An Overview of Pneumococcal Conjugate Vaccine

Streptococcus Pneumoniae or Pneumococcus is a gram-positive bacteria which causes besides Pneumonia, acute sinusitis, acute suppurative otitis media, meningitis, sepsis, brain abscess and other such serious infections.

Pneumococcus primarily affects children in the pre-school age group of 3 months to 5 years while most serious infections occur in the first 2 years of life. All children below 2 years of age should take Pneumococcal Conjugate Vaccine while only at-risk children between 2-5 years of age should take the Pneumococcal Polysaccharide 23-Valent Vaccine.

Only Pneumococcal Conjugated Vaccines can be given in children below 2 years of age. Although many serotypes of bacteria are responsible for disease, the seven most common serotypes are currently covered by the Pneumococcal Conjugate Vaccines like Prevanar are available in the market. Though 23-valent Polysaccharide Vaccines are available like Pneumo-23 but they cannot be given to children below 2 years of age.

Both Pneumococcal Vaccines are made from inactivated, killed bacteria and are given intra-muscularly by injection. The schedule varies according to the age at which the child presents though commonly followed is a 4-dose schedule including a booster dose given 1 year after revieving 3 doses at an interval of 2 months starting from 2 months of age.

Pneumococcal Conjugate Vaccine is relatively safe apart from very mild side-effects like redness and pain at the site of injection. Mild fever or slight muscle ache are reported by few while allergic reactions are very rare.

Pneumococcal Conjugate Vaccine has been reported to have an efficacy of 97% against serotypes covered by it in a clinical trial. Only children with severe allergic reaction to previous dose should avoid receiving further doses otherwise safety is fully established.

One prohibitive factor, which specially constraints the mass use especially in developing countries, is the high price. Efforts are underway to produce cheaper Pneumococcal Conjugate Vaccines covering more serotypes. In fact, Wyeth has already launched a 13-Valent Pneumococcal Conjugate Vaccine which should offer a better and wider protection against newer serotypes in children below 2 years of age.