ObjectiveTo analyze functional antibody and protection effect against pneumonia after inoculation with 23-valent pneumococcal polysaccharide vaccine(PPV23)in healthy elderly.

MethodsIn 2015, 48 healthy elderly people aged ≥60 years were randomly selected in Hongkou District of Shanghai, and their blood samples were collected before, and 1 month and 6 months after the inoculation of PPV23.Functional antibodies against 13 serotypes(1、3、4、5、6A、6B、7F、9V、14、18C、19A、19F、23F)of streptococcus pneumonia were determined by muti-specificity opsonophagocyitosis killing assay(MOPA).The incidence of community-acquired pneumonia(CAP)after PPV23 inoculation was also investigated.

ResultsThe GMT of OPA antibodies against 13 serotypes were higher 1 and 6 months after inoculation than that before inoculation.One month after the inoculation, OPA antibodies against 13 serotypes ≥2 times growth rate and ≥4 times growth rate were 64.58%-87.00% and 43.75%-75.00%, respectively.Six months after inoculation with PPV23, OPA antibodies against 13 serotypes ≥2 times growth rate and ≥4 times growth rate were 45.71%-82.86%, 40.00%-80.00%, respectively.There was no significant difference in the growth rate of OPA antibody between 6 months and 1 month after vaccination for most serotypes.Results of self-descriptive survey before and after the inoculation showed that the protection against CAP in healthy elderly people in the first and second years after PPV23 inoculation was 100.00% and 50.00%, respectively.

ConclusionPPV23 has better immunogenicity and immune persistence after inoculation in healthy elderly people, and has better protective effect against CAP.