Immunizations

Question 1

What are the contraindications to giving LAIV?

Answer 1

• Immunocompromising conditions
• Severe asthma (current active wheezing or currently on oral or high-dose inhaled GCs or medically attended wheezing in the previous 7 days)
• During pregnancy
• Children 2-17yo on ASA therapy (risk of Reye syndrome)
• Severe nasal congestion → defer until resolved or give IIV
• Close contact with severely immunocompromised (if LAIV given, avoid contact for 2wk)

Question 2

What is the dosage and frequency of influenza vaccines?

Answer 2

• IIV: 0.5 mL IM (exception: IIV3-Adj 0.25mL IM)
• LAIV4: 0.2mL (0.1mL in each nostril)
• Frequency:
  
  • <9yo: if first ever dose → need two doses at least 4wk apart
  • <9yo: if one dose previously → only one dose subsequently

Question 3

What is the first choice for influenza vaccine in the following groups?

1. Children 6-23mo
2. Children 2-17yo healthy / no immunosuppression
3. Children 2-17yo with immunosuppression
4. Pregnancy

Answer 3

1. IIV4 (high burden of influenza B)
2. LAIV4 or IIV4 (high burden of influenza B)
3. IIV4 (LAIV4 is contraindicated (can consider in well controlled HIV)
4. IIV4

Question 4

What are risk factors for HPV?

Answer 4

• Higher lifetime number of sexual partners
• Previous STIs
• History of sexual abuse
• Early age of 1st sexual intercourse
• Partner’s number of sexual partners
• Tobacco or marijuana use
• Immune suppression
• HIV infection
• MSM

Question 5

What are the types HPV mostly implicated in causing warts or cancer? What vaccines cover which viruses?

Answer 5

HPV types

• 6 & 11: benign and cause 90% of genital warts
• 16 & 18: pre-vaccine, caused 70% SCC, 86% adenocarcinoma of cervix, 90% of anal carcinomas, 50% of penile cancers, 43% vulvar cancers
• 31, 33, 45, 52, 58 (included in HPV-9) - cover 15-20% cervical, 24% vaginal, 9% penile, 2.5% of vulvar cancers

HPV Vaccines

• Optimal use: administration before exposure (i.e. before sexual activity)
• Three vaccines approved in Canada
  
  • Gardasil 9: HPV types 6, 11, 16, 18, 31, 33, 45, 52 and 58
  • Gardasil / HPV-4: types 6, 11, 16, 18
  • Bivalent: types 16, 18
• Efficacy is close to 100% against type-specific cervical disease
• Vaccinating may prevent transmission from women to men (but not MSM)

Question 6

What is the # of doses needed for HPV vaccine based on age group?

Answer 6

• Children 9-14yo (except if immunocompromised): 2 doses, at least 6mo apart
• People15-26yo: 3 doses