51. Immunization (6%)

Question 1

With parents who are hesitant to vaccinate their children, what to do? (2)

Answer 1

• explore the reasons
• and counsel them about the risks of deciding against routine immunization of their children.

Question 2

Name patients who will specifically benefit from immunization

Answer 2

• elderly and children
• immunosuppressed
• travellers
• those with sickle cell anemia (Drépanocytose)
• and those at special risk for pneumonia and hepatitis A and B)

Question 3

When to immunize? (4)

Answer 3

• In infancy
• Before pregnancy
• Before traveling
• When new to the country if not previously immunized

Question 4

Exploring fears and myths about immunizations : Side effects (2)

Answer 4

• Most common side effects are mild fever and sore extremity.
• Serious reactions (death, encephalopathy) are so rare that their incidence cannot be calculated.

Question 5

Exploring fears and myths about immunizations : Autism

Answer 5

• The original paper in the Lancet publishing this association was recently withdrawn and there have been no definitive cases to support this claim.
• This was originally associated with a preservative agent called thimerosal. The only vaccines in Canada that are given to children and contain thimerosal are the multidose influenza vaccine and Hepatitis B. Both these vaccinations are available in formulations that do not contain thimerosal (ex. Vaxigrip for children and pregnant mothers).
• The only true contraindication to thimerosal is anaphylaxis.

Question 6

Exploring fears and myths about immunizations : Vaccines don’t work

Answer 6

• No vaccine is entirely effective. If a vaccine-preventable disease outbreak does occur, some vaccinated individuals will contract the disease.
• However the proportion of unvaccinated individuals who contract the disease will be much higher than the proportion of vaccinated individuals.

Question 7

Exploring fears and myths about immunizations : “Vaccine-preventable diseases no longer exist in Canada “

Answer 7

• Certainly some vaccine-preventable diseases are rarely, if ever, seen in Canada and herd immunity for unvaccinated individuals does occur.
• However, unvaccinated individuals may still be exposed in their lifetime given the immigrant population that may not have been vaccinated or if the unvaccinated chooses to travel later in life.

Question 8

Why vaccinate?

Answer 8

• To protect yourself from common (HiB, Influenza, Varicella) or serious (Tetanus, Hepatitis, Meningococcemia) preventable infectious diseases.
• To protect individuals in society who are unable to receive vaccinations (newborns, immunocompromised, elderly)

Question 9

When should premature infants receive vaccines?

Answer 9

• Premature infants should receive immunizations at the same time (chronological age) as term infants, ie. do not delay vaccinations - in Quebec first vaccines at 2 months old
• Exception: In jurisdictions where Hep B vaccine is given at birth in HbsAg negative mother, delay until infant 2000g or discharged from hospital

Question 10

When to give Pneumococcal 23-valent vaccines ?

Answer 10

≥65yo, <65 with specific risk factors

Question 12

When to give Herpes zoster vaccine ?

Answer 12

• ≥60yo (consider 50-59yo), immunosuppressed
• Adults ≥50yo who are known VZV seronegative should be given univalent varicella vaccine rather than herpes zoster (routine testing not recommended)

Question 13

When to give : HPV4 or HPV9 ()

Answer 13

• 9-26yo and ≥27yo who are at ongoing risk
• PIQ recommends vaccinating women 9-45yo, men 9-26yo even if previous HPV exposure

Question 14

When to give : Tetanus/Diphtheria (Td) (2)

Answer 14

• Primary series for unimmunized, and booster every 10y (Note: In Quebec, current guideline is for one single booster after 50yo)
• Earlier if non-clean/minor wound (if fully vaccinated >5y, if not fully vaccinated needs complete series with Ig)

Question 15

When to give : Rabbies vaccine

Answer 15

Pre- or post-exposure if high-risk, consider call local public health for risk assessment

Question 16

When to give : Coqueluche accine (2)

Answer 16

• Once in adulthood (Tdap), as early as possible if close contact with young infants
• One dose during each pregnancy ideally between 26-32 weeks gestation

Question 17

When to give : Hep A&B vaccine

Answer 17

Risk or anyone who wants protection from hep B

Question 18

When to give : Meningococcal conjugate vaccine

Answer 18

Up to 24yo not immunized, or risk

Question 19

When to give : MMR vaccine

Answer 19

For susceptible adults born in or after 1970 or risk of exposure (traveller, healthcare worker, student, military)

Question 20

When to give : Varicella vaccine

Answer 20

If susceptible or seronegative (2 doses)

Question 21

When to give : Influenza vaccine

Answer 21

• Annually for all, focus on high risk (6mo-5yo, ≥65yo, chronic disease, pregnancy/postpartum, healthcare worker, frequent contact with above)
• Not recommended in <6 months old as effectiveness not proven
• Children <9yo are recommended to get 2 doses one month apart for their first influenza vaccine