Glossary

A vaccine that contains cellular material but not complete cells, specifically, antigenic or allergenic parts of cells. (https://www.dictionary.com/browse/acellular-vaccine)

Results when exposure to a disease organism triggers the immune system to produce antibodies to that disease. Active immunity can be acquired through natural immunity or vaccine-induced immunity.

• Natural immunity is acquired from exposure to the disease organism through infection with the actual disease.
• Vaccine-induced immunity is acquired through the introduction of a killed or weakened form of the disease organism through vaccination.

Either way, if an immune person comes into contact with that disease in the future, their immune system will recognize it and immediately produce the antibodies needed to fight it. Active immunity is long-lasting, and sometimes life-long. (https://www.cdc.gov/vaccines/basics/immunity-types.html#cdc_generic_section_1-active-immunity)

Acute pain: characterized by sharpness or severity of sudden onset; acute illness: having a sudden onset, sharp rise, and short course. (https://www.merriam-webster.com/dictionary/acute)

An agent added to some vaccines that enhances the immune system’s response to vaccine antigens. Adjuvants used in vaccines include aluminum salts and, in Canada and the European Union, squalene, which is a fish-oil derived material. (https://historyofvaccines.org/educational-resources/glossary-terms)

AIDS (acquired immunodeficiency syndrome) is the late stage of HIV infection that occurs when the body’s immune system is badly damaged because of the virus. (https://www.hiv.gov/hiv-basics/overview/about-hiv-and-aids/what-are-hiv-and-aids/)

Allergies happen when the immune system reacts to a foreign substance that gets inside the body. These substances are known as allergens. They include pollen, bee venom and pet dander. Allergies also can happen due to certain foods and medicines that don't cause reactions in most people.

The immune system makes protective proteins called antibodies that attack invaders such as germs. But with allergies, the immune system makes antibodies that mark a specific allergen as harmful, even though it isn't. Coming into contact with the allergen causes an immune system reaction that can inflame the skin, sinuses, airways or digestive system.

Allergic reactions vary from person to person. They can range from minor irritation to a life-threatening emergency called anaphylaxis. While most allergies can't be cured, treatments can help relieve your allergy symptoms. (https://www.mayoclinic.org/diseases-conditions/allergies/symptoms-causes/syc-20351497)

Pertaining to or involving the anus and the genitals. (https://www.oed.com/search/dictionary/?scope=Entries&q=anogenital)

A molecule produced by some cells in the body that binds to a specific antigen during an immune response. An antibody can bind to a toxin, a virus or a bacterium, preventing them from doing harm. (https://www.immunizationinfo.org/issues/general/understanding-vaccine-research-terms/)

Any substance (such as an immunogen or a hapten) foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (such as a protein) and that is capable of binding with a product (such as an antibody or T cell) of the immune response. (https://www.merriam-webster.com/dictionary/antigen)

a.(of a drug or therapy) developed to effectively treat an infection caused by a virus.
b. of or relating to a substance used to prevent or treat a viral infection
(https://www.dictionary.com/browse/antiviral)

having or showing no symptoms of disease. (https://dictionary.cambridge.org/dictionary/english/asymptomatic)

The process by which a virus, bacterium, etc., changes under laboratory conditions to become harmless or less virulent. (https://www.dictionary.com/browse/attenuation)

Bacteria are tiny, single-celled living organisms. There are millions of different types of bacteria. Many can be found in and on your body and are beneficial to you. These bacteria make up your microbiome, which keeps your body healthy. Other bacteria can make you sick. Healthcare providers can treat many bacterial infections with antibiotics. (https://my.clevelandclinic.org/health/articles/24494-bacteria)

• Bacille Calmette-Guérin (BCG) is a vaccine for tuberculosis (TB) disease.
• This vaccine is not generally used in the United States.
• The TB vaccine can cause a false positive TB skin test reaction.
• Tell your health care provider if you have received the TB vaccine.

(https://www.cdc.gov/tb/vaccines/?CDC_AAref_Val=https://www.cdc.gov/tb/publications/factsheets/prevention/bcg.htm)

(see Congenital disorders)

A extra small amount of a vaccine that is given to increase the effect of one given earlier, for example to protect you from a disease for longer (https://www.oxfordlearnersdictionaries.com/definition/english/booster)

(see Varicella)

Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus (CHIKV), an RNA virus in the alphavirus genus of the family Togaviridae. The name chikungunya derives from a word in the Kimakonde language, meaning “to become contorted”. (https://www.who.int/news-room/fact-sheets/detail/chikungunya)

Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae. It is most often spread by drinking water or eating food that has been contaminated. Those who do develop symptoms usually have mild to moderate diarrhea, with or without vomiting. (https://travel.gc.ca/travelling/health-safety/diseases)

Chronic diseases are prolonged conditions that generally cannot be prevented by vaccines or cured completely. Many chronic diseases develop slowly over time sometimes because of poor health behaviors such as smoking or inactivity. Diabetes, arthritis, depression, asthma, congestive heart failure are examples of chronic diseases. (https://www2.gnb.ca/content/gnb/en/departments/health/patientinformation/PrimaryHealthCare/What_is_Primary_Health_Care/Chronic_Disease_Prevention_and_Management.html)

Vaccines must be continuously stored in a limited temperature range – from the time they are manufactured until the moment of vaccination. This is because temperatures that are too high or too low can cause the vaccine to lose its potency (its ability to protect against disease). (https://www.unicef.org/supply/what-cold-chain)

Combination vaccines are made so that two or more vaccines that could be given individually can be administered as one injection. They reduce the number of shots needed while protecting against the same number of diseases.

