Contraindications and precautions: Canadian Immunization Guide
Introduction
Sometimes vaccines cannot be given or need to be delayed due to contraindications or precautions. Other times people have concerns that lead to hesitation or refusal to get vaccinated. It is important that vaccine providers correctly identify contraindications, distinguish them from precautions, and seek expert advice as needed.
Contraindications and precautions
A contraindication is a situation in which a drug, such as a vaccine, should not be used because the risk outweighs any potential therapeutic benefit.
A precaution is a condition that may increase the risk of an adverse reaction following immunization or that may compromise the ability of the vaccine to produce immunity. In general, vaccines are deferred when a precaution is present. However, there may be circumstances when the benefits of giving the vaccine outweigh any potential risks, or when reduced vaccine immunogenicity may still result in significant benefit to an immunocompromised host.
Contraindications and precautions are determined by a person's past immunization experience(s), known allergies, current health status (for example: acute illness, immunocompromised status, chronic disease, pregnancy and breastfeeding) and presence of close contacts who might be affected by the use of live attenuated vaccines.
Some precautions and contraindications depend on whether a vaccine is a live attenuated product or non-live product. For information on types of vaccines, refer to  in Part 1. For complete vaccine-specific contraindications and precautions, consult the relevant  in Part 4, the product leaflet, or information contained within the vaccine's product monograph available through Health Canada's .
Vaccine providers should question all clients about their past immunization experience(s), known allergies, current health, and any chronic conditions to identify contraindications and precautions to the vaccine before each dose of vaccine is given. Checklists and routine screening questions are useful and can be found in  in Part 1.
The following is a general discussion of the key categories of events or underlying illness or conditions that may result in a contraindication and/or precaution to immunization.  features a summary of the contraindications and precautions associated with conditions that may be present in vaccine candidates.
Contraindications and precautions associated with specific conditions

# Acute Illness

## Moderate to Severe Acute Illness
The risks and benefits of vaccinating a severely ill person need to be assessed. The benefits of protection in a high risk exposure situation or when the window of opportunity is short (i.e., when travel or use of immunocompromising medications are imminent) need to be assessed against the risks of a vaccine-related adverse event. It is possible that systemic adverse events may complicate the medical management of an acute illness or that events associated with the acute illness may be misperceived as vaccine-related adverse events. Expert opinion is recommended in this situation.
Situations with specific contraindications or precautions include:
- Gastroenteritis
	+ Postpone oral typhoid, cholera and travellers' diarrhea vaccines until the illness has resolved.
	+ Defer rotavirus vaccine until condition improves unless deferral results in scheduling the first dose beyond the recommended age limit.
- Inflammatory eye disease treated with steroids
	+ Defer first-generation smallpox vaccine, if a non-outbreak situation, until condition resolves or course of steroids is completed.
- Measles
	+ Delay varicella containing vaccine for 6 weeks (a minimum of 4 weeks delay can be applied if needed).
- Medically attended wheezing in the 7 days prior to vaccination
	+ Live Attenuated Influenza Vaccine (LAIV) is contraindicated.
- Tuberculosis, active, untreated
	+ Tuberculosis may be exacerbated by natural measles infection. Although there is no evidence that measles or varicella-containing vaccines have such an effect, measles-mumps-rubella (MMR), measles-mumps-rubella-varicella (MMRV), varicella, and live zoster vaccines (LZV) are contraindicated as a precautionary measure.

## Mild Acute illness
Mild illnesses, with or without fever (e.g., upper respiratory tract infection, otitis media) do not increase the risk of adverse events following immunization or interfere with the response to vaccines. There are no associated contraindications or precautions and these should not be used as a reason to withhold or delay immunization.
The single exception is when nasal congestion is present that could impede the delivery of LAIV to the nasopharyngeal mucosa. In such cases, non-live influenza vaccine can be offered.

# Adverse events following a previous immunization
There are numerous adverse events following a previous immunization that may lead to concern regarding subsequent immunization.

