
In
clinical trials
Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...
, reactogenicity is the capacity of a
vaccine
A vaccine is a biological Dosage form, preparation that provides active acquired immunity to a particular infectious disease, infectious or cancer, malignant disease. The safety and effectiveness of vaccines has been widely studied and verifi ...
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
A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur clo ...
,
redness,
induration
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this sys ...
, and
swelling.
[
]
Origin
The term reactogenicity was coined by the US Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...
(FDA). All vaccines can induce reactogenicity, but reactogenicity is more likely in vaccines containing an adjuvant
In pharmacology, an adjuvant is a drug or other substance, or a combination of substances, that is used to increase the efficacy or potency of certain drugs. Specifically, the term can refer to:
* Adjuvant therapy in cancer management
* Anal ...
, which is a chemical additive intended for enhancing the recipient's immune response to the antigen
In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response.
...
that is present in a vaccine. Reactogenicity describes the immediate short-term reactions of a system to vaccines and should not be confused with the long-term consequences sequela
A sequela (, ; usually used in the plural, sequelae ) is a pathological condition resulting from a disease, injury, therapy, or other trauma. Derived from the Latin word meaning "sequel", it is used in the medical field to mean a complication or ...
e. Assessments of reactogenicity are carried out to evaluate the safety and usability of an experimental vaccine (see Investigational New Drug
The United States Food and Drug Administration's Investigational New Drug (IND) program is the means by which a pharmaceutical industry, pharmaceutical company obtains permission to start human clinical trials and to ship an experimental drug inte ...
). It is unclear whether a higher degree of reactogenicity to a vaccine correlates with more severe adverse event
In pharmaceuticals, an adverse event (AE) is any unexpected or harmful medical occurrence that happens to a patient during medical treatment or a clinical trial. Unlike direct side effects, an adverse event does not necessarily mean the medicati ...
s, 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.
Definition
The US National Institutes of Health
The National Institutes of Health (NIH) is the primary agency of the United States government responsible for biomedical and public health research. It was founded in 1887 and is part of the United States Department of Health and Human Service ...
(NIH) has provided the following definition of reactogenicity:
See also
* Vaccine hesitancy
Vaccine hesitancy is a delay in acceptance, or refusal of vaccines despite availability and supporting evidence. The term covers refusals to vaccinate, delaying vaccines, accepting vaccines but remaining uncertain about their use, or using ce ...
References
External links
The how’s and what’s of vaccine reactogenicity
''Nature
Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...
'' (2019)
{{Vaccines
Vaccination
Food and Drug Administration
Drug safety