24 valent pneumococcal polysaccharide conjugate vaccine(MSD)

ABSTRACT. The IgG and IgM type specific anticapsular pneumococcal antibody titres were studied with ELISA during one year following vaccination with a 14‐valent pneumococcal polysaccharide vaccine in four different patient groups: 41 children splenectomized after a traumatic rupture, 16 splenectomized because of disease, 15 non‐surgically managed after splenic rupture, and 19 healthy controls. Serum samples were obtained before vaccination and after 14, 60, 180, and 360 days. The IgG antibody responses were equally good in all of the patient groups, while the IgM antibody responses were less pronounced in the splenectomized. In the non‐surgically managed patients, the IgM antibody titres after vaccination, as well as antibody responses per se, were significantly higher for all 12 pneumococcal types studied than in the patients who were splenectomized. Both the IgG and the IgM antibody titres were highest at 14 days after vaccination. However, while the IgG titres for most pneumococcal types remained elevated at 360 days, the IgM titres soon fell to prevaccination levels. The antibody response was less good for the types 3 and 6 A. The results indicate that the IgG antibody response to pneumococcal polysaccharide vaccination is unaffected in splenectomized individuals, but the IgM antibody response is decreased. In patients with a healed traumatically damaged spleen, both the IgG and IgM responses seem to be normal.

The incidence of pneumoccal meningitis in Danish children during 1969–1978 was estimated to be 2.1/year/100,000 children from 0 to 14 years old. Fifty‐five per cent of 146 children with pneumococcal meningitis and 61% of 61 with bacteraemia were below 2 years of age. Mortality from meningitis was 13% and from bacteraemia 7%. Of the children with meningitis, 14% had sequelae at the time of discharge from the hospital. Sequelae were not seen after bacteraemia. Among 277 pneumococcal isolates from spinal fluid and blood from Danish children during 1969–1978, serotypes 14, 18C, 6A + 6B, 23F, 7F and 19F, in that order of frequency, were the most common ones, accounting for 69% of all isolates. Serotypes included in current 14‐valent pneumococcal polysaccharide vaccines made up 81% of all types, when types 6A and 6B are considered together (because it has been shown that they offer cross‐protection).