## Anaphylactic reaction to a vaccine or a component of a vaccine
A vaccine is contraindicated in a person with a documented history of confirmed anaphylaxis after previous administration of the same vaccine although exceptions may apply (i.e., Imvamune and mRNA COVID-19 vaccines). Refer to the  in Part 4 for more information. If there is uncertainty regarding the diagnosis of anaphylaxis or which vaccine or vaccine component may have triggered it, consultation with an expert is recommended.

## Febrile seizure following immunization
There are no contraindications or precautions associated with a history of a febrile seizure after a previous immunization. Children with a history of febrile seizures have no increased risk of developing a seizure disorder.

## Guillain-Barre syndrome (GBS) with onset within 6 weeks of immunization
Cases of GBS have been reported following immunization but the evidence only supports a causal association for two vaccines: influenza and tetanus toxoid-containing vaccines. For influenza vaccine, the evidence suggests that the absolute risk of GBS in the period following seasonal or A(H1N1)pdm09 influenza vaccination is about one excess case per 1 million vaccine doses. However, the risk is higher following wild type influenza infection with approximately 17 cases of GBS per million influenza coded health care encounters (proxy measure for influenza infection). Thus, the risk of GBS associated with influenza vaccination must be balanced against the risk of GBS associated with influenza infection itself.
The evidence for a causal association between tetanus toxoid-containing vaccines and GBS is informed by a single individual who developed GBS following each of three doses of tetanus toxoid given years apart. There are no confirmatory epidemiologic studies and, at most, it is a very rare event.
As a precaution, it is recommended that persons who develop GBS within 6 weeks of receipt of a tetanus or influenza vaccine should not receive further doses of that specific vaccine. If there is a history of both *Campylobacter- infection (which has been associated with GBS) and immunization within 6 weeks before the onset of GBS, consultation with an infectious disease specialist is advised. Those who develop GBS outside the 6-week interval may receive subsequent doses of the vaccine.

## Hypotonic-hyporesponsive episode (HHE) following immunization
HHE is the sudden onset of hypotonia, hyporesponsiveness and pallor or cyanosis that may follow immunization in the first 2 years of life. It is thought to be a pain response. There are no contraindications or precautions associated with a history of HHE. There is evidence that there are no adverse consequences to these events. The risk of recurrence with subsequent vaccinations is low (<5%).

## Persistent crying following immunization
There are no contraindications or precautions associated with a history of persistent crying following immunization. Such reactions, which may be accompanied by an unusual high-pitched cry, are likely to be responses to pain at the site of injection in young infants. There are no associated sequelae. For information on techniques to decrease injection site pain, refer to  in Part 1.

## Oculorespiratory syndrome (ORS)
Oculorespiratory syndrome is defined as bilateral conjunctivitis plus one or more respiratory symptoms: cough, wheeze, chest tightness, difficulty breathing, difficulty swallowing, hoarseness or sore throat, with or without facial edema that starts within 24 hours of influenza vaccination. It is usually transient, resolving within 48 hours of onset. The only associated precaution is when lower respiratory symptoms accompany ORS, in which case expert review is required prior to subsequent immunization. For more information, refer to  in Part 4.

## Severe injection site reaction
Most injection site reactions are simply a normal inflammatory response to the vaccine. They are common and generally mild. These inflammatory reactions are not indicative of an allergy to the vaccine and patients can receive subsequent vaccinations.
An injection site reaction can be considered severe based on its size or location (e.g., 10cm, crossing the adjacent joint), duration (e.g., 4days) or impact on daily activities (e.g., required a consultation or hospitalization, prevented daily activities, resulted in missing work/school/daycare). There are specific types of severe injection site reactions like extensive limb swelling (ELS) or Arthus-type injection site reaction. A severe injection site reaction to one vaccine is not associated with an increased risk of injection site reactions to other vaccines. Repeating a dose of a vaccine that was previously associated with a large injection site reaction may result in a similar reaction; however, there is no increased risk of anaphylaxis. The presence of a large injection site reaction to a previous dose is not a contraindication to continuing the recommended schedule.
Severe Arthus-type injection site reactions are occasionally reported following receipt of diphtheria toxoid or tetanus toxoid-containing vaccines. There may be extensive painful swelling around the injection site, often involving the arm from shoulder to elbow and generally beginning 2 to 8 hours after injection. Persons who have experienced a previous Arthus-type injection site reaction should not receive further routine doses of Td/Tdap vaccine for at least 10 years. A pregnant person with a history of Arthus-type injection site reaction within the past 10 years should be referred to a specialist prior to re-vaccination with Tdap.
For information on wound prophylaxis following a tetanus-prone injury, refer to the  section of the  chapter in Part 4.

