A clinic nurse is reviewing 9-valent HPV vaccine records for several clients. None of the clients has received any other HPV vaccine, and none is pregnant. Which determinations by the nurse are correct? Select all that apply.

Quick answer
The 16-year-old needs one more dose, the 13-year-old needs a third dose, and the 23-year-old needs 3 doses (options 4, 2, 6).

Why this is correct
Apply the rules to each record. The 16-year-old started at 14, before the 15th birthday, so 2 doses complete the series; dose 2 is now due. The 13-year-old received dose 2 only 4 months after dose 1, less than the 5-month minimum, so a third dose is needed. The 23-year-old is starting at 15 or older and is within routine catch-up through age 26, so 3 doses are needed.

Easy analogy or mental picture
The HPV schedule is like a two-key lock opened by age at the first dose: start before 15 and 2 keys work, start later or with a weak immune system and you need 3 keys.

Memory hook
Start under 15 = 2 doses at least 5 months apart; 15 or older, or immunocompromised = 3.

NCLEX decision rule
Base the dose count on the age at the first dose, the actual interval between doses, and immune status, not on current age alone.

Why the other choices are wrong
The 2-dose series for the 14-year-old on chemotherapy (option 5) is tempting because the child started before 15, but immunocompromised clients need 3 doses regardless of start age. Declaring the 19-year-old ineligible (option 3) is tempting because vaccine does not treat existing infection, but it still protects against HPV types not yet acquired, and catch-up is recommended through age 26. Restarting the lapsed series (option 1) is tempting because a long gap feels like lost protection, but vaccine series are resumed where they stopped and never restarted.