What is the recommended dose and administration schedule of Pneumovax 23 (pneumococcal polysaccharide vaccine) for adults 65 years and older or those with underlying medical conditions?

Pneumovax 23 Dosing and Administration

For adults ≥65 years or those with underlying medical conditions, Pneumovax 23 (PPSV23) is no longer the preferred initial pneumococcal vaccine—instead, a single dose of PCV20 or PCV21 should be given first, with PPSV23 reserved only for specific sequential vaccination scenarios when PCV15 is used. 1

Current Preferred Approach: Conjugate Vaccines First

The 2023 ACIP guidelines fundamentally shifted pneumococcal vaccination strategy away from PPSV23 as a primary vaccine. 1

For vaccine-naïve adults ≥65 years:

• Single dose of PCV20 alone (preferred option for simplicity and comprehensive coverage) 1, 2
• Alternative: Single dose of PCV15 followed by PPSV23 ≥1 year later 1

For adults 19-64 years with chronic medical conditions (diabetes, chronic heart/lung/liver disease, alcoholism, smoking):

• Single dose of PCV20 alone (preferred) 1, 2
• Alternative: PCV15 followed by PPSV23 ≥1 year later 1

For adults 19-64 years with immunocompromising conditions (HIV, malignancy, immunosuppressive therapy, chronic renal failure, asplenia, transplant recipients):

• Single dose of PCV20 alone (preferred) 1
• Alternative: PCV15 followed by PPSV23 ≥8 weeks later (shorter interval due to higher risk) 1, 3

When PPSV23 Is Actually Used

Scenario 1: Sequential Vaccination with PCV15

When PCV15 is chosen instead of PCV20, PPSV23 must follow to complete the series:

• Immunocompetent adults: PPSV23 given ≥1 year after PCV15 1, 3
• Immunocompromised adults: PPSV23 given ≥8 weeks after PCV15 1, 3

The shorter 8-week interval for immunocompromised patients minimizes the time at risk for invasive pneumococcal disease from serotypes unique to PPSV23. 1

Scenario 2: Adults Who Previously Received Only PCV13

• Immunocompetent adults: PPSV23 given ≥1 year after PCV13 1, 2
• Immunocompromised adults: PPSV23 given ≥8 weeks after PCV13 1
• Alternative: Give PCV20 instead (≥1 year after PCV13), which completes the series without needing PPSV23 1

Scenario 3: Second PPSV23 Dose for High-Risk Adults

For adults with immunocompromising conditions who received their first PPSV23 before age 65:

• Second PPSV23 dose given ≥5 years after the first PPSV23 1, 2
• This applies only to immunocompromised patients, NOT to those with CSF leak or cochlear implant alone 1

PPSV23 Dose and Route of Administration

Single 0.5 mL dose administered intramuscularly (preferred route, especially in elderly females due to lower local reaction rates compared to subcutaneous injection). 4

Critical Timing Intervals Summary

Prior Vaccine	Next Vaccine	Immunocompetent Interval	Immunocompromised Interval
PCV15	PPSV23	≥1 year [1]	≥8 weeks [1]
PCV13	PPSV23	≥1 year [1,2]	≥8 weeks [1]
PPSV23 (first dose)	PPSV23 (second dose)	N/A	≥5 years [1,2]
PPSV23	PCV20/PCV15	≥1 year [1,2]	≥1 year [1,2]

Important Caveats and Common Pitfalls

Never co-administer PCV and PPSV23 on the same day. 2, 3 The vaccines must be given at separate visits with appropriate intervals.

PPSV23 has limited duration of protection (unlike conjugate vaccines which provide immunologic memory), which is why conjugate vaccines are now strongly preferred. 1, 5

Prior PPSV23 administration diminishes response to subsequent PCV13 (and likely other conjugate vaccines), making the order of administration critical—always give conjugate vaccine first when possible. 5

For adults ≥65 years who received PPSV23 at age ≥65, only ONE dose of PPSV23 is given—no additional PPSV23 boosters are recommended. 2 The exception is if they later receive PCV15 or PCV20 to complete their series. 1, 2

Avoid unnecessary revaccination: Once PCV20 is administered, the pneumococcal vaccination series is complete and no additional doses (including PPSV23) are needed. 2, 6

Immunocompromising Conditions Requiring Shorter Intervals

The ≥8 week (versus ≥1 year) interval between PCV and PPSV23 applies to: 1, 3

• Chronic renal failure or nephrotic syndrome
• Immunodeficiency (congenital or acquired)
• Iatrogenic immunosuppression (including disease-modifying antirheumatic drugs)
• Generalized malignancy
• HIV infection
• Hodgkin disease, leukemia, lymphoma, multiple myeloma
• Solid organ transplant recipients
• Congenital or acquired asplenia
• Sickle cell disease or other hemoglobinopathies
• CSF leak
• Cochlear implant

Special Population: HSCT Recipients

Adults who received hematopoietic stem cell transplant require a unique 4-dose PCV20 series starting 3-6 months after HSCT, with doses given 4 weeks apart for the first 3 doses, and a fourth dose ≥6 months after the third dose or ≥12 months after HSCT (whichever is later). 1 If PCV20 is unavailable, use 3 doses of PCV15 followed by PPSV23 ≥12 months after HSCT. 1