Combination vaccines are safe. Before a new combination vaccine is approved, it must be shown to be as effective as each vaccine given separately. Side effects of combination vaccines are similar to those of the individual vaccines given separately.

Many of the vaccines available in combinations are not available separately. Therefore, if you turn down one component of the vaccine, all other components are also turned down. For example, refusing the measles vaccine means that a child cannot be immunized against rubella and mumps, either, because the measles vaccine in Canada is only available in combination with the mumps and rubella vaccines.

Examples of combination vaccines:

• Diphtheria, tetanus, pertussis, hepatitis B, polio, Haemophilus influenzae type b (DTaP-HB-IPV-Hib) vaccine.
• Measles, mumps, rubella vaccine (MMR) vaccine.

(https://immunizebc.ca/vaccine-safety/multiple-combination-vaccines)

When enough of the community is immunized against a contagious disease, most other members are protected from infection because there’s little opportunity for the disease to spread. (https://newsinhealth.nih.gov/2011/10/community-immunity)

Congenital disorders are also known as congenital abnormalities, congenital malformations or birth defects. They can be defined as structural or functional anomalies (for example, metabolic disorders) that occur during intrauterine life and can be identified prenatally, at birth, or sometimes may only be detected later in infancy, such as hearing defects. Broadly, congenital refers to the existence at or before birth. (https://www.who.int/news-room/fact-sheets/detail/birth-defects)

A conjugate vaccine is a type of subunit vaccine which combines a weak antigen with a strong antigen as a carrier so that the immune system has a stronger response to the weak antigen. (https://en.wikipedia.org/wiki/Conjugate_vaccine)

Sometimes interchanged with pollution, is the existence of live things or substances produced from bacteria, fungi, viruses, animals, and avian antigens that can have various negative impacts on health. (https://www.biologyonline.com/dictionary/contamination)

COVAX is the vaccines pillar of the Access to COVID-19 Tools (ACT) Accelerator. The ACT Accelerator is a ground-breaking global collaboration to accelerate the development, production, and equitable access to COVID-19 tests, treatments, and vaccines. (https://www.who.int/initiatives/act-accelerator/covax)

COVID-19 is a respiratory disease caused by SARS-CoV-2, a coronavirus discovered in 2019. The virus spreads mainly from person to person through respiratory droplets produced when an infected person coughs, sneezes, or talks. Some people who are infected may not have symptoms. (https://www.cdc.gov/covid/about/?CDC_AAref_Val=https://www.cdc.gov/coronavirus/2019-ncov/your-health/about-covid-19.html)

Dengue (break-bone fever) is a viral infection that spreads from mosquitoes to people. It is more common in tropical and subtropical climates. Most people who get dengue won’t have symptoms. But for those that do, the most common symptoms are high fever, headache, body aches, nausea and rash. Most will also get better in 1–2 weeks. Some people develop severe dengue and need care in a hospital. (https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue)

Diphtheria is a contagious disease that is caused by bacteria. Anyone who has not been immunized can get diphtheria.

The symptoms of diphtheria include:

• sore throat
• fever
• difficulty breathing

Diphtheria can be very serious, especially for infants and very young children. It was once one of the most common causes of death in Canadian children under the age of 5.

Fortunately, diphtheria can be prevented through immunization. The diphtheria vaccine is a safe and effective way to protect you and your children. Thanks to immunization, in the last twenty years less than 5 cases of diphtheria are reported each year in Canada. (https://www.canada.ca/en/public-health/services/immunization/vaccine-preventable-diseases/diphtheria.html)

Ebola virus disease (EVD or Ebola) is a rare but severe illness in humans. It is often fatal. People get infected with Ebola by touching:

• infected animals when preparing, cooking or eating them
• body fluids of an infected person such as saliva, urine, faeces or semen
• things that have the body fluids of an infected person like clothes or sheets.

Ebola enters the body through cuts in the skin or when touching one’s eyes, nose or mouth. Early symptoms include fever, fatigue and headache.

Some types of Ebola can be prevented with vaccines and treated with medicines. (https://www.who.int/en/news-room/fact-sheets/detail/ebola-virus-disease)

A measure used to describe how good a vaccine is at preventing disease. (https://www.nytimes.com/interactive/2021/03/03/science/vaccine-efficacy-coronavirus.html)

Encephalitis is a rare, serious condition that causes inflammation in your brain so that it swells. It can occur as a result of an infection or an autoimmune process. Encephalitis can be life-threatening, regardless of the cause, and can cause long-term complications and medical issues. Treatment varies depending on the cause, but most people with encephalitis require hospitalization so they can receive intensive treatment, including life support measures.

