Acquired immunity

A type of immunity that creates immunological memory after an initial response to a specific pathogen, and leads to an enhanced response to future encounters with that pathogen. Unlike the innate immune system, which is pre-programmed to react to common broad categories of pathogen, the adaptive immune system is highly specific to each particular pathogen the body has encountered. The adaptive immune system includes both humoral immunity components and cell-mediated immunity components and destroys invading pathogens. Antibodies are a critical part of the adaptive immune system. Adaptive immunity can provide long-lasting protection, sometimes for the person’s entire lifetime.

Acceptance Criteria

Numeric limits, ranges, or other appropriate scales used to determine the acceptability of test results.

Abbreviated New Drug

Products that are not new drugs but require safety and efficacy evaluation according to the regulations on the approval and review of biological products and other items.


The independent, third-party evaluation of a conformity assessment body (such as certification body, inspection body or laboratory) against recognised standards, conveying formal demonstration of its impartiality and competence to carry out specific conformity assessment tasks (such as certification, inspection and testing).

Acellular vaccine

A vaccine containing partial cellular material as opposed to complete cells.


A long-term inflammatory disease of the airways of the lungs caused by exposure to air pollution and allergens. It is characterized by variable and recurring symptoms, reversible airflow obstruction. Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath.

Asymptomatic infection

The presence of infection without symptoms. Also known as inapparent or subclinical infection.

Attenuated vaccine

A vaccine in which a live virus is weakened (attenuated) through chemical or physical processes in order to produce an immune response without the severe effects of the disease. Attenuated vaccines currently licensed in the United States include measles, mumps, rubella, varicella, rotavirus, yellow fever, smallpox, and some formulations of influenza and typhoid vaccines.

Attrition Bias

A type of selection bias due to systematic differences between study groups in the number and the way participants are lost from a study.


A systematic and independent investigation conducted by the sponsor or others to ensure that the clinical trial is conducted in accordance with the protocol, the sponsor’s standard operating procedures, good clinical practice, and applicable regulatory requirements, in order to ensure the reliability of the data collected in the clinical trial.


An act, process, or method of showing something to be real, true, or genuine.

Autism spectrum disorder (ASD)

A developmental disability that can cause significant social, communication, and behavioral challenges. ASD is usually diagnosed between 18 and 30 months of age. At this time, the cause of autism is not known although many experts believe it to be a genetically based disorder that occurs before birth.


The immune system defends the body against infections and certain other diseases.

Automated System

Any computers, software, firmware, HVAC systems, elevators, electrical systems, fire or life safety systems, security systems and any other electrical, mechanized or computerized devices serving the Project.


A state of control attained by using an aseptic work area and performing activities in a manner that precludes microbial contamination of the exposed sterile product

Auxiliary medical products (AMP)

A medicinal product used for the needs of a clinical trial as described in the protocol, but not as an investigational medicinal product.


Medically clean or without infection.

Average Atomic Weight

The weighted average mass of the atoms in a naturally occurring sample of the element.

Aseptic Process Simulation (APS)

A simulation of the entire aseptic manufacturing process in order to verify the capability of the process to ensure product sterility. APS includes all aseptic operations associated with routine manufacturing (for example, equipment assembly, formulation, filling, lyophilization and sealing processes, as necessary).

Aseptic Processing

Handling sterile materials in a controlled environment, in which the air supply, materials, equipment, and personnel are regulated to control microbial and particulate contamination to acceptable levels.


A laboratory test to find and measure the presence and the amount of a particular sample(blood, urine, or any biological material).


The degree to which the occurrence of two variables or events is linked. Association describes a situation where the likelihood of one event occurring is related to the presence of another event or variable. However, an association between two variables does not necessarily imply a cause-and-effect relationship. The term association and relationship are often used interchangeably.


An immediate and severe allergic reaction to a substance such as a food or drug. Symptoms of anaphylaxis include breathing difficulties, loss of consciousness, and a drop in blood pressure. This condition can be fatal and requires immediate medical attention.


Acquired immune deficiency syndrome is a medical condition where the immune system cannot function properly and protect the body from disease. As a result, the body cannot defend itself against infections such as pneumonia. AIDS is caused by the Human Immunodeficiency Virus (HIV). This virus is spread through direct contact with the blood and body fluids of an infected individual. High risk activities include unprotected sexual intercourse and intravenous drug use (sharing needles). There is no cure for AIDS; however, research efforts to develop a vaccine are ongoing.


