Pneumococcal disease
Vaccine
Conjugate vaccines
Conjugate vaccines that contain seven (PCV-7), 10 (PCV-10), or 13 (PCV-13) pneumococcal serotypes are now available. These vaccines are licensed for children up to 5 years of age only.
PCV-7, which was marketed in USA in 2001, is widely available internationally for vaccination of children aged 1–5 years. The selection of the included serotypes makes the vaccine suitable for prevention of invasive pneumococcal disease, particularly in the industrialized world.
In 2009, PCV-10 was licensed in Europe and is currently available in many parts of the world for use in children aged 6 weeks to 2 years. In addition to the components of the PCV-7 , the 10-valent vaccine includes three components that also ensure some protection against non-invasive infections, mainly otitis media (middle-ear infection).
PCV-13 was licensed in USA in 2010 and is currently marketed internationally for immunization of children aged 6 weeks to 5 years. The vaccine is also designed for prevention of invasive pneumococcal disease outside the industrialized world and will additionally protect against pneumonia and otitis media caused by these 13 pneumococcal serotypes.
The safety and reactogenicity profiles of PCV-10 and PCV-13 are comparable to that of PCV-7, and compatibility with major childhood vaccines has been demonstrated. The recommended primary vaccination schedule with these PCVs is three doses plus a booster.
Polysaccharide vaccine
The 23-valent polysaccharide vaccine (PPV23) represents pneumococcal serotypes that are responsible for 85–90% of invasive pneumococcal infections in USA and some other industrialized countries. The vaccine is efficacious against invasive pneumococcal disease and pneumonia in otherwise healthy individuals, particularly young adults, but shows limited efficacy in this regard in other age groups, particularly young children; it is licensed only for individuals aged >2 years. The 23-valent polysaccharide vaccine is commonly recommended for children and adults who have certain underlying medical conditions predisposing for pneumococcal infection, although its efficacy in several of these conditions is not well documented. In some countries, such as USA, routine vaccination is recommended for everyone over 65 years of age. For primary immunization, PPV23 is administered as a single intramuscular dose (preferably in the deltoid muscle) or as a subcutaneous dose. The optimal timing, frequency and clinical effectiveness of additional doses of PPV23 are poorly defined, and national recommendations regarding revaccination vary. However, on the basis of the data on the duration of vaccine-induced protection, WHO suggests one single revaccination >5 years after a first vaccination. Local adverse reactions may be more frequent in recipients of a second dose of PPV23 but are generally self-limiting and not severe.