In
clinical trials
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 (such as novel vaccines, drugs, dietar ...
, 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 verifie ...
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 close e ...
,
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 sy ...
, 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 respon ...
(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
* Analgesic ...
, which is a chemical additive intended for enhancing the recipient's immune response to the antigen
In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain 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 ...
e. 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 event
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 ther ...
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, commonly referred to as NIH (with each letter pronounced individually), is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late ...
(NIH) has provided the following definition of reactogenicity:
See also
* Vaccine hesitancy
Vaccine hesitancy is a delay in acceptance, or refusal, of vaccines despite the availability of vaccine services and supporting evidence. The term covers refusals to vaccinate, delaying vaccines, accepting vaccines but remaining uncertain abou ...
References
External links
The how’s and what’s of vaccine reactogenicity
''Nature
Nature, in the broadest sense, is the physics, physical world or universe. "Nature" can refer to the phenomenon, phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. ...
'' (2019)
{{Vaccines
Vaccination
Food and Drug Administration
Drug safety