Types of encephalitis

Condition types include infectious encephalitis and autoimmune encephalitis. Infective encephalitis includes:

• Viral encephalitis: This is the most common form of encephalitis. You can develop viral encephalitis after having certain infectious diseases or viruses.
• Arbovirus encephalitis: Mosquitos, fleas and ticks can spread infections that can become encephalitis.
• Bacterial or fungal encephalitis: Encephalitis from bacterial or fungal infections is the least common type of the condition.

(https://my.clevelandclinic.org/health/diseases/6058-encephalitis)

Most commonly used to describe a disease that is prevalent in or restricted to a particular location, region, or population. (https://www.dictionary.com/e/epidemic-vs-pandemic/#endemic-meaning)

An epidemic disease is one “affecting many persons at the same time, and spreading from person to person in a locality where the disease is not permanently prevalent.” The World Health Organization (WHO) further specifies epidemic as occurring at the level of a region or community. (https://www.dictionary.com/e/epidemic-vs-pandemic/#epidemic-meaning)

Epstein-Barr virus (EBV), also known as human herpesvirus 4, is a member of the herpes virus family. It is one of the most common human viruses. EBV is found all over the world. Most people get infected with EBV at some point in their lives. EBV spreads most commonly through bodily fluids, primarily saliva. (https://www.cdc.gov/epstein-barr/about/?CDC_AAref_Val=https://www.cdc.gov/epstein-barr/about-ebv.html)

The elimination of a disease from the world. To date, only one human disease—smallpox—has been eradicated. This was accomplished via a combination of surveillance and vaccination programs. (https://historyofvaccines.org/educational-resources/glossary-terms)

A toxin excreted into the surrounding environment by a bacterium. For example, cholera and diphtheria bacteria produce exotoxins. (https://historyofvaccines.org/educational-resources/glossary-terms)

(see Rubella)

Hepatitis is inflammation of the liver. Inflammation is swelling that happens when tissues of the body are injured or infected. It can damage your liver. This swelling and damage can affect how well your liver functions.

Hepatitis can be an acute (short-term) infection or a chronic (long-term) infection. Some types of hepatitis cause only acute infections. Other types can cause both acute and chronic infections. (https://medlineplus.gov/hepatitis.html)

'Herd immunity', also known as 'population immunity', is the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection. WHO supports achieving 'herd immunity' through vaccination, not by allowing a disease to spread through any segment of the population, as this would result in unnecessary cases and deaths. (https://www.who.int/news-room/questions-and-answers/item/herd-immunity-lockdowns-and-covid-19)

Derived from a different species. (https://www.merriam-webster.com/dictionary/heterologous)

Haemophilus influenzae disease is a name for any illness caused by bacteria called H. influenzae. Some of these illnesses, like ear infections, are mild while others, like bloodstream infections, are very serious. In spite of the name, H. influenzae does not cause influenza (the flu). Vaccines can prevent one type of H. influenzae (type b or Hib) disease. (https://www.cdc.gov/hi-disease/index.html)

The Hib vaccine protects against infection from the bacteria Haemophilus influenzae type b (Hib). Hib can cause serious and life-threatening infections, including meningitis, an infection of the lining that covers the brain, and septicemia, an infection of the blood. Despite its name, this disease is not the same as influenza (the flu). (https://immunizebc.ca/vaccines-by-disease/haemophilus-influenzae-type-b-hib)

Derived from or developed in response to organisms of the same species. (https://www.merriam-webster.com/dictionary/homologous)

Human papilloma virus (HPV) is a very common sexually transmitted infection; there are more than 100 types of HPV, and it is estimated to affect more than 70 per cent of sexually active Canadian men and women at some point in their lives. It typically causes no symptoms and resolves without treatment. However, some types can result in anal and genital warts and others can lead to more serious consequences such as cervical, penile and anal cancers. Immunization helps protect against some types of HPV. (https://www.canada.ca/en/public-health/services/infectious-diseases/sexual-health-sexually-transmitted-infections/human-papillomavirus-hpv.html)

‘Hybrid immunity’ is the term for immunity acquired from both prior infection and vaccination. (https://www.gavi.org/vaccineswork/hybrid-immunity-combination-vaccination-and-prior-infection-probably-offers-best?gad_source=1&gclid=EAIaIQobChMI2OW687eZhAMVMQetBh3tiQf9EAAYASAAEgJTCfD_BwE)

A state of being protected against infectious diseases by either specific or non-specific mechanisms (i.e., immunization, previous natural infection, inoculation, or transfer of protective antibodies). (https://www.dictionary.com/browse/immune)

The immune system is made up of a complex network of organs, cells and proteins that fight infection (microbes). (https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/immune-system#immune-system)

The process of protecting a person or animal from an infectious disease by putting a substance into the body that makes it produce antibodies (= proteins in the blood that fight disease):

• mass/routine immunization
• Immunization gives people the ability to resist infection temporarily or permanently.
• With the use of immunizations in babies, the mortality rate has dropped significantly.

(https://dictionary.cambridge.org/dictionary/english/immunization)

Immunogenicity is the ability of a foreign substance to enter a person's body and cause an immune response. (https://study.com/academy/lesson/what-is-immunogenicity-definition-role-in-blood-transfusions.html)

Immunosuppression, also known as immune suppression or immunocompromised, means the immune system isn't working as well as it normally would. This includes any or all of the defenses that make up the immune system - particularly the white cells in the bloodstream, the spleen and the lymph nodes.

When this system is suppressed, ie not working as it should, it leaves people more vulnerable to infection.

Someone who is immunosuppressed is more likely to need antibiotics or hospital admission for a bacterial infection. Most people who are immunosuppressed can't have live vaccines and they may need to take special precautions when traveling.

Immunosuppressed people are also more vulnerable to certain skin cancers. (https://patient.info/allergies-blood-immune/immune-system-diseases/immune-suppression#what-is-immunosuppression)

treatment or prevention of disease (such as an autoimmune disorder, allergy, or cancer) that involves the stimulation, enhancement, suppression, or desensitization of the immune system. (https://www.merriam-webster.com/dictionary/immunotherapy)

An inactivated vaccine uses viruses and bacteria that have been killed through physical or chemical processes, and so cannot cause disease. (https://historyofvaccines.org/vaccines-101/what-do-vaccines-do/different-types-vaccines)

An infection occurs when a microorganism — such as bacteria, fungi, or a virus — enters a person’s body and causes harm. The effects of infections occur due to the immune system’s attempt to get rid of the invading organism. (https://www.medicalnewstoday.com/articles/196271)

The period of time during which an ill person may pass his or her disease to another. (https://immunize.ca/glossary-terms)

Influenza (also known as “flu”) is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness, and at times can lead to death. (https://www.cdc.gov/flu/signs-symptoms/)

the introduction of a pathogen or antigen into a living organism to stimulate the production of antibodies. (https://www.merriam-webster.com/dictionary/inoculation)

Intramuscular injections are used to deliver medication deep into the muscles. This allows the medication to be absorbed into the bloodstream quickly. (https://www.healthline.com/health/intramuscular-injection)

Invasive meningococcal disease is a serious disease caused by infection with the bacterium Neisseria meningitidis. The bacteria can invade the body causing serious illness, including meningitis and septicemia—an infection of the bloodstream. (https://www.canada.ca/en/public-health/services/immunization/vaccine-preventable-diseases/invasive-meningococcal-disease/health-professionals.html)

Invasive Pneumococcal Disease (IPD), which involves serious and potentially fatal infections with the bacteria Streptococcus pneumonia, affects the blood or brain. IPD can lead to brain damage, blood stream infections or death. The very young (those under the age of 5) or the elderly (those 65 and older) are most at risk of IPD. Because pneumococcal bacteria can become resistant to treatment, a preventive measure such as having the pneumococcal vaccine is particularly important. (https://www.canada.ca/en/public-health/services/immunization/vaccine-preventable-diseases/invasive-pneumococcal-disease/health-professionals.html)<

Japanese encephalitis (JE) is a type of virus that is mainly transmitted to humans through the bite of an infected mosquito. JE occurs primarily in Asia`s rural agricultural areas, so there is a low risk for most travellers. (https://www.who.int/news-room/fact-sheets/detail/japanese-encephalitis)

A live virus vaccine contains a live, weakened (attenuated) virus that helps your body develop an immune response without you developing symptoms of the disease it is intended to prevent. The live vaccine relies on this weakened virus to "teach" your immune system to recognize the specific disease-causing pathogen and launch a defensive attack if it encounters it again. (https://www.verywellhealth.com/what-is-a-live-virus-vaccine-200925)

When symptoms of COVID-19 persist for more than 12 weeks after the infection. It's also known as Post Covid-19 and can affect both adults and children. (https://www.verywellhealth.com/what-is-a-live-virus-vaccine-200925)

Lyme disease is transmitted to humans through the bite of infected blacklegged ticks. Typical symptoms include fever, headache, fatigue, and a characteristic skin rash called erythema migraines. If left untreated, infection can spread to joints, the heart, and the nervous system. There is no evidence that Lyme disease can spread from person-to-person. (https://www.canada.ca/en/public-health/services/diseases/lyme-disease/prevention-lyme-disease.html)

Lymphatic Filariasis, also known as elephantiasis, is a debilitating and disfiguring disease caused by the thread-like parasitic worms, which live in the lymphatic system and can cause extreme swelling of the extremities and genitals. The disease is transmitted to humans by mosquitoes. Currently no vaccine exists for the disease. (https://www.who.int/news-room/fact-sheets/detail/lymphatic-filariasis)

Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female mosquitoes. (https://www.who.int/news-room/fact-sheets/detail/malaria)

Marburg virus disease (MVD) is a rare but severe hemorrhagic fever which affects both people and non-human primates. MVD is caused by the Marburg virus, a genetically unique zoonotic (or, animal-borne) RNA virus of the filovirus family. (https://www.cdc.gov/marburg/about/?CDC_AAref_Val=https://www.cdc.gov/vhf/marburg/index.html)

Measles is a highly contagious disease caused by a virus and can spreads easily when an infected person breathes, coughs or sneezes. It can cause severe illness, complications, and even death. It can affect anyone but is most common in children. Symptoms include a high fever, cough, runny nose and a rash all over the body. (https://www.who.int/news-room/fact-sheets/detail/measles)

A long-lived lymphocyte that carries the antibody or receptor for a specific antigen after a first exposure to the antigen and that remains in a less than mature state until stimulated by a second exposure to the antigen at which time it mounts a more effective immune response than a cell which has not been exposed previously. (https://www.merriam-webster.com/medical/memory cell)

Meningitis is an inflammation of the meninges (the lining of the brain and spinal cord); it can result from many different types of infections caused by viruses, bacteria, fungus or other organisms. (https://www.cdc.gov/meningitis/about/index.html)

Also known as Invasive Meningococcal Disease. Meningococcus is the common name for Neisseria meningitidis, a type of bacteria spread by the exchange of respiratory and throat secretions. Meningococcal diseases can be severe and include infections of the lining of the brain and spinal cord (meningitis) and bloodstream infections (bacteremia or septicemia). (https://www.canada.ca/en/public-health/services/immunization/vaccine-preventable-diseases/invasive-meningococcal-disease.html)

These are a series of vaccines that target the various strains of meningoccus bacteria and the protect against the meningococcal diseases. These immunizations include: Meningococcal A, C, Y, W135 Conjugate (Quadrivalent), Meningococcal Polysaccharide A, C, Y, W135 (Quadrivalent), and recently available Meningococcal Serogroup B. (https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-13-meningococcal-vaccine.html)

Microcephaly is a condition where a baby is born with a small head or the head stops growing after birth. (https://www.who.int/news-room/fact-sheets/detail/microcephaly)

• Multisystem inflammatory syndrome (MIS) can affect children (MIS-C) and adults (MIS-A).
• MIS is a rare but serious condition associated with SARS-CoV-2, the virus that causes COVID-19, in which different body parts become inflamed.

(https://www.cdc.gov/mis/about/?CDC_AAref_Val=https://www.cdc.gov/mis/about.html)

MMR is a combination immunization against measles, mumps, and rubella; in some cases, the immunization also includes varicella, and is referred to as MMRV. Children generally receive the MMR vaccination at 12 to 15 months of age and again at 18 months or 4 to 6 years of age. (https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-12-measles-vaccine.html)

MMRV vaccine can prevent measles, mumps, rubella, and varicella. Most people who are vaccinated with MMRV will be protected for life. (https://www.cdc.gov/vaccines/hcp/vis/vis-statements/mmrv.html)

Monkeypox is a viral zoonosis (a virus transmitted to humans from animals) with symptoms similar to those seen in the past in smallpox patients, although it is clinically less severe. (https://www.who.int/news-room/fact-sheets/detail/monkeypox)

A type of protein that is made in the laboratory and can bind to certain targets in the body, such as antigens on the surface of cancer cells. There are many kinds of monoclonal antibodies, and each monoclonal antibody is made so that it binds to only one antigen. Monoclonal antibodies are being used in the diagnosis and treatment of many diseases. (https://www.cancer.gov/publications/dictionaries/cancer-terms/def/monoclonal-antibody)

The proportion that becomes sick. (https://www.immunizationinfo.org/issues/general/understanding-vaccine-research-terms/#m)

The number of deaths within a particular society and within a particular period of time. (https://dictionary.cambridge.org/dictionary/english/mortality)

Also known as Vector borne diseases. Mosquito borne diseases are viral diseases which are transmitted through infected mosquitoes. (https://health-infobase.canada.ca/zoonoses/mosquito/)

mRNA vaccines are a new type of vaccine that don't contain viruses or bacteria. Instead, they contain instructions that teach our cells how to make proteins that will trigger an immune response. Once triggered, our body then makes antibodies and other immune responses. These immune responses help us fight the infection to prevent us from getting sick. (https://www.canada.ca/en/health-canada/services/drugs-health-products/covid19-industry/drugs-vaccines-treatments/vaccines/type-mrna.html)

Mumps is an acute infectious disease caused by the mumps virus. It is characterized by the swelling of one or more of the salivary glands, typically the parotid glands. Although generally mild, infection can result in complications such viral meningitis and orchitis /oophoritis. (https://www.canada.ca/en/public-health/services/immunization/vaccine-preventable-diseases/mumps/health-professionals.html)

a national advisory committee of experts in the fields of pediatrics, infectious diseases, immunology, pharmacy, nursing, epidemiology, pharmacoeconomics, social science and public health. NACI has been providing guidance on the use of vaccines currently or newly approved for use in Canada to the Government of Canada since 1964. (https://www.canada.ca/en/public-health/services/immunization/national-advisory-committee-on-immunization-naci/naci-membership-representation.html)

This type of vaccine contains killed (inactivated) germs or their parts. It's not possible to develop disease from non-live vaccines, like the injectable polio vaccine. This is because the killed germ can't reproduce or multiply. However, the body's defence system still recognizes parts of these germs as a foreign body, stimulating an immune reaction. (https://historyofvaccines.org/vaccines-101/what-do-vaccines-do/different-types-vaccines)

An outbreak of a disease refers to a higher number of cases than what is typically expected in a specific community, geographic area, or during a particular season. (https://www.emro.who.int/health-topics/disease-outbreaks/index.html)

An outbreak of disease that spreads throughout the world. (https://www.dictionary.com/browse/pandemic)

Passive immunization entails administering another person’s body to aid in preventing or combatting specific infectious diseases. This form of immunity is temporary but offers instant protection. Passive immunity can occur naturally, like when an infant acquires antibodies from their mother, or artificially, such as through antibody medications. (https://historyofvaccines.org/vaccines-101/what-do-vaccines-do/passive-immunization)

A pathogen is an agent, such as an organism, that causes disease. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5648414/#:~:text=What%20is%20a%20pathogen%3F,as%20unicellular%20and%20multicellular%20eukaryotes.)

