Childhood Ear Infections

New Study Confirms Vaccine Reduces Childhood Ear Infections

(Newstream) -- A vaccine licensed a year ago by the U.S. Food and Drug Administration for the prevention of invasive pneumococcal disease in children has for the first time been confirmed effective in preventing certain childhood ear infections as well, according to a study published this week in the New England Journal of Medicine.

The study found that the trial vaccine, a seven-valent pneumococcal conjugate vaccine, known in the U.S. as Prevnar(r) showed a:

	57% reduction in the episodes of otitis media (ear infections) caused by the seven pneumococcal serotypes targeted by the vaccine;
	51% reduction in the episodes of otitis media caused by pneumococcal serotypes that are closely related (same serogroup) to those targeted by the vaccine;
	34% reduction in the episodes of otitis media caused by any pneumococcal bacteria.

Otitis Media -- A Common Infection in Children

Otitis media is one of the most common bacterial infections in children, striking more than 60% of U.S. children during the first year of life and nearly every child by the age of five. In fact, otitis media is the most common pediatric diagnosis, accounting for 20 million office visits every year in this country and costing the U.S. healthcare system up to $5 billion. Pneumococcus is the most often reported bacterial cause of otitis media, but not the only cause.

About 60% of all acute otitis media infections are caused by bacteria, and 40% of those are caused by pneumococcus. Pneumococcal ear infections are the least likely to get better by themselves. The study showed that the trial vaccine reduced recurrent otitis media by 16% and otitis media from any cause by 6%.

"Previously, there was some evidence that this vaccine could reduce otitis media in children," said Terhi Kilpi, M.D., a researcher at the National Public Health Institute (KTL) of Finalnd and one of the lead investigators in the study. "However because our study identified the pathogen causing the otitis media, for the first time, we were able to confirm that this pneumococcal conjugate vaccine, known in the U.S. as Prevnar(r), is safe and effective in preventing otitis media caused by the seven pneumococcal serotypes the vaccine covers." These seven are among the most resistant to antibiotic treatment and account for more than 80% of pneumococcal infections.

Trial Results

The randomized, double-blind efficacy trial included 1,662 Finnish children who were given either the trial vaccine or the control vaccine at 2, 4, 6 and 12 months. Diagnosis of otitis media was made based on clinical criteria and confirmed by cultures taken from the middle ear fluid. Children were followed up to age 24 months. Together, they experienced 2,596 episodes of otitis media; 685 of those were confirmed to be caused by pneumococcus -414 in the control group compared with 271 in the trial vaccine group. There were 357 episodes caused by one or more of the seven serotypes in the vaccine - 250 in the control group compared with 107 in the trial vaccine group. Of the 125 cases caused by serotypes closely related to those in the vaccine (same serogroup), 84 were in the control group compared with 41 in the vaccine group.

Pneumococcal infections (caused by the bacteria Streptococcus pneumoniae) range from otitis media, sinusitis and pneumonia to the very serious and even life-threatening invasive diseases such as bacteremia (blood stream infection) and meningitis.

Prevnar(r), known outside North America as Prevenar*, is marketed by Wyeth Lederle Vaccines, a unit of Wyeth-Ayerst Laboratories, the pharmaceutical division of American Home Products Corporation (NYSE: AHP).

The study was conducted by the National Public Health Institute (KTL) of Finland and supported by Merck & Co., Inc., Pasteur Merieux Connaught and Wyeth Lederle Vaccines.