BACKGROUND: A new vaccine has been developed that can help reduce the number of infants and toddlers who develop frequent ear infections. It has been available since 2000, but a new study demonstrates its effectiveness against seven especially virulent strains of the bacteria that cause such infections.
WHAT THEY FOUND: A team of researchers at Wake Forest University Baptist Medical Center tracked some 27,000 children in New York, and 150,000 children in Tennessee from birth to age two -- all born after a vaccine was approved by the FDA to help protect children from potentially deadly strains of meningitis and other pneumococcal (a type of bacteria) diseases such as ear infections. The children received four doses of the vaccine: at two months, four months, six months, and between 12-15 months. The researchers found that number of children who developed frequent ear infections declined by 16% in Tennessee and 25% in New York after receiving the vaccine. They also found declines in the incidence of serious cases of pneumococcal meningitis on both children and adults. Most children develop at least one ear infection by their second birthday, and 25 to 30 percent will experience frequent infections. Of those, one in every 15 to 25 will need to have ear tubes implanted by age two. Before the vaccine was introduced, about one-third of ear infections were caused by the pneumococcal bacteria. However, there are 90 known strains of the bacteria; the vaccine only protects against seven of them.
ABOUT EAR INFECTIONS: There are three main parts to the human ear: outer, middle and inner ear. The outer ear is the part you can see and opens into the ear canal leading to the middle ear. The middle ear is a closed, air-filled chamber, separated from the outer ear by the ear drum, and ventilated by the Eustachian tube. Sometimes the pressure in the middle ear becomes higher or lower than that in the outer ear, causing hearing loss, severe pain, and the accumulation of fluid in the middle ear. The inner ear contains the hearing nerve that leads to the brain. It detects sound vibrations and turns them into electrical nerve impulses, which the brain then interprets as sound. Chronic middle ear fluid is a condition known as otitis media with effusion (OME).When this condition becomes persistent, and antibiotics aren't effective, it is often treated with surgical insertion of ear ventilation tubes. More than 700,000 children undergo this procedure each year. But the tubes often fall out within four to seven months, and the patients have a recurrence of the condition.
HOW VACCINES WORK: Whenever a disease-causing micro-organism enters the body, the immune system mounts a defense, producing proteins to fight off the foreign substance. Vaccines stimulate the body's immune system by introducing a weakened form of a particular germ or virus, making the body think it is being invaded by a foreign organism. If a person who has been vaccinated is exposed later to the virus, he or she will be protected because the body already has the necessary antibodies to ward off infection.