Pertussis is a bacterial infection of the lungs and airways which is easily transmitted between individuals. It is also known as whooping cough, due to the serious coughing fits and “whooping” sound that may occur when catching the next breath. (https://www.canada.ca/en/public-health/services/immunization/vaccine-preventable-diseases/pertussis-whooping-cough.html)

Poliomyelitis (polio) is a highly infectious viral disease, which mainly affects young children. The virus is transmitted by person-to-person spread mainly through the faecal-oral route or, less frequently, by a common vehicle (e.g. contaminated water or food) and multiplies in the intestine, from where it can invade the nervous system and can cause paralysis.

Initial symptoms of polio include fever, fatigue, headache, vomiting, stiffness in the neck, and pain in the limbs. In a small proportion of cases, the disease causes paralysis, which is often permanent. There is no cure for polio, it can only be prevented by immunization. (https://www.who.int/health-topics/poliomyelitis#tab=tab_1)

A vaccine in which the immunogenic particles come from the carbohydrate-containing outer coatings of encapsulated bacteria. (https://historyofvaccines.org/educational-resources/glossary-terms)

A vaccine that works by stimulating an immune response against four different antigens, such as four different viruses or other microorganisms. For example, Gardasil is a quadrivalent vaccine that helps protect the body against infection with four different types of human papillomaviruses (HPV). (https://www.cancer.gov/publications/dictionaries/cancer-terms/def/quadrivalent-vaccine?redirect=true)

The isolation of a person or animal who is suspected of having a disease in order to prevent further spread of the disease. (https://www.merriam-webster.com/dictionary/quarantine)

Rabies is a viral infection in animals that can spread to humans. It is caused by a virus which attacks the nervous system and eventually affects the brain.

To cause an infection, the rabies virus must enter your body and reach your nerve cells. The virus then travels to your brain through your nerves. It reproduces in your brain and then travels back through your nerves to certain parts of your body and causes a variety of neurologic symptoms. (https://www.canada.ca/en/public-health/services/diseases/rabies/causes.html)

Recombinant viruses are genetically neutered or crippled so that they cannot reproduce and cause an infectious disease once they infect a target cell. (https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/recombinant-virus#:~:text=Recombinant%20viruses%20are%20genetically%20neutered,the%20retina%20(Table%2034.1))

Some countries require proof that you have received a certain vaccination before allowing you to enter the country. (https://travel.gc.ca/travelling/health-safety/vaccines)

In infectious disease terms, resistance refers to the ability to resist the effects of a pathogen, or infectious organism. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4368196/#:~:text=Resistance%20is%20defined%20as%20the,by%20a%20given%20pathogen%20burden.)

A major cause of respiratory illness in children. The virus usually causes a common cold. But sometimes it infects the lungs and breathing passages and can cause breathing problems in infants and young children. (https://kidshealth.org/en/parents/rsv.html#:~:text=What%20Is%20Respiratory%20Syncytial%20Virus,in%20infants%20and%20young%20children)

Rotavirus is a virus that has been known to cause rotavirus gastroenteritis in infants. Rotavirus gastroenteritis is a highly infectious form of diarrhoea in infants and young children that can cause severe vomiting and dehydration resulting in hospitalization and can be life-threatening. Children under five years of age, especially those between six months and two years, are most vulnerable to the disease. (https://www.canada.ca/en/health-canada/services/drugs-health-products/biologics-radiopharmaceuticals-genetic-therapies/activities/fact-sheets/questions-answers-porcine-circovirus-rotavirus-vaccines.html#q1)

Rubella, also known as “German measles”, it is caused by a virus and is highly contagious. Most people have mild symptoms including a rash, muscle aches, and low-grade fever. However, in a pregnant woman, it can result in miscarriage or fetal malformations. (https://www.canada.ca/en/public-health/services/diseases/rubella/causes-rubella.html#a1)

The production of antibodies (proteins) in the blood of a person who did not have the antibodies before. It occurs after vaccination or exposure to a virus or other substance. Testing for seroconversion can be used to look for the presence of an infection or disease or to see how well the body’s immune system responds to a vaccine. (https://www.cancer.gov/publications/dictionaries/cancer-terms/def/seroconversion)

Sexually transmitted diseases are infections spread mainly by contact with genitals or bodily fluids. Also called STDs, STIs or venereal disease, sexually transmitted infections are caused by bacteria, viruses or parasites.

Sexual activity includes genital touching or sexual intercourse. Anyone who is sexually active can get an STI. You can lower the risk of an STI, and one of the best ways is to talk about STIs with a new partner before sexual activity.

Some STIs cause no symptoms or only mild symptoms. But even with no symptoms, STIs can spread to others. Testing is the only way to be sure if you have an STI.