## Extensive limb swelling (ELS) following immunization
There are no contraindications or precautions associated with a history of ELS, which is defined as swelling with or without redness that extends at least to the joints immediately above and below the injection site and that may cross one or both joints or involve the entire limb where the vaccine was administered. The reaction is often painless. It is commonly (2-6%) seen in children receiving the 4th or 5th dose of DTaP containing vaccine and has also been reported after non-live influenza vaccination. For children who have had an episode of ELS, repeat episodes with the next dose of vaccine are very common (>10%). However, ELS resolves spontaneously within a few days, is not associated with any other complications, and repeat episodes are generally of less or the same intensity as the first episode.

## Syncope
There are no contraindications or precautions associated with a history of syncope (fainting) after a previous immunization. The likelihood of fainting can be reduced by measures that lower stress in those awaiting immunization, such as short waiting times, comfortable room temperature, preparation of vaccines out of view of recipients, and privacy during the procedure. People should be immunized while seated or lying down.
For more information, refer to .

# Allergies
A history of allergies is one of the most common concerns that people have about receiving vaccines. There are many types of allergic reactions and it is important to differentiate among them when considering implications for immunization.
Allergic reactions can be either immediate or delayed. Anaphylaxis is a serious, potentially life-threatening allergic reaction to foreign antigens; it has been causally associated with vaccines with an estimated frequency of 1.3 episodes per million doses of vaccine administered. In anaphylaxis, signs and symptoms have a sudden onset and progress rapidly over several minutes and involves two or more body systems. This immediate hypersensitivity reaction is IgE mediated (Type 1) and usually occurs within minutes up to 4 hours after injection; most within 2 hours.
The mechanisms of delayed reactions to vaccines are not fully understood. These may appear several hours to days after immunization. These reactions include an Arthus-type or Type 3 reaction (a local vasculitis due to deposition of IgG-based immune complexes in dermal blood vessels), a cell-mediated, delayed hypersensitivity or Type 4 reaction, or other unknown mechanisms.
On close questioning, it may become evident that people think they have an allergy to a vaccine or vaccine component but it is not a true allergy. People can be reassured that it is highly unlikely that they are allergic to a vaccine or vaccine component if they have a delayed, localized reaction.
People with a suspected moderate to severe hypersensitivity reaction, should seek expert advice. Suspected hypersensitivity should not be an ongoing reason to not administer vaccine. It should be investigated by an expert to clarify whether the person may proceed with vaccination or not. For more information, refer to .

## Allergy to a vaccine component or its container
Vaccine is contraindicated in persons with proven immediate or anaphylactic hypersensitivity to any component of the vaccine (with the exception of ) or its container (e.g., latex). Assessment by an allergist is warranted if further vaccine doses are needed. There is general evidence that some individuals with proven immediate or anaphylactic hypersensitivity to vaccine component(s) or with immediate allergic reactions to vaccines can safely receive a subsequent dose of the same vaccine with low risk of a systemic reaction under the supervision of an allergist. For guidance on specific vaccine(s), consult the relevant  in Part 4.
Precaution is warranted in situations of suspected hypersensitivity or non-anaphylactic allergy to a vaccine or its components. Investigation is indicated which may involve immunization in a controlled setting. Consultation with an expert may be advised. For guidance on specific vaccine(s), consult the relevant  in Part 4.
People may report an allergy to a number of vaccine components including:
- Gelatin - Patients with a history of anaphylaxis to gelatin need to be assessed by skin testing to gelatin before vaccine with gelatin component is given. Most gelatin allergies are non-anaphylactic.
- Latex - Anaphylactic allergy to latex is very rare but if confirmed would pose a contraindication to the use of vaccines that come in vials with latex stoppers or that include syringes with latex components. For non-anaphylactic latex allergies (e.g., history of contact dermatitis to latex gloves), vaccines supplied in vials or syringes that contain dry natural rubber or natural rubber latex may be given.
- Neomycin - Neomycin allergy is most often a contact dermatitis (i.e., a delayed hypersensitivity reaction) which is not a contraindication for administration of vaccines containing neomycin.
- Thimerosal - Even if there is a documented history of a delayed hypersensitivity reaction to thimerosal (such as a large local reaction or contact dermatitis), immunization with thimerosal-containing vaccines can proceed. In the rare instance of individuals with proven delayed hypersensitivity to thimerosal, they should be advised that long-lasting local or systemic cutaneous reactions can occur. They should report any reaction of concern following immunization so that it can be managed appropriately.
For a list of potential allergens, refer to  in Part 1.

