under the brand name Rinvoq, is a Janus kinase (JAK) inhibitor medication for the treatment of moderately to severely active rheumatoid arthritis and psoriatic arthritis in adults where methotrexate did not work well or could not be tolerated. It was approved for medical use in the United States and in the European Union in 2019, and was developed by the biotech company AbbVie. On January 14, 2022 Rinvoq received FDA approval for treating treatment refractory atopic dermatitis.
COVID-19 vaccine clinical research uses clinical research to establish the characteristics of COVID-19 vaccines. These characteristics include efficacy, effectiveness and safety. As of November 2022, 40 vaccines are authorized by at least one national regulatory authority for public use:
