[Reactogenicity, safety, immunogenicity and prophylactic effectiveness of polysaccharide pneumococcus vaccine during immunization of HIV-infected patients]

Abstract

Aim: Study safety, reactogenicity, immunogenicity and prophylactic effectiveness of polysaccharide pneumococcus vaccines during immunization of adult HIV-infected patients.

Materials and methods: 200 HIV-infected patients at stages 3 to 4A of the disease aged 20 to 50 years with the quantity of CD4+ T-lymphocytes in blood of no less than 500 microl(-1) took part in the study. 100 individuals immunized with polysaccharide 23-valent pneumococcus vaccine (Pneumo 23, Sanofi Pasteur, France) constituted the observation group. 100 individuals not immunized against pneumococcus infection constituted the comparison group. The groups were standardized by sex, age and disease stage. Vaccine reactogenicity was evaluated by detection of general and local postvaccination reactions, degree of their intensity and duration. Vaccine safety was evaluated based on comparative evaluation of results of general clinical and biochemical studies of blood, general urine analysis, determination of IgE in blood sera, CD4+ T-lymphocytes level, quantity of HIV RNA (viral load) before vaccination and 28 days after the immunization. Vaccine immunogenicity was evaluated by determination in blood sera of IgG against a mixture of Streptococcus pneumoniae polysaccharides comprising Pneumo 23. Prophylaxis effectiveness of the preparation was evaluated by juxtaposition of acute respiratory illness morbidity in observation and control groups.

Results: During immunization of HIV-infected patients against pneumococcus infection postvaccination complications, severe local and general postvaccination reactions were not detected, laboratory studies carried out before and after the immunization gave evidence on the lack of progression of the main disease and activization of the infectious process. After the immunization the geometric mean antibody titer against S. pneumoniae increased by 2 times and reached protective level. Index of prophylactic effectiveness of Pneumo 23 vaccines during immunization of HIV-positive patients was 5.6, and relative risk of the disease in the immunized group--0.07, in the control group--0.42.

Conclusion: The data provided give evidence on the high prophylactic effect of vaccination of immune compromised HIV-positive patients with a lack of deterioration of the main disease course.