Introduction: Pneumococcus is a common organism causing invasive bacterial disease, especially in children < 2 years and elderly adults. Pneumococcus has more than 90 subtypes. Of these, 10 subtypes cause > 90% of childhood infection.

Disease spectrum: Pneumococcus can lead to invasive diseases like sepsis, meningitis, pneumonia and local infections like ear infection (otitis media) , cellulitis, arthritis, etc. The peak incidence of pneumococcal disease is at 6-24 months of age.

It is estimated that in USA, annually pneumococcus leads to 3000 cases of meningitis, 50,000 cases of sepsis, 500,000 cases of pneumonia and 7 million cases of ear infection with 40,000 deaths. . Vaccination is the only available tool to prevent pneumococcal disease.

There are now vaccines available to prevent infection by some of the common subtypes of pneumoccocal bacteria.

• Unconjugated Pneumococcal Vaccines (PPSV 23): It is active against 23 subtypes of pneumococcus. It is available since several decades. The action is short lived and cannot be used below 2 years of age when it is most required. At best it has efficacy of 70% in healthy adults against invasive disease and only 56% in those > 65 years of age. It is given in children above 2 years of age with sickle cell anemia, splenectomised patients and in patients with low immunity.
• Conjugated Pneumococcal seven valent Vaccine (PCV7): Vaccines against 7, 9 and 11 subtypes have been tried and of this 7 valent conjugated vaccine (Prevenar, PCV 7) is commercially available. While the proportion of various subtypes in children potentially covered by PCV-7 varies markedly from region to region and even from country to country; in most places, at least 50% of subtypes are covered. It resulted in protection of 80% of the pneumococcal disease in infants in the US. In Western Europe, at least two-thirds of all subtypes are covered by PCV-7.
• Conjugated Pneumococcal 13 valent Vaccine (PCV13): World Health Organization noted that the inclusion of additional types beyond the ones included in PCV7 will significantly help to reduce the global burden of pneumococcal disease. A second-generation 13-valent pneumococcal conjugate vaccine (PCV13) was licensed and recommended for universal immunization of children through age 5 years in 2010. This vaccine acts against 6 additional types of pneumococcus as compared to PCV7.
  

Dosing of PCV 13: PCV13 is administered intramuscularly.

Infants and children who have not previously received PCV7 or PCV13: Indian Academy of Pediatrics recommends 3 doses at 6, 10 and 14 weeks with a booster at 15 months. Infants receiving their first dose at age <11 months should receive 3 doses of PCV13 at intervals of approximately 4 weeks with a booster at 15 months. Children aged 12--23 months should receive 2 doses with an interval of at least 8 weeks between doses. Unvaccinated healthy children aged 24--59 months should receive a single dose of PCV13.
Children incompletely vaccinated with PCV7 or PCV13: infants less than 24 months should receive one or more doses based on the number of doses of PCV7 received to date and the age of the child.
Children who have received four doses of PCV7: a single dose of PCV13 is recommended for all children 14 through 59 months of age.
Children 6 through 18 years of age with high-risk conditions: a single dose of PCV13 may be administered for who are at increased risk for invasive pneumococcal disease because of sickle cell disease, HIV infection or other immunodeficiency state, regardless of whether they have previously received PCV7 or pneumococcal polysaccharide vaccine (PPSV) 23.


Complication: 7-valent conjugate vaccine given to infants is a very safe vaccine. Mild local reactions are seen in 30-35% of patients and include redness, warmth, pain, and tenderness. Fever of 38-39 degree C is seen in 25-30% of recipients. Similar side effect profile is expected with the 13 valent vaccine