Pneumococcal Conjugate Vaccine (PCV15)
Content reviewed against published CDC, AAP, WHO guidelines
Last reviewed:
Key takeaways
- Prevents: Pneumococcal meningitis, Pneumococcal pneumonia
- Schedule: 4 doses starting at 2 months
- Effectiveness: PCV15 is approximately 90-97% effective against invasive pneumococcal disease caused by the serotypes included in the vaccine.
- Most common side effect: Pain, redness, or swelling at injection site
How it works
PCV15 is a conjugate vaccine that contains purified capsular polysaccharides from 15 different strains (serotypes) of Streptococcus pneumoniae, each chemically linked to a carrier protein (CRM197, a nontoxic diphtheria protein). This conjugation allows infants' immature immune systems to recognize and respond to the bacterial sugars, producing protective antibodies and immune memory against the most common disease-causing pneumococcal strains.
Recommended schedule
| Dose | Age |
|---|---|
| Dose 1 | 2 months |
| Dose 2 | 4 months |
| Dose 3 | 6 months |
| Dose 4 | 12-15 months (booster) |
Side effects
Common (mild, resolve in 1-2 days)
- Pain, redness, or swelling at injection site (40-50%)
- Irritability or fussiness (up to 70%)
- Drowsiness or decreased activity
- Fever (up to 40% may have mild fever)
- Decreased appetite
- Muscle aches or joint pain
Serious (very rare)
- Severe allergic reaction (anaphylaxis) — extremely rare
- Febrile seizure — very rare, related to fever rather than vaccine components directly
- No confirmed link to any chronic conditions
Who should NOT get this vaccine
- Severe allergic reaction (anaphylaxis) to a previous dose of any pneumococcal vaccine
- Severe allergic reaction to diphtheria toxoid or CRM197 protein
- Known allergy to any vaccine component
Effectiveness
PCV15 is approximately 90-97% effective against invasive pneumococcal disease caused by the serotypes included in the vaccine. Since pneumococcal conjugate vaccines were introduced (starting with PCV7 in 2000), invasive pneumococcal disease in children under 5 has declined by approximately 90%.
Available brands
Vaxneuvance
Merck
Prevnar 20 (PCV20)
Pfizer (alternative covering 20 serotypes)
Myths vs. facts
Myth: “Pneumococcal disease only affects the elderly”
Fact: Children under 2 years old are actually at the highest risk for invasive pneumococcal disease. Before vaccination, pneumococcus was the leading cause of bacterial meningitis in children under 5 in the US, causing approximately 700 cases of meningitis, 13,000 bloodstream infections, and 5 million ear infections annually in children.
Myth: “The vaccine causes more ear infections”
Fact: The opposite is true. PCV vaccines have significantly reduced ear infections caused by pneumococcus. While other bacteria can still cause ear infections, studies show a 6-7% reduction in total ear infections and a 20% reduction in ear tube placements since PCV introduction.
Myth: “My child doesn't need this if they're healthy”
Fact: Healthy children are absolutely at risk. Before the vaccine, even healthy children without risk factors frequently developed severe pneumococcal infections. The bacteria spread through respiratory droplets and can rapidly cause life-threatening illness in any young child.
Frequently asked questions
What is the difference between PCV15 and PCV20?
Why does my baby need 4 doses?
Can this vaccine prevent ear infections?
Is my child at higher risk if they are in daycare?
Sources
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources
Bottom line
The Pneumococcal Conjugate Vaccine (PCV15) (PCV15) is safe, well-studied, and recommended by the CDC, AAP, and WHO. Talk to your pediatrician if you have questions about timing or your child's specific health needs.
Choosing to vaccinate your child is one of the most important things you can do to protect their health. If you have concerns, your pediatrician is always happy to talk through them with you.