Vaccines Lead to Decline in Complex Otitis Media Incidence

Jenni Laidman

September 04, 2014

The near disappearance of 13 pneumococcal serotypes targeted by vaccine resulted in a 60% fall in the incidence of recurrent, nonresponsive otitis media (OM) in southern Israel, according to a study published online August 25 in Clinical Infectious Diseases.

However, that does not mean OM is about to go away, Richard M. Rosenfeld, MD, MPH, told Medscape Medical News. Dr. Rosenfeld, who is president of the International Society for Otitis Media and professor and chairman of otolaryngology at the State University of New York Downstate Medical Center in New York City, was not involved in the study. "I think you can say that there's something good happening, and there are other studies showing fewer kids get ear tubes when you have vaccinations," he said. But because the Israel study only tracked the most severe cases of OM (ie, OM in children sent for middle ear fluid culture), the incidence of less severe OM was not addressed, nor could it be, as much of it is subclinical.

"The stuff they're putting in these vaccines is the stuff that causes virulent [OM] and causes complications. It doesn't affect the more kinder, gentler type of bacteria that leads to fewer complications," Dr. Rosenfeld said.

In the study, Shalom Ben-Shimol, MD, instructor, Pediatric Infectious Disease Unit, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel, and colleagues analyzed 6122 OM middle ear fluid cultures of children younger than 2 years, taken between July 2004 and June 2013 in southern Israel. The investigators compared the number of OM episodes and the type of bacteria cultured for 3 periods: before pneumococcal vaccination was initiated in Israel, after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7), and after the introduction of PCV13, which gradually replaced PCV7 beginning in November 2010.

PCV7 was licensed in Israel in 2007 and was included in childhood vaccination protocols in 2009. The authors found that OM caused by the pneumococcal strains in PCV7 fell 96% (incidence rate ratio, 0.04; 95% confidence interval, 0.02 - 0.08). The incidence of OM caused by the 5 additional pneumococcal strains in PCV13 fell 85% (incidence rate ratio, 0.15; 95% confidence interval, 0.07 - 0.30). The number of all pneumococcal cases of OM fell 77%, and the incidence of OM from any cause fell 60%.

Before vaccine initiation, the pneumococcal serotypes covered in the PCV vaccines occurred in 30.0 per 1000 OM cases annually, the study showed. By the final year of the study, those serotypes occurred in 10.1 per 1000 OM cases annually, which the authors say translates into 2000 fewer cases of OM per 100,000 children per year.

Of the 6122 OM episodes analyzed, 4028 (66%) of these were culture-positive and 1893 (47% of positive cultures) were positive for Streptococcus pneumoniae. In 1093 cultures (58% of pneumococcal episodes), S pneumoniae was the only isolate. Haemophilus influenzae appeared most frequently in the remaining 800 cultures.

One coauthor reports receiving grants and support from Berna/Crucell, MSD, and Pfizer; performing consultant work for Berna/Crucell, GlaxoSmithKline, MSD, Novartis, and Pfizer; and receiving speaker's fees from Berna/Crucell, GSK, and Pfizer. Another coauthor reports receiving research support from MSD, has been a consultant for GSK and MSD, and received a speaker's fee from both companies and Pfizer. Another coauthor has been a speaker for Pfizer and GSK. The other authors and Dr. Rosenfeld have disclosed no relevant financial relationships.

Clin Infect Dis. Published online August 25. Abstract


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