Some STIs are easy to treat and cure. Others are more complicated. Treatment is important so you don't spread the disease. Treatment also can help prevent fertility trouble, organ damage or some cancers. (https://www.mayoclinic.org/diseases-conditions/sexually-transmitted-diseases-stds/in-depth/std-symptoms/art-20047081)

Shingles is the name commonly used for herpes zoster, an infection that shows up as a painful skin rash with blisters, usually on part of one side of the body (left or right), often in a strip. People get shingles when the virus that causes chicken pox, varicella zoster, is reactivated in their body. The virus tends to reactivate when a person’s immune system is weakened because of another health problem. (https://www.canada.ca/en/public-health/services/infectious-diseases/fact-sheet-shingles-herpes-zoster.html)

Smallpox is an acute contagious disease, caused by the variola virus. It is transmitted from person to person via infected aerosols and droplets from infected symptomatic people. (https://www.who.int/health-topics/smallpox#tab=tab_1)

The term strain is used to distinguish a genetically distinct lineage separated from another strain by one or more mutations. A strain is a genetic variant (not to be confused with a viral variant) or subtype of microorganism (that could be a virus, but it also applies to bacteria and fungi). (https://www.news-medical.net/health/What-is-a-Viral-Strain.aspx#:~:text=What%20is%20a%20strain%3F,applies%20to%20bacteria%20and%20fungi).)

• Streptococcus pneumoniae bacteria cause pneumococcal disease.
• Certain ages and medical or other conditions put people at increased risk.
• Vaccination is recommended to prevent pneumococcal disease.

Streptococcus pneumoniae are lancet-shaped, gram-positive, facultative anaerobic bacteria with more than 100 known serotypes. Most S. pneumoniae serotypes can cause disease, but only a minority of serotypes produce the majority of pneumococcal infections. (https://www.cdc.gov/pneumococcal/hcp/clinical-overview/?CDC_AAref_Val=https://www.cdc.gov/pneumococcal/clinicians/streptococcus-pneumoniae.html)

a pathogenic microorganism and especially a bacterium that has developed resistance to the medications normally used against it. (https://www.merriam-webster.com/dictionary/superbug)

Open, subject, or unresistant to some stimulus, influence, or agency, ex: susceptible to pneumonia. (https://www.merriam-webster.com/dictionary/susceptible)

Medical care provided remotely to a patient in a separate location using two-way voice and visual communication (by computer or cell phone). (https://www.merriam-webster.com/dictionary/telemedicine#:~:text=Definition%20of%20telemedicine,chronic%20medical%20and%20mental%20disorders%20%E2%80%A6%E2%80%94)

Tetanus is a potentially fatal disease that can affect individuals of any age. It is caused by a bacterial spore that may be found in the intestines of animals and in the soil. It has been known as lockjaw due to the painful muscle contractions it causes in the muscles of the neck and torso. (https://www.canada.ca/en/public-health/services/immunization/vaccine-preventable-diseases/tetanus.html)

An ethylmercury compound used as a preservative. Thimerosal was used in many killed-virus vaccines until it was recommended to be removed from most childhood vaccines in 1999. It is still used in multi-dose influenza vaccines, and can be found trace amounts (a relic of the manufacturing process) in some other vaccines. (https://historyofvaccines.org/educational-resources/glossary-terms)

Tick-borne encephalitis is a viral disease that causes swelling of the brain, the membrane around the brain and spinal cord, and/or the spinal cord. It is transmitted through the bite of an infected tick. (https://www.canada.ca/en/public-health/services/diseases/tick-borne-encephalitis.html?_ga=1.210983381.1937082836.1455206125)

When travelling outside Canada, you may be at risk for a number of vaccine preventable illnesses. You may need additional vaccinations depending on your age, planned travel activities and local conditions of your destination. These are called travel vaccines. (https://travel.gc.ca/travelling/health-safety/vaccines)

Travelers' diarrhea (TD) affects between 30% - 70% of international travelers yearly, and can occur while traveling or after returning home. High-risk destinations include developing countries of Central and South America, Africa, the Middle East, and Asia. Infection is typically caused by ingestion of stool-contaminated food or water. (https://wwwnc.cdc.gov/travel/yellowbook/2024/preparing/travelers-diarrhea)

Tuberculosis (TB) is caused by bacteria (Mycobacterium tuberculosis) that most often affect the lungs. TB is spread from person to person through the air. Tuberculosis is curable and preventable. (https://www.who.int/news-room/fact-sheets/detail/tuberculosis)

Tularemia is a disease that can affect both animals and humans. Rabbits, hares, and rodents are particularly vulnerable and are known to die in large numbers during outbreaks. Humans can become infected through various means, such as

• Tick and deer fly bites
• Skin contact with infected animals
• Drinking contaminated water
• Inhaling contaminated aerosols or agricultural and landscaping dust
• Laboratory exposure

(https://www.cdc.gov/tularemia/index.html)

Typhoid fever is a vaccine preventable infection that is caused by the bacteria Salmonella typhi. It is common in developing countries with poor sanitation and low standards of hygiene. Typhoid is most often transmitted by eating food or drinking water that has been contaminated with the feces of an infected person. (https://www.who.int/news-room/fact-sheets/detail/typhoid#:~:text=Typhoid%20fever%20is%20a%20life,and%20spread%20into%20the%20bloodstream.)

