Otitis media accounts for more than 20 million physician office visits by children in the United States every year. Although most cases resolve without sequelae, some cause hearing loss. Vaccines against the seven most common pneumococcal serotypes have been shown to effectively prevent otitis media caused by those serotypes. Prymula and colleagues studied a novel vaccine against the major pathogens responsible for otitis media: Streptococcus pneumoniae and Haemophilus influenzae. This vaccine incorporates a surface lipoprotein of H. influenzae (protein D) into an 11-valent pneumococcal vaccine.
The randomized, double-blind study included healthy infants visiting physician offices in Slovakia or the Czech Republic for routine health care. After being evaluated for contraindications, eligible children were randomly assigned to receive the new pneumococcal vaccine or the hepatitis A vaccine at three, four, five, and 12 to 15 months of age. The children were screened for otitis media until 24 to 27 months of age. Parents were encouraged to consult the physician if their child developed ear pain, aural discharge, or acute illness. The physicians used standard criteria to diagnose otitis media during the follow-up period. Patients with clinical otitis media were referred to a subspecialist for confirmation of the diagnosis, and tympanocentesis was performed for bacterial testing.
The two groups of children were comparable in important variables, including exposure to children outside of the household. During follow-up, 366 of the 2,489 children who received the pneumococcal vaccine developed acute otitis media compared with 553 of the 2,479 children who received the hepatitis A vaccine. These results were equivalent to 83.3 episodes per 1,000 person-years in the pneumococcal vaccine group and 125.2 episodes per 1,000 person years in the hepatitis A vaccine group. The effectiveness of vaccination against the first episode of acute otitis media caused by pneumococcal serotypes was 52.6 percent, and vaccination was more than 30 percent effective against nontypeable H. influenzae. Although adverse events within 31 days of vaccination were reported by almost one half of children in each group, adverse events attributable to vaccination were documented in only 2 to 3 percent of children in either group.
The authors conclude that the new pneumococcal vaccine provided protection against otitis media caused by pneumococci and nontypeable H. influenzae.