This vaccine wasn’t meant to prevent ear infections per se, but has had the welcome side effect of doing just that (for more on ear infections, go here). Pharmaceutical company Wyeth developed the vaccine PCV7 (marketed in the US under Prevnar) to ward off common bacterial infections, and has been around since 2000. However, children who received the vaccine had significantly less ear infections and a lower incidence of “tubes in the ears.” (For more on ear tubes, go here.)

The vaccination, given initially at 2, 4 and 6 months of age, was designed to combat a number of pneumococcal infections, including ear infections that most children have at least once by the time they turn 2 years old.

But Poehling said the new research shows that the vaccine also was preventing repeat infections, which occur three or four times a year in up to nearly a third of all children, often requiring the insertion of ear tubes to equalize pressure.

The vaccine also has helped adults, she said, by preventing the general spread of disease.

The study was published in the current issue of Pediatrics, and examined data from more than 150,000 children in Tennessee and another 26,409 in upstate New York. Below is a graph which follows the number of infections per year (tracked in NY), starting in 1998/1999. The vaccine was introduced in 2000, which represents a fall in the number of infections and a gradual continual decline until the end of data collection (2003).

Poehling et al. 2007. Reduction of Frequent Otitis Media and Pressure-Equalizing Tube Insertions in Children After Introduction of Pneumococcal Conjugate Vaccine. PEDIATRICS Vol. 119 No. 4, pp. 707-715.