A supply shortage of a vaccine is defined as an interruption of the supply from the manufacturer to the usual extent that is expected to last for more than two weeks or an unexpected, considerably increased demand which the manufacturer cannot meet to the appropriate extent. (https://www.pei.de/EN/medicinal-products/vaccines-human/supply-shortages/supply-shortages-node.html)p>

Vaccination is a simple, safe, and effective way of protecting you against harmful diseases, before you come into contact with them. It uses your body’s natural defenses to build resistance to specific infections and makes your immune system stronger.

Vaccines train your immune system to create antibodies, just as it does when it’s exposed to a disease. However, because vaccines contain only killed or weakened forms of germs like viruses or bacteria, they do not cause the disease or put you at risk of its complications. (https://www.who.int/news-room/questions-and-answers/item/vaccines-and-immunization-what-is-vaccination)

A form of a virus or disease that is slightly different from other forms. (https://dictionary.cambridge.org/dictionary/english/variant)

Varicella is known as chickenpox, is a very common and highly infectious childhood disease that is found worldwide. Symptoms appear 10 to 21 days after infection and last about 2 weeks. The defining symptom is a characteristic blister-like rash, which can cause severe irritation. Most children have a relatively mild illness, but severe illness may occur in adults and people with depressed immunity because of existing illness or because of a treatment that they are receiving (e.g. chemotherapy). The National Advisory Committee on Immunization (NACI) recommends immunization against varicella. (https://www.canada.ca/en/public-health/services/immunization/vaccine-preventable-diseases/varicella-chickenpox.html)

A smallpox immunization technique once practiced in many locations worldwide. Variolation involved the transfer of matter from a smallpox sore into a cut in the skin of an uninfected person. The variolated person would generally experience a local reaction or mild form of the disease and thereafter be immune to smallpox. Variolation was replaced with smallpox vaccination after Edward Jenner published his findings on the use of cowpox material to induce immunity to smallpox in 1798. (https://historyofvaccines.org/educational-resources/glossary-terms)

Vectors are living organisms that can transmit infectious pathogens between humans, or from animals to humans. Many of these vectors are bloodsucking insects, which ingest disease-producing microorganisms during a blood meal from an infected host (human or animal) and later transmit it into a new host, after the pathogen has replicated. Often, once a vector becomes infectious, they are capable of transmitting the pathogen for the rest of their life during each subsequent bite/blood meal. (https://www.who.int/news-room/fact-sheets/detail/vector-borne-diseases)

The ability of a pathogen to cause a disease. May also be used to describe the severity of the disease the pathogen causes. (https://historyofvaccines.org/educational-resources/glossary-terms)

A virus is an infectious microbe consisting of a segment of nucleic acid (either DNA or RNA) surrounded by a protein coat. A virus cannot replicate alone; instead, it must infect cells and use components of the host cell to make copies of itself. Often, a virus ends up killing the host cell in the process, causing damage to the host organism. Well-known examples of viruses causing human disease include AIDS, COVID-19, measles and smallpox. (https://www.genome.gov/genetics-glossary/Virus)

The progressive loss of protective antibodies against an antigen or disease that occurs with the passage of time. It is a crucial factor in vaccination. Booster doses of a vaccine are given when the immune response to an antigen drops below protective levels. (https://medical-dictionary.thefreedictionary.com/waning+immunity)

West Nile is a virus that is transmitted by the bite of an infected mosquito. These mosquitoes can spread the disease to humans and other animals. Symptoms range from mild fever, headache, rash, swollen lymph glands, to more severe: loss of consciousness muscle weakness and paralysis. There is no specific treatment or vaccine for West Nile virus infection in humans. Patients are treated for their symptoms. (https://www.canada.ca/en/public-health/services/diseases/west-nile-virus/treatment-west-nile-virus.html)

The World Health Organization (commonly known as WHO) is an agency of the United Nations, established in 1948, concerned with improving the health of the world's people and preventing or controlling communicable diseases on a worldwide basis through various technical projects and programs. (https://www.who.int/about)

See Pertussis

The yellow fever virus is found in tropical and subtropical areas of Africa and South America. The virus is spread to people by the bite of an infected mosquito. Yellow fever is a very rare cause of illness in U.S. travelers. Illness ranges from a fever with aches and pains to severe liver disease with bleeding and yellowing skin (jaundice). Yellow fever infection is diagnosed based on laboratory testing, a person’s symptoms, and travel history. There is no medicine to treat or cure infection. To prevent getting sick from yellow fever, use insect repellent, wear long-sleeved shirts and long pants, and get vaccinated. (https://www.cdc.gov/yellowfever/index.html)

Zika is caused by a virus transmitted by Aedes mosquitoes. People with Zika usually have symptoms that can include mild fever, skin rashes, conjunctivitis, muscle and joint pain, malaise or headache. There is no specific treatment or vaccine currently available. (https://www.who.int/news-room/fact-sheets/detail/zika-virus)

Zoonotic diseases (also known as zoonoses) are caused by germs that spread between animals and people. (https://www.cdc.gov/one-health/about/about-zoonotic-diseases.html?CDC_AAref_Val=https://www.cdc.gov/onehealth/basics/zoonotic-diseases.html)