## Egg allergy
Egg allergy is one of the most common food allergies of childhood, with a prevalence of approximately 2% in children. It is often associated with eczema in infants and asthma in young children. However, allergic diseases are not a contraindication to immunization with egg protein-containing vaccine.
As most children outgrow their egg allergy, the prevalence of egg allergy in adulthood is lower and is estimated at 0.7%. The most common egg allergy is to egg white. Anaphylaxis to egg is possible.
In Canada, there are several vaccines manufactured by processes involving hens' eggs or their derivatives, such as chick cell cultures. This manufacturing process may result in the following vaccines containing trace amounts of residual egg and chicken protein:
- measles-mumps-rubella (MMR) vaccines
- measles-mumps-rubella-varicella (MMRV) vaccines
- influenza vaccines grown in eggs or chick cell cultures
- RABAVERT rabies vaccine
- yellow fever (YF) vaccine
- Imvamune Smallpox Vaccine
Previous concerns about immunizing egg-allergic individuals with vaccines that contain egg protein have been allayed by several studies resulting in clear changes to expert recommendations for some, but not all, of the above vaccines. A known egg allergy is not a contraindication to MMR, MMRV, Imvamune or influenza vaccines. Refer to  in Part 4 for additional information.

## Measles and mumps-containing vaccine
MMR or MMRV vaccine can be administered in the routine manner to people who have a history of anaphylactic hypersensitivity to egg. Numerous studies of egg-allergic subjects have shown that there is no increased risk of allergic reaction to MMR vaccine in those with egg allergy. The trace amount of egg protein in both MMR and MMRV vaccines are insufficient to cause an allergic reaction in egg-allergic individuals. Skin testing is not recommended prior to vaccination as it does not predict reaction to the vaccine. Hypersensitivity reactions that do occur following MMR and MMRV vaccine are usually due to other components of the vaccine, such as gelatin or neomycin.

## Influenza vaccine
Studies have clearly demonstrated that egg-allergic persons can receive influenza vaccine. All egg-allergic individuals may be vaccinated against influenza using any of the vaccines authorized for use in Canada. Although the egg albumin (egg protein) content in influenza vaccines manufactured in eggs may vary from year to year, vaccines marketed in Canada are approved with a maximum allowable egg albumin content that is associated with low risk of adverse events.
The full recommended dose can be used and there is no need for a prior influenza vaccine skin test irrespective of a past severe reaction to egg. The vaccine may be given in any setting where vaccines are routinely administered. Refer to the Additional Vaccine Safety Considerations in the  for safety data supporting this recommendation for inactivated influenza vaccine (IIV) and LAIV.

## Imvamune vaccine
Imvamune vaccine is prepared from virus grown in chicken embryo fibroblast cells. However, the risk associated with the trace amounts contained in the vaccine is thought to be low. The full recommended dose can be used and there is no need for a prior vaccine skin test irrespective of a past severe reaction to egg. The vaccine may be given in any setting where vaccines are routinely administered. Prolonged observation (30 minutes) may be considered.

## Rabies vaccine
RABAVERT rabies vaccine is grown in chick embryo cell culture. Imovax rabies vaccine is manufactured using human diploid cell cultures and therefore egg protein contamination is not an issue. For pre-exposure vaccination, Imovax rabies vaccine should be given to persons with a history of hypersensitivity reactions to egg or egg products as a precautionary measure. For post-exposure prophylaxis, the use of Imovax  vaccine is preferred for persons with a history of hypersensitivity to egg. If Imovax  vaccine is not available, RABAVERT vaccine should be administered with strict medical monitoring and facilities for emergency treatment of anaphylactic reactions readily available.

