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Prevention of otitis media in children by pneumococcal vaccination
Insights
The pneumococcal (Pn) polysaccharide vaccine showed poor efficacy in preventing otitis media in infants. Antibody responses were weak, and clinical benefits were minimal, even after two doses.
Area of Science:
- Pediatric infectious diseases
- Vaccinology
- Epidemiology
Background:
- Otitis media is a common childhood illness.
- Pneumococcal bacteria are a leading cause of otitis media.
- Vaccine efficacy against otitis media in infants requires further investigation.
Purpose of the Study:
- To evaluate the efficacy of the 14-valent pneumococcal polysaccharide vaccine in preventing otitis media in infants.
- To assess antibody responses and clinical outcomes following vaccination.
Main Methods:
- A double-blind, randomized trial involving 3,340 infants vaccinated with either pneumococcal vaccine or placebo.
- Two doses of vaccine administered 5 months apart.
- Monitoring of otitis-related visits and acute otitis media incidence.
Main Results:
- Antibody responses to vaccine polysaccharides were generally poor, particularly for types prevalent in otitis media.
- The vaccine showed variable and generally poor effects on otitis media incidence, with no significant reduction observed.
- The second vaccine dose provided no additional serological or clinical benefit.
Conclusions:
- The 14-valent pneumococcal polysaccharide vaccine demonstrated poor efficacy against otitis media in infants.
- Current pneumococcal vaccines may not be effective for preventing otitis media in this age group.
Abstract:
A total of 3,340 infants, 95 per cent of them 7 to 9 months old, were randomly vaccinated in a double-blind fashion with either the 14-valent pneumococcal (Pn) polysaccharide vaccine or a saline placebo in three urban areas in Finland. The second dose of the vaccine was given 5 months later. Age and sex distribution, recruitment of infants, and their otitis-related treatment and follow-up were similar in the study areas. Side effects after vaccination were mild and fewer than among older children. Antibody responses to vaccine polysaccharides varied from type to type, but were generally poor, especially to types most prevalent in otitis media. After the first dose of vaccine, the occurrence of otitis visits among the Pn-vaccinated, as compared with controls, showed inter-area differences, but ranged from not more than a 30 per cent reduction at its best to an increase in some areas and in some clinical categories. The respective figures for children with acute otitis media were similar between the vaccination groups and the study areas. The effect of the vaccine on acute otitis media caused by specific Pn types/groups represented in the vaccine was variable but generally poor. Group 6 attacks especially seemed to behave problematically. The second dose of the vaccine did not give additional benefit serologically or clinically. The efficacy of currently available pneumococcal vaccine against otitis media seemed poor in infants.