Foreign substances (e.g., bacteria or viruses) in the body that are capable of causing disease. The presence of antigens in the body triggers an immune response, usually the production of antibodies.


The ability to specifically combine with the final products of the immune response.

Air Handling Unit (AHU)

The mechanical devices required to achieve the objectives of HVAC (Heating, Ventilation, and Air Conditioning), including cooling, heating, dehumidification, humidification, air purification, and other related purposes.

Antigen presenting cell

A type of immune cell that boosts immune responses by showing antigens on its surface to other cells of the immune system.

Air sampling

A process used to determine what airborne contaminants are present in an environment.

Antisense RNA

Single-chain RNA binds to the target RNA in a sequence that is complementary to the RNA sequence at a certain site and inhibits its action.

Active immunity

The production of antibodies against a specific disease by the immune system. Active immunity can be acquired in two ways, either by contracting the disease or through vaccination. Active immunity is usually long-lasting, but individuals may remain susceptible to variants of the etiologic agent or to milder presentation of the disease.

Airborne particle

Sub-micron particle invisible to the naked eye, which includes pathogens, dust, dirt, soot, smoke, and liquid droplets.


Substances used to slow or inhibit the growth of infectious microorganisms.

Active Pharmaceutical Ingredients (API)

Any substance or mixture of substances intended to be used in the manufacture of a pharmaceutical dosage form and that, when so used, becomes an active ingredient of that pharmaceutical dosage form. Such substances are intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease or to affect the structure and function of the body.


Compartment which permits passage between environments of differing atmospheric pressure or composition while minimizing the mixing of environments or change in pressure in the adjoining spaces.


A solution of antibodies against a toxin. Antitoxin can be derived from either human (e.g., tetanus immune globulin) or animal (usually equine) sources (e.g., diphtheria and botulism antitoxin). Antitoxins are used to confer passive immunity and for treatment.

Actual Yield

The amount of product actually obtained from a reaction.

Airtight container

A container that prevents intrusion of foreign solids or liquids in normal handling or storage conditions and prevents loss, deterioration, degradation, or evaporation of the contents of pharmaceuticals.


A medicine capable of destroying or weakening a virus.


Short-term, intense as in a health effect.


Various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling.


The possibility of generalizing and applying the results from a clinical trial.

Ad Hoc Research

Research designed for a specific purpose and specific client, and conducted as a one-off study or programme of studies.

Allocation concealment

Technique of ensuring that implementation of the random allocation sequence occurs without knowledge of which patient will receive which treatment or placebo.

Applicable Regulatory Requirement

The applicable laws, applicable codes and guidelines and the requirements of any regulatory authority which are applicable in regard to clinical trial.

Adaptive clinical trial

Type of clinical trial where the parameters and conduct of the trial for a candidate drug or vaccine may be changed based on an interim analysis.

Alternative Hypothesis

An opposing theory to the null hypothesis, which generally states that there is statistical significance between two variables.


An agent added in vaccine that increases specific immune responses to an antigen.


Changes made to a clinical trial after it has received regulatory approval.


A medical condition characterized by inflammation of the joints, which causes pain and difficulty moving.

Adverse Drug Reaction

An appreciably harmful or unpleasant reaction resulting from an intervention related to the use of a medicinal product.


A chemical substance that is the subject of chemical analysis.

Adverse event

An undesirable medical condition that occurs following vaccination, which might be associated to the vaccine or its components, or which might be pure coincidence.

Animal model

A living, non-human, often genetic-engineered animal used during the research and investigation of human disease, for the purpose of better understanding the disease process without the risk of harming a human.

Advisory Committee on Immunization Practices (ACIP)

A group of medical and public health experts who develop recommendations on the use of vaccines in the U.S. civilian population. The recommendations stand as public health guidance for the safe use of vaccines and related biological products.


Inhibition of or interference with the action of one substance or organism by another.


The state of being closely associated with or connected to an organization, company, etc.


An acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax most commonly occurs in hoofed mammals but can infect humans.


A close similarity between two things, or an attraction or sympathy for someone or something, especially because of shared characteristics.

Additive Effect

The situation when the combining effects of two drugs equal the sum of the effects of the two drugs acting independently.

Affinity maturation

The process by which activated B cells produce antibodies with increased affinity for antigen during the course of an immune response.


A protein found in the blood, produced in response to foreign substances (e.g., bacteria or viruses) invading the body. Antibodies protect the body from disease by binding to invading organisms and destroying them.

Absolute risk

The probability or chance of an event. It is usually used for the number of events (such as a disease) that occurred in a group, divided by the number of people in that group.