## Yellow fever vaccine
Yellow fever (YF) vaccine is prepared from virus grown in chick embryos and is the vaccine most likely to contain sufficient amounts of egg or chicken proteins to cause an allergic reaction in egg-allergic or chicken-allergic individuals. There have been several reports of anaphylactic reactions to YF vaccine in egg-allergic or chicken-allergic individuals; therefore, Yellow fever vaccine should not be routinely administered to egg-allergic or chicken-allergic individuals. Referral of egg-allergic or chicken-allergic individuals to an allergy specialist is recommended, as YF vaccination may be possible after careful evaluation, skin testing and graded challenge or desensitization.

## Individuals should be asked about allergies to egg or chicken prior to vaccination with Yellow fever or RABAVERT rabies vaccines.

# Concurrent or recent medication including biologics

## Antibiotic therapy
Antibiotic therapy does not interfere with response to non-live vaccines or most live vaccines with the following exceptions:
- The Typh-O vaccine series should be finished at least 3 days before commencing, or initiated at least 3 days after completing, treatment with sulphonamides or other antibiotics active against *S. typhi*, or antimalarials. Exceptions include chloroquine, mefloquine and atovaquone/proguanil (Malarone), as these antimalarials do not affect the immune response to Typh-O vaccine and can be administered at the same time as, or at any interval before or after Typh-O vaccine.
- Bacille Calmette-Guerin (BCG) vaccine should not be administered to individuals receiving drugs with anti-tuberculous activity, including fluoroquinolones.

## Anticoagulation
Individuals receiving long-term anticoagulation with either warfarin or heparin are not considered to be at higher risk of bleeding complications following immunization and may be immunized through either the intramuscular or subcutaneous route (as recommended for the vaccine product) without discontinuation of anticoagulation therapy. For intramuscular injection, use a small gauge needle (23 gauge or smaller) and apply firm pressure to the injection site for  2 minutes. There is a paucity of evidence on whether there is an increased risk of bleeding complications following immunization with the other types of anticoagulants, such as antiplatelet agents, but there is no reason to believe that persons receiving these anticoagulants need to be treated any differently from those receiving other anticoagulants.

## Antiviral therapy
Antiviral therapy does not interfere with response to non-live vaccines or most live vaccines with the following exceptions:
- Varicella vaccine and live herpes zoster (LZV) vaccine may have reduced effectiveness if given concurrently with antivirals active against varicella zoster virus (such as acyclovir, valacyclovir, famciclovir). People taking long-term antiviral therapy should discontinue these drugs, if possible, from at least 24 hours before administration of varicella or LZV vaccine and should not restart antiviral therapy until 14 days after vaccination.
- LAIV should not be administered until 48 hours after antiviral agents active against influenza (e.g., oseltamivir) are stopped, and antiviral agents should not be administered until at least 14 days after receipt of LAIV unless medically indicated. If antiviral agents are administered within this time frame (from 48 hours before to 14 days after LAIV), revaccination should take place at least 48 hours after the antivirals are stopped.

## Recent administration of blood products containing antibodies
Passive immunization with human immunoglobulin or receipt of most blood products can interfere with the immune response to MMR, MMRV and univalent varicella vaccines. Measles-containing or varicella vaccines should be given at least 14 days prior to administration of an immunoglobulin preparation or blood product, or delayed until the antibodies in the immunoglobulin preparation or blood product have degraded. Respiratory syncytial virus monoclonal antibody (RSVAb) does not interfere with live vaccines because RSVAb contains only antibody to respiratory syncytial virus. For more information, refer to Table 1 in  in Part 1.
A risk-benefit assessment is needed for post-partum women who have received Rh immunoglobulin (RhIg) and require MMR or varicella vaccine. For more information, refer to  in Part 1.
In adults with pre-existing antibody to varicella-zoster virus (VZV), in theory, administration of immunoglobulin should not interfere with the LZV response. For this reason, some experts do not consider recent administration of Ig or blood products as a reason to delay the administration of LZV. LZV should be considered only in cases where the recombinant zoster vaccine is contraindicated, unavailable or inaccessible.

