Vaccines for the PEBC® Exam: Canadian Immunization Guide Review and Practice Questions

A contraindication means the risk of giving the vaccine outweighs the benefit, so you do not give it. A precaution is a condition that may raise the risk of a reaction or blunt the immune response. You usually defer, unless the benefit clearly outweighs the risk.

• Common live vaccines in Canada: MMR, varicella, MMRV, live attenuated influenza (nasal), yellow fever, oral typhoid and rotavirus. Shingrix is not live.
• Two live injectable vaccines: give them on the same day or at least 4 weeks apart. If the second is given sooner, it is considered invalid and should be repeated.
• Inactivated vaccines can be given at the same visit as, or any time before or after, other vaccines. Use separate sites and needles.
• Blood products and immune globulin can blunt the response to MMR and varicella vaccines. The CIG gives product-specific waiting intervals, so check the table rather than guessing.
• Pregnancy: live vaccines are generally avoided. Give MMR or varicella after delivery to non-immune patients (breastfeeding is not a barrier).

Observe every patient for at least 15 minutes after immunization, and 30 minutes when there is a specific allergy concern. Fainting (vasovagal syncope) is far more common than anaphylaxis: pallor and a slow pulse with no hives or breathing problems point to syncope.

1. Call for help and emergency services. Lay the patient down (on their side if vomiting, sitting up if breathing is hard).
2. Give epinephrine 1 mg/mL IM into the mid-anterolateral thigh: 0.01 mg/kg (0.01 mL/kg), maximum 0.5 mg per dose. Use measured weight when you can.
3. Repeat every 5 minutes if symptoms persist, and record the time of each dose.
4. Antihistamines are optional add-ons for itch and hives. They never replace or delay epinephrine.
5. Transfer everyone who received epinephrine to hospital, because biphasic reactions can occur. Report the event as an adverse event following immunization (AEFI).

• Store refrigerated vaccines at 2 to 8 °C in a purpose-built or monitored fridge, never in the door. Frozen products follow their monograph.
• Do not use a refrigerated vaccine that has been frozen, and never use frozen diluent.
• After a temperature excursion: label the vaccine "Do not use", keep it at 2 to 8 °C, record the details (lot, expiry, temperatures, duration) and contact public health or the supplier before using or discarding it.
• If doses were already given from a compromised supply, public health may advise revaccination or serology.

Which vaccines a pharmacist may give, from what age, and whether a prescription is needed varies by province and territory. Some programs are publicly funded only in certain settings. Check your regulator and provincial program. The exam tests national principles, not one province's age cut-offs.

• Deferring a vaccine for a cold or mild fever. Minor illness is not a reason to wait.
• Withholding influenza vaccine because of egg allergy.
• Picking the deltoid or the subcutaneous route for anaphylaxis. The answer is IM into the thigh.
• Thinking Tdap given in an earlier pregnancy covers this one. It is every pregnancy.
• Treating Shingrix as a live vaccine. It can be given to immunocompromised adults.
• Giving a second live injectable vaccine 1 to 3 weeks after the first.
• Using a vaccine after a fridge excursion without checking with public health.

Immunization often comes up in chronic disease cases too. Patients with diabetes qualify as higher risk for influenza and pneumococcal disease. See the exam guide for how these topics are weighted.

• Previous anaphylaxis to the same vaccine or a component: refer to an allergist.
• Severe immunosuppression (for example high-dose corticosteroids, chemotherapy, biologics, transplant) before any live vaccine.
• Any reaction needing epinephrine: emergency transfer, then AEFI reporting.