Table 1.
Features of Streptococcus pneumoniae polysaccharide and conjugate vaccines
| Vaccine feature | Polysaccharide vaccines (unconjugated) | Conjugate vaccines (protein + saccharide) |
|---|---|---|
| Efficacy for prevention of invasive disease in infants <2 years old1 | No | Yes |
| Vaccine licensed for usage in infants <2 years old1,4 | No | Yes |
| Ability to prevent invasive disease in adults and children >2 years old1,5 | Yes | Yes |
| Recommended for usage in high-risk populations1,6 | Yes | Yes |
| Ability to generate T-cell memory4,6 | No | Yes |
| Ability to prevent colonization with vaccine serotypes1 | No | Yes |
| Number of serotypes in vaccine4,5 | 23 | 7–13 |