## Salicylates
While it is generally safe to be immunized when taking salicylates (acetylsalicylic acid, aspirin, or ASA) there are some exceptions:
- LAIV is contraindicated in children and adolescents (2-17 years of age) currently receiving salicylates (e.g., ongoing treatment with aspirin-containing therapy) because of the association of Reye's syndrome with ASA and wild-type influenza infection. Non-live influenza vaccine should be used instead. ASA-containing products should be delayed for 4 weeks after receipt of LAIV in children aged 2 - 17 years, unless a risk assessment deems that the benefits outweigh the potential risks for the individual (e.g., treatment of Kawasaki disease).
- Varicella-containing vaccine manufacturers recommend avoidance of salicylate therapy for 6 weeks after varicella immunization because of an association between wild-type varicella, salicylate therapy and Reye's syndrome. Health care providers should weigh the theoretical risks associated with varicella vaccine against the known risks associated with wild-type varicella. Because adverse events have not been reported with the use of salicylates after varicella immunization, people with conditions requiring chronic salicylate therapy should be considered for immunization, with close subsequent monitoring.

# Other Situations, Underlying Condition or Illness
Chronic conditions with no contraindications or precautions are not included in the list below. However, it is important to ensure that individuals with chronic conditions are immunized appropriately since they are often at higher risk of complications due to vaccine-preventable diseases. For detailed recommendations on the use of live and non-live vaccines in individuals with asplenia or hyposplenia, endocrine/metabolic disease, heart disease, non-malignant hematologic disorders, inflammatory diseases, renal disease and dialysis, liver disease, lung disease and neurologic disorders, refer to  in Part 3.

## Asthma, severe
Live attenuated influenza vaccine (LAIV) is contraindicated in individuals with severe asthma (defined as currently on oral or high dose inhaled glucocorticosteroids or active wheezing) or those with medically-attended wheezing in the 7 days prior to vaccination. LAIV can be used in stable, non-severe asthmatics.

## Bleeding disorders
People with bleeding disorders should receive all recommended immunizations according to routine schedules when appropriate safety measures have been taken. Control of bleeding disorders should be optimized prior to immunization. Vaccine providers should ensure that there are no symptoms or signs compatible with an undiagnosed bleeding disorder (e.g., unexplained bruising). If such indicators are present before immunization, a diagnosis should be established before commencing immunization. When administering a parenteral vaccine, consider the use of a small gauge needle (23 gauge or smaller) and apply firm pressure for  2 minutes after the immunization.
For more information, refer to  in Part 3.

## Congenital malformation of gastrointestinal tract or history of intussusception
Rotavirus vaccine is contraindicated in infants with a history of intussusception or uncorrected congenital malformation of the gastrointestinal tract that would predispose for intussusception.

## Immunocompromised persons
For contraindications and precautions regarding immunization of individuals with primary immunodeficiencies, hematopoietic stem cell transplant candidates/recipients, solid organ transplant candidates/recipients and HIV-infected persons, refer to  in Part 3. Contraindications and precautions are also provided for individuals slated for, or on, immunosuppressive therapy including infants of mothers treated during pregnancy.

## Positive Tuberculin skin test
BCG vaccine is contraindicated for individuals with a positive tuberculin skin test, although immunization of tuberculin reactors has occurred frequently without complications.

## Pregnancy and Breastfeeding
For contraindications and precautions regarding immunization during pregnancy and breastfeeding, refer to  in Part 3.

## Preterm infants
Healthy preterm infants weighing 1,500 grams or more at birth generally tolerate immunizations well, with rates of adverse events similar to the low rates of full-term infants. Hospitalized premature infants should have continuous cardiac and respiratory monitoring for 48 hours after their first immunization. For more information, refer to  in Part 3.

## Skin Disorders
Vaccines are generally safe for people with skin disorders. For comfort, administer vaccine into a non-affected area. Some smallpox vaccines and BCG are exceptions to this. Imvamune vaccine can be safely administered in people with eczema (atopic dermatitis). BCG vaccine is contraindicated when there is extensive skin disease or burns.
For more information, refer to the  and  chapters in Part 4.

