2025 – PAGE 342 – VACCINES, IMMUNIZATIONS AND CONTRAINDICATIONS

HEPATITIS A VACCINE

Everyone gets the Hepatitis A vaccine. Starts at 1 year of age, and 2 doses are given 6 months apart.

HEPATITIS B VACCINE

Everyone gets the Hepatitis B vaccine. Start at birth and give 3 doses.

PEARL: The last dose SHOULD NOT be given prior to 6 months of age. The IDEAL regimen for you to remember is 0, 1, and then 6 months. Here are a few reasons why (but don’t memorize these details!):

• Must wait at least one month after dose #1 to give dose #2.
• Must wait at least two months after dose #2 to give dose #3.
• Dose #3 must NOT be given before the age of 24 weeks (6 months).
• SUMMARY: This means 0, 2, and 6 months is allowed. 0, 1, and 6 is allowed. 2, 4 and 6 is allowed because four months have passed between doses #1 and #3, and 2 months have passed between doses #2 and #3. Also, 0, 2, 4, and 6 IS ALLOWED because 4 months passed between the 2-month shot and the 6-month shot. The 4-month shot was likely a combination vaccine and just went to waste (and is allowed by the CDC to do so).

PEARLS: If mom’s Hepatitis B status is UNKNOWN, give the Hepatitis B vaccine within 12 hours of birth. Figure out mom’s status, and if she is HBsAg POSITIVE, give the immunoglobulin (HBIG) no later than the 7th day of life. If the status is already KNOWN to be positive, give BOTH the vaccine and the HBIG at birth.

MNEMONIC: There are three intervals to remember. Between #1 and #2 is FOUR weeks. Between #2 and #3 is double that (EIGHT weeks). Between #1 and #3 is double that (SIXTEEN weeks).

SPECIAL RULES FOR PREEMIES WITH BIRTHWEIGHT < 2000 g (low-yield for exam):

• If the mother’s status is positive or unknown: Give HBIG+ hepatitis B vaccine within 12 hours of birth; do not count the birth dose as part of the vaccine series, so administer 3 subsequent vaccine doses.
• If the mother’s status is negative: Delay first dose of hepatitis B vaccine until age 1 month or hospital discharge, then complete the series as usual.

HUMAN PAPILLOMA VIRUS VACCINE (HPV)

The HPV vaccine requires only 2 doses given at least 6 months apart starting at 11-12 years of age. If the series is started after 15 years of age, then 3 doses are required on a 0, 1-month (or 2-month), and 6-month schedule (#3 has to be given at least 6 months after #1). It’s recommended for males and females and can be administered as early as 9 years of age.

MENINGOCOCCAL VACCINE (AKA MENINGOCOCCUS VACCINE)

The meningococcal vaccine (subtypes ACWY) is recommended for ALL kids at 11 years of age, NOT just those starting at college and living in a dorm. It requires a booster. If started on time at 11 years of age, the booster is given at 16 years of age. Otherwise, at about 3 years after the first dose. For unimmunized freshman living in a dorm, give one shot and no booster. Another meningococcal vaccine (subtype B) is recommended for both low-risk (given between 16-23 years old) and high-risk populations (> 10 years old after an outbreak, spleen damage or removal, compliment immune deficiency, taking a drug called eculizumab, or microbiologists routinely working with N. meningitides). It also requires a booster.

PEARL: The minimum age is now 2 months. Children < 11 years of age may receive the vaccine if they are at high risk (asplenic, having complement deficiency, generally immunocompromised, or traveling to an endemic area).

PEARL: If a CLOSE INTIMATE contact of your patient has meningitis, give your patient prophylaxis with rifampin or ceftriaxone within 24 hours of diagnosis regardless of the immunization status. Close “intimate” contacts include household members, child-care center contacts (not elementary school classmates), and persons directly exposed to the patient’s oral secretions (e.g. kissing or endotracheal intubation/management).