## Thymus disease
For individuals with a past history of thymus disease with abnormal immune function (e.g., thymoma, thymectomy, myasthenia gravis), Yellow fever vaccine is contraindicated because of an increased risk of viscerotropic disease.
Close Contacts of Immunocompromised or Pregnant Individuals
Vaccination provides protection at both an individual and population level. Some people may have conditions that preclude vaccination, but they can be protected by having the people around them vaccinated. Immunization of household contacts of immunosuppressed persons, pregnant women, and neonates provides important protection against transmission of disease in the household.
Up-to-date routine immunizations are recommended for household contacts of pregnant women, immunocompromised persons, and neonates with the following exceptions:
- Non-live influenza vaccine is preferred over LAIV for those in close contact with severely immunocompromised persons.
- Oral polio vaccine (OPV): OPV is not used in Canada but individuals may receive it in other countries. Household contacts who are vaccinated with OPV should not have contact with immunocompromised persons for six weeks after receipt of OPV.
- Following MMRV, varicella or LVZ vaccines, if a vaccine recipient develops a varicella-like rash, the rash should be covered and the vaccinee should avoid direct contact with the immunocompromised person for the duration of the rash.
- First-generation smallpox vaccine should not be administered to household contacts of an immunocompromised person in a non-emergency situation.
- First-generation smallpox vaccine: Vaccinees with household and other close contacts with active eczema or a history of eczema or other exfoliative skin conditions, immunosuppressive disorders, or with close contact with infants or pregnant women, should take special precautions in order to prevent viral transfer to these contacts.
 Pre-exposure: use Imovax
 Post-exposure: Imovax preferred but if unavailable administer RABAVERT ensuring strict medical monitoring with readily available emergency treatment for anaphylaxis
Exceptions may apply (i.e., Imvamune and mRNA COVID-19 vaccines).
Exceptions may apply (i.e., Imvamune and mRNA COVID-19 vaccines).
2. Intermittent
2. Children and adolescents should avoid salicylates following :- LAIV for 4 weeks
- Varicella-containing vaccine for 6 weeks
OPV: avoid direct contact with immunocompromised person(s) for 6 weeks after receipt of OPV in another country
Varicella vaccine recipients with varicella-like rash: ensure that rash is covered and avoid direct contact with the immunocompromised person for the duration of the rash
Those who develop GBS outside the 6 week interval may receive subsequent doses of the vaccine.
Salicylates are avoided in these instances to decrease the risk of Reye's syndrome.
Severe asthma: defined as currently on oral or high dose inhaled glucocorticosteroids or active wheezing.
Because of an association between a history of thymus disease and acute viscerotropic disease.
Oral polio vaccine is neither recommended nor available in Canada.
BCG
Bacille Calmette-Guerin vaccine
ELS
extensive limb swelling
GBS
Guillain-Barre syndrome
HHE
hypotonic-hyporesponsive episode
HPV
human papillomavirus vaccine
Ig
immunoglobulin
LAIV
live attenuated influenza vaccine
LZV
live zoster vaccine
MMR
measles-mumps-rubella vaccine
MMRV
measles-mumps-rubella-varicella vaccine
OPV
-ral polio vaccine
ORS
-culorespiratory syndrome
RV
rotavirus vaccine
Tdap
tetanus toxoid, diphtheria toxoid (reduced), acellular pertussis (reduced) vaccine
VZV
varicella-zoster virus
YF
yellow fever
Chapter revision process
The CIG Part 2 Working Group members reviewed the chapter to ensure content was up-to-date with clinical practice and evidence based. The revised guidance on the pressure time post administration of a parenteral vaccine to persons with a bleeding disorder or on an anticoagulant were based on a review of the literature, a review of guidance provided by other National Immunization Technical Advisory Groups (NITAGs) and expert opinion. For persons with a history of thymus disease with abnormal immune function, guidance regarding YF vaccine administration was changed from "generally not recommended" to "contraindicated" following a literature review. Updated guidance on contraindications and precautions associated with allergies is based on the guidance on Imvamune vaccine in those with allergic/immunocompromising conditions from the Canadian Society of Allergy and Clinical Immunology (CSACI